This prerequisite establishes a baseline for providing a minimum amount of outdoor air to buildings in order to maintain good indoor air quality and keep occupants comfortable and healthy. This prerequisite references ASHRAE 62.1-2007 (with errata but without addenda) and is often more stringent than local building codes, although it is not likely to entail any added costs.
The compliance paths for mechanically ventilated and naturally ventilated spaces, Case 1 and Case 2, are somewhat different and you may need to follow both paths for the same building on a space-by-space basis. Spaces served only by natural ventilation must follow the distinct requirements set out in Case 2, even if other spaces in the same building are mechanically ventilated and are following Case 1. Mixed-mode spaces which alternate between natural or mechanical ventilation must follow the compliance path for mechanical ventilation, Case 1.
For additions and major renovations, confirm that all ventilation systems serving the project meet the ventilation rates required by ASHRAE 62.1 2007, even if the ventilation system design itself is outside the scope of the project. If base building systems do not meet the standard’s requirements, you will need to either increase ventilation rates to comply or provide detailed analysis documenting the constraints and explaining why the base building systems cannot be upgraded.
There’s some confusion in this language on whether mixed-mode refers to a ventilation design with both natural and mechanical ventilation all the time, which needs to be divided up to show compliance, or to a system where either is optional, in which case the worst-case design conditions are for when only the mechanical systems are used and window are shut.
Commercial interior projects will need to confirm that any ventilation systems serving the project meet the ventilation rates required by ASHRAE 62.1-2007, even if the ventilation system design itself is outside the scope of the project. If base building systems cannot be modified to meet the standard’s requirements, you will need to provide detailed analysis documenting the constraints and explaining why the base building systems cannot be upgraded. Systems must be able to provide at least 10 cfm per person to meet this prerequisite.
The 2007 edition of ASHRAE 62.1 combines 62.1-2004 and the eight approved and published addenda to the 2004 edition. The new edition does the following:
If the building relies on the fans for daily ventilation, it is considered a mechanically ventilated building.
Testing in naturally ventilated spaces is not required per 62.1-2007 Sections 4-7 if the outdoor air quality adequately meets 62.1-2007, Table 4-1.
Both operable windows and vents can be used, but only the operable area within those elements can be counted towards the minimum percentage (4%) of net occupiable area.
Local codes may be used to meet the prerequisite if the project team can show equivalency with Sections 7 through 7 of ASHRAE Standard 62.1-2007. Projects outside the US can now also choose to comply with the minimum requirements of Annex B of CEN Standard EN 15251:2007 Ventilation for Nonresidential buildings.
Teams may choose to substitute ASHRAE 62.1-2010, Sections 6.4.1-6.4.2, for ASHRAE 62.1-2007, Section 5.1.1, to document compliance with IEQp1 for naturally ventilated buildings. ASHRAE 62.1-2010 adds geometric requirements that extend the allowed naturally ventilated floor area based on ceiling height and opening configuration.
For CI projects, calculations must be done at the system level for any AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition)
2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork. providing outside air to the tenant spaceTenant space is the area within the LEED project boundary. For more information on what can and must be in the LEED project boundary see the Minimum Program Requirements (MPRs) and LEED 2009 MPR Supplemental Guidance. Note: tenant space is the same as project space..
Determine likely ventilation strategies during preliminary programming: natural, mechanical, or mixed-mode ventilation. This prerequisite is attainable with any of these strategies.
This prerequisite is paired with IEQc2: Increased Ventilation. If ventilation rates are targeted above the 30% ASHRAE requirement, projects can gain both the prerequisite and a point for EQc2. Projects pursuing IEQc2 may follow the compliance path for natural ventilation found in Chapter 2 of The CIBSE Applications Manual 10 (AM10) for both the prerequisite and for the credit.
Many of the strategies that contribute to meeting this prerequisite also support earning other indoor environmental quality credits and should be explored as integrated solutions. See LEEDuser's guidance on the rest of the IEQ section for ideas.
Natural ventilation strategies can reduce costs. Natural ventilation in particular can reduce the need for mechanical equipment as well as operational costs. Displacement ventilation, in which air is delivered at or near floor level at a low velocity, can also reduce ducting and improve equipment efficiency. In choosing a system, analyze life cycle cost tradeoffs.
Check local building codes to determine requirements. The project must either meet ASHRAE 62.1-2007, or local codes if they are more stringent. Since ASHRAE 62.1-2007 is often more stringent than local codes, be sure to review and be familiar with its requirements.
This prerequisite is not likely to require added costs.
Review the Ventilation Rate Procedure methodology in ASHRAE 62.1-2007 Section 6.2 and the associated Table 6-1.
ASHRAE 62.1 recognizes two procedures to prove IAQ compliance: the IAQ Procedure methodology and the Ventilation Rate Procedure. The Ventilation Rate Procedure is easier to apply and is the prescribed path for this LEED prerequisite. Documentation using the IAQ Procedure requires the quantification of contaminant source emissions rates and their reduction, and has historically not been accepted for this prerequisite because it is performance-based and difficult to compare across projects.
If you are pursuing IEQc5: Indoor Chemical and Pollutant Source Control, you must incorporate MERV 13 filters into your filtration system. These relatively tight filters may affect the fan power and fan sizes necessary to provide the required quantities of air. Involve the engineer early if pursuing IEQc5.
Demand-controlled ventilation can greatly reduce energy use while providing large amounts of fresh air to occupants.
Determine whether natural ventilation is feasible based on the project type, use, and climate. Study the natural conditions of the site, such as prevailing wind direction, and orient the building to maximize airflow.
Review the prescriptive requirements for natural ventilation in ASHRAE 62.1-2007 Paragraph 5.1 (with errata but without addenda).
An integrated design meeting will help determine whether natural ventilation is a high priority and should be a primary driver of the design process.
Airflow modeling early in the design process can help teams by evaluating which space planning and envelope design strategies will create effective natural ventilation. An airflow modeling professional may add some upfront costs, while likely improving system efficiency.
Airflow modeling can also help to determine compliance for an engineered natural ventilation system outside the prescriptive measures of ASHRAE 62.1-2007.
Consider the cost implications of natural ventilation. Passive strategies may reduce or eliminate the need for fans and HVAC equipment, but they may also require high quantities of operable windows and a floor plan that is conducive to passive ventilation. Natural ventilation often requires the cooperation of occupants, to open and close windows when appropriate, for example, be sure that your project is likely to succeed in this respect.
Determine the required ventilation rates for indoor spaces based on occupancy and space types. ASHRAE 62.1-2007 tables 6-1 and 6-4 list minimum requirements for particular spaces.
Separately evaluate each space to determine air requirements and what type of ventilation will be best. Metabolic rate of the space activities and the occupant density are factors that determine the amount of fresh air needed in a space. For example, exercise rooms and conference rooms require more fresh air than offices.
An integrated design approach among the mechanical engineer, architects, owners and occupants will facilitate design decisions that impact the HVAC design. For example, space planning decisions will impact the architectural programming of the space as well as access to natural ventilation.
Increasing a project’s ventilation rate brings long-term cost benefits. Good indoor air quality can lower operational costs by increasing occupants’ health and productivity as well as the value and marketability of the building.
For mixed-mode and naturally ventilated spaces, the mechanical engineer should calculate the outdoor airflow rate and communicate the area requirements for operable wall or roof openings to the architect.
The mechanical engineer begins preliminary ventilation rate calculations during project programming in order to set ventilation quality goals for particular spaces and occupancies. The area of a given multi‐zone system should be broken down by ventilation zones, and all zones within that system must meet the minimum breathing zone ventilation air requirements as per ASHRAE 62.1‐2004. For a typical office space, the mechanical design consists of multiple ventilation zones for which compliance would need to be shown on an individual basis.
For mixed-mode ventilation, zone the plan into areas—mechanically ventilated and naturally ventilated—and follow separate compliance calculations for each area.
Determine the applicable floor area for operable wall or roof openings according to ASHRAE 62.1-2007 section 5.1.
Consider using Computational Fluid Dynamics (CFD) modeling to determine proper opening sizes and ensure proper airflow. Some energy modeling programs also have CFD analysis capabilities.
Expect upfront modeling fees for Computational Fluid Dynamics (CFD), but also consider the benefits of CFD modeling: a better-designed natural ventilation system that can bring short-term payback from reduced mechanical systems, and long-term operational savings.
At the first integrated design meeting during schematic design, develop a detailed natural ventilation strategy involving goals for windows, building orientation, space planning, use of atriums, and other access to natural ventilation. Natural ventilation systems may require a more robust and intense integrated design process, of several focused workshops analyzing several alternatives. Computer modeling may be necessary to test various design alternatives to determine which is most effective and efficient.
Hotel and multifamily projects may have difficulty achieving this prerequisite if they are naturally ventilated and have interior spaces that are further than 25 feet from an operable wall or roof opening. These projects might consider increased window areas, shallower floor plates, or using mixed-mode ventilation so that mechanically supplied outdoor air can support areas outside the 25-foot natural ventilation boundary.
The mechanical engineer continues to run ventilation rate calculations during the mechanical design process to inform design development and confirm compliance with this prerequisite. The ventilation rate procedure is explained in section 6 of ASHRAE 62.1-2007. See the attached 62MZ calculator.
Continuing to use an integrated design approach among the mechanical engineer, architects, owners and end users will facilitate design decisions that impact the mechanical design. For example, space planning decisions will impact the architectural programming of the space as well as access to natural ventilation.
Strategically locate air intakes for mechanical or natural ventilation systems to avoid taking in contaminants and odors like vehicle exhaust from parking lots or fumes from garbage storage areas.
Incorporating operable windows into the design for natural and mixed-mode ventilation can help with an additional LEED point for EAc6.1: Controllability of Systems—Thermal Comfort.
Continue running ventilation rate calculations during the mechanical design process to confirm compliance with this credit and to inform the design. The ventilation rate procedure is explained in section 6 of ASHRAE 62.1-2007. See the 62MZ calculator.
Implement energy recovery systems, economizers, low-pressure-drop design, and efficient fans as appropriate to support ventilation rates meeting or exceeding the referenced ASHRAE standard without compromising energy performance.
Avoid oversizing mechanical equipment. Oversized equipment will often increase operating costs and reduce operational efficiency. The correct equipment size will depend on a number of factors, including local climate, total building area, insulation levels, air filtration medium, number of windows and doors, and occupant comfort preferences.
Spaces served by the same VAV (variable air volume) controller can be grouped together in the 62MZ calculator, but grouped spaces should have similar exterior exposure. For example, you can group two perimeter spaces that share a VAV controller, but would want to separate a non-perimeter space even if it shares the same VAV controller.
Laboratory facilities generally require very high ventilation rates. Consider installing separate mechanical systems for lab spaces to maximize return-air mixing. Other strategies may include using a heat exchanger to capture energy from laboratory exhaust, using low-flow or variable-flow fume hoods, minimizing ventilation rates during unoccupied times, or using a dedicated outdoor air system.
Integrating building automation systems can control mechanical systems efficiently and maintain desired ventilation rates while minimizing unscheduled maintenance.
The Ventilation Rate Procedure calculation includes occupancy counts based on space types.
Continue to run calculations and develop flow diagrams to inform the design process and confirm compliance. If you are using a natural ventilation modeler for the project, use the model as a tool to inform design development.
The calculation for operable openings will only apply to the floor area adjacent to the window—25 feet to either side and in front of the opening.
The surface area of window openings must, for compliance with ASHRAE 62.1, be equal to or greater than 4% of the occupied floor area that the design considers naturally ventilated. Multiple windows in aggregate can provide the operable area needed to meet the requirements.
In naturally ventilated multifamily buildings, air infiltration from a pressurized hallway or corridor can contribute to the Ventilation Rate Procedure calculation for areas that do not meet the requirements of ASHRAE 62.1, as long as the corridor is pressurized with outdoor air.
For mechanically ventilated spaces, run ventilation calculations to verify that the final design meets the minimum outside air rates equal to or exceeding the ASHRAE 62.1-2007 minimum.
For naturally ventilated spaces, confirm compliance with the requirements of ASHRAE 62.1-2007 section 5.1.
If natural ventilation strategies are integrated into the design, ensure that key elements of the natural ventilation system, such as operable windows, window actuators, controls, operable atrium elements, and solar chimneys, are not compromised during value engineering. Educate decision-makers about the natural ventilation design and the importance of maintaining all the key components. If these elements are altered in a way that compromises natural ventilation rates, the mechanical system may no longer be sized appropriately.
Fill out the LEED credit form and upload all supporting documents to LEED Online.
Use this checklist for naturally ventilated spaces prior to construction to review plans for prerequisite compliance:
Use this checklist for mechanical systems prior to construction to check prerequisite compliance:
Coordinate the installation of ventilation systems with the project’s commissioning process.
Use commissioning to confirm that installed systems are providing the outside air rates specified in the design.
Monitor outdoor air delivery periodically to confirm that minimum ventilation rates are being maintained. Implement a maintenance program to ensure that mechanical system components are functioning properly.
Test all dedicated building exhaust systems including chemical areas, bathroom, shower, kitchen, and parking exhaust systems to confirm proper fan speed, voltage, control sequences, and set points as applicable. Provide operations and maintenance personnel with manuals and educate them about any atypical maintenance requirements.
Getting feedback on ventilation performance from occupants through surveys can help to identify potential problems that may become expensive if they go unnoticed.
A documented ventilation performance plan can help ensure that systems reach the expected ventilation thresholds.
In projects with operable windows, occupants may not know when conditions are best for opening the windows. Implement a system so that occupants are informed of when to open and close the windows to achieve designed performance and optimal comfort.
Maintain a building operating plan (BOP) that establishes operating schedules and set points and regularly review these parameters against actual building needs. When developing these parameters, consider both time-of-day and time-of-year variations in optimal temperature requirements and be careful to avoid over-conditioning the building spaces with more ventilation, heating or cooling than is necessary.
Adjust reset and setback temperature settings and calibrate controls and sensors. A Building Automation System (BAS) will allow building managers to adjust, monitor and control temperature set points and air volumes throughout the building from a central location. Direct digital controls (DDC) utilized by the BAS will function more efficiently than older pneumatic controls and help to avoid unnecessary use of HVAC equipment during non-business hours and holidays.
Develop and implement a comprehensive Indoor Air Quality Management Plan using the EPA’s “Indoor Air Quality Building Education and Assessment Model” (I-BEAM).
Following the initial audit, the IAQ manager must make periodic inspections to uncover new IAQ issues and monitor the status of previous issues. The I-BEAM tool supplies inspection forms that can be tailored to the project building to facilitate this process.
Establish protocols to manage all significant pollutant sources referenced in I-BEAM that are applicable to the project building.
Ensure that procedures are in place for receiving and responding to IAQ complaints from building occupants. The I-BEAM tool provides sample forms and logs for fielding and recording occupant complaints as well as information about key principles for developing effective communication with building occupants regarding IAQ issues. Strategies for investigating and resolving the issues that trigger occupant complaints are covered by a variety of I-BEAM guidelines.
Excerpted from LEED 2009 for New Construction and Major Renovations
To establish minimum indoor air quality (IAQIndoor air quality: The quality and attributes of indoor air affecting the health and comfort building occupants. IAQ encompasses available fresh air, contaminant levels, acoustics and noise levels, lighting quality, and other factors.) performance to enhance indoor air quality in buildings, thus contributing to the comfort and well-being of the occupants.
CASE 1. Mechanically Ventilated Spaces
Mechanical ventilation systems must be designed using the ventilation rate procedure as defined by ASHRAE 62.1-2007, or the applicable local code, whichever is more stringent.
Meet the minimum requirements of Sections 4 through 7 of ASHRAE Standard 62.1-2007, Ventilation for Acceptable Indoor Air Quality (with errata but without addenda). Projects outside the U.S. may use a local equivalent to Sections 4 through 7 of ASHRAE Standard 62.1-2007.
Projects outside the U.S. may earn this prerequisite by meeting the minimum requirements of Annex B of Comité Européen de Normalisation (CEN) Standard EN 15251: 2007, Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics; and the requirements of CEN Standard EN 13779: 2007, Ventilation for nonresidential buildings, Performance requirements for ventilation and room conditioning systems, excluding Section 7.3 – Thermal environment, 7.6 – Acoustic Environment, A.16, and A.17.
CASE 2. Naturally Ventilated Spaces
Naturally ventilated buildings must comply with ASHRAE Standard 62.1-2007, Paragraph 5.1 (with errata but without addenda). Project teams wishing to use ASHRAE approved addenda for the purposes of this prerequisite may do so at their discretion. Addenda must be applied consistently across all LEED credits.
Design ventilation systems to meet or exceed the minimum outdoor air ventilation rates as described in the ASHRAE standard. Balance the impacts of ventilation rates on energy use and indoor air quality to optimize for energy efficiency and occupant comfort. Use the ASHRAE Standard 62.1-2007 Users Manual (with errata but without addenda1) for detailed guidance on meeting the referenced requirements.
1 Project teams wishing to use ASHRAE approved addenda for the purposes of this prerequisite may do so at their discretion. Addenda must be applied consistently across all LEED credits.
This updated version of the spreadsheet categories dozens of specific space types according to how they should be applied under various IEQ credits. This document is essential if you have questions about how various unique space types should be treated. Up to date, 2nd Edition.
ASHRAE 62.1-2007 should be referenced when designing outdoor airflow monitoring devices.
This spreadsheet categories dozens of specific space types according to how they should be applied under various IEQ credits. This document is essential if you have questions about how various unique space types should be treated. This is the 1st edition.
This Rocky Mountain Institute publication is a case study of the connection between worker productivity and indoor air quality.
This manual provides information on the technology and techniques for the design, operation, servicing, and balancing of environmental systems.
ASHRAE publishes widely used standards and publishes the ASHRAE Journal.
Labs21 is a voluntary partnership program dedicated to improving the environmental performance of U.S. laboratories.
IAQA is a nonprofit organization dedicated to promoting the exchange of indoor environmental information through education and research.
MSCA is a national trade association that provides educational resources and training programs on sustainable service and maintenance practices for HVACR contractors.
Located in London, this organization publishes a series of guides on ventilation, including natural ventilation.
This website contains reports from an extensive EPA modeling study that assessed the compatibilities and trade-offs between energy, indoor air quality, and thermal comfort objectives for HVAC systems and formulated strategies to achieve superior performance.
This is a Microsoft Excel calculator that accompanies the ASHRAE 62.1 reference standard. The calculator allows users to plug in variables for specific project types and run the Ventilation Rate Procedure.
Public domain software from NIST (National Institute of Standards and Technology) that has natural ventilation sizing tools, and flow models to analytically predict room-by-room airflows.
Public domain software from NIST (National Institute of Standards and
Technology) that has natural ventilation sizing tools, and flow models
to analytically predict room-by-room airflows.
ASHRAE released an app for iPhone, iPod touch, and iPad that allows you to perform comprehensive minimum ventilation calculations for a wide variety of commercial buildings based upon Standard 62.1, using either I-P or SI units. This app is based upon the 62MZCalc.xls. Now, you can make calculations at a meeting and know if your project meets IEQp1 or IEQc2.
This example ventilation rate table from 23 High Line provides guidance when developing prerequisite compliance documents for your project.
This example air riser diagram from 23 High Line shows the mechanical ventilation supply for the building. It is the ducted diagram showing how air will be supplied to building occupants. Use this as an example for how to document ventilation effectiveness compliance.
Use this example mechanical schedule created from 23 High Line for guidance when developing ventilation effectiveness compliance documents for your project.
The following links take you to the public, informational versions of the dynamic LEED Online forms for each NC-2009 IEQ credit. You'll need to fill out the live versions of these forms on LEED Online for each credit you hope to earn.
Version 4 forms (newest):
Version 3 forms:
These links are posted by LEEDuser with USGBC's permission. USGBC has certain usage restrictions for these forms; for more information, visit LEED Online and click "Sample Forms Download."
Documentation for this credit can be part of a Design Phase submittal.
The Global compliance Path guide book gives the option between ASHRAE 62.1-2007 or European standards EN 15251: 2007 and EN 13779: 2007.
Can we use the ventilation rates described in the ASHRAE 62.1 in regularly occupied spacesRegularly occupied spaces are areas where one or more individuals normally spend time (more than one hour per person per day on average) seated or standing as they work, study, or perform other focused activities inside a building. (Table 6.1, 6.2, 6.3) and the extraction rates (e.g. bathrooms) described in the CEN Standards EN 15251: 2007 and EN 13779: 2007 in in non-regularly occupied rooms (bathrooms) and achieve credit compliance?
If the French extraction rate is higher than the CEN / EN standard can it replace them?
I do not think they will accept combining both methodologies unless you have a good reason for doing that, for instance, if you your project has a type of space that is not covered in one of the standards.
My advise is that you should use the ASHRAE calculator because the reviewers are usually not familiar with the CEN standard.
I agree with Gustavo in that GBCI would accept one path or the other and not a mix of it. I have submitted projects using the european standrads and it has been accepted without any problem.
The credi focus is the minimum rates so if your rates are higher on your design it isnt a problem.
Our project is a large high rise dorm consisting of 4-person suites arranged typically as a 2BR and two 1BR's connected by a short inner hallway. The suite has a shared single bathroom accessible from the inner hallway. The inner hallway is very narrow and not occupiable for any duration. Our current scheme includes bathroom exhaust at 50-cfm continuous. Fresh air (neutral, i100% outside air) is delivered at 50-cfm to the hallway only (not each bedroom). The 50-cfm of OA meets the total suite ventilation requirement based on the 5-cfm/person + 0.06 cfm/sf requirement of ASHRAE 62.1-2007. The doors to each bedroom are undercut to allow the fresh air into the bedrooms.
Would the above scheme meet the requirements for mechanical ventilation per ASHRAE 62.1 for all spaces in the dorm suite?
No, that would not meet the requirements for mechanical ventilation. Mechanical ventilation should have some way of making the air come into the occupiable space.
Any chance the bedrooms have operable windows such that they meet the naturally ventilation requirements in terms of size, while the inner hallway is mechanically ventilated?
I am working on LEED boundary for Factory building. The factory has two buildings with common car parking but we are applying LEED certification for only building - 1. Moreover, the car parking is near to building - 2 and a bit far away from building - 1. To achieve SSCR 7.2 Heat Island Reduction - Non roof, should i include parking area in LEED boundary?
You should ask this on the SSc7.2 forum. Tristan may be able to relocate it for you.
My project is a 93,000 sf open-plan hangar. We are designing grills on walls that count for 4% of the floor area on 2 opposite facades to induce crossed-ventilation. Has anyone tried this strategy successfully in a project before?
My concern is that it is a big space and I am afraid the reviewer will ask for mechanical ventilation.
For natural ventilation, all occupiable space should be within 25' of an opening. If you do not meet this, then I would recommend adding exhaust fans to draw the ventilation air through the openings. You are allowed to control this based on CO2Carbon dioxide levels in the space.
As Andrew has noted, if any part of the space is further than 25' (8 m) away from those openings, the LEED reviewers will have a questions. We have used a similar strategy on large warehouse and manufacturing spaces in multiple LEED projects in Colombia and Venezula. In those cases though, there was a ridge vent in addition to the side wall louvered openings. This works as a stack event and air comes in the sides and is exhausted out the top. These can even be mechanical exhaust fans for not too much cost. When the fans were passive and not mechanical, we had to provide documentation of an engineered natural ventilation system showing how the air would move through the space and how that was more than enough air than required by ASRHAE.
Thanks for your comments,
If I could use Section 22.214.171.124. of ASHRAE 62.-2010 I would be able to comply with natural ventilation. Can I use 2010 version instead of section 6.4 - ASHRAE 62.1-2007?
"126.96.36.199. Double side openings. For spaces with operable openings on two opposite sides of the space, the maximum distance from the operable openings is 5H, where H is the ceiling height"
I am currently trying to calculated Ds for the cooling condition for a project I an working on. Initially, I had the Ds value for each dual fan duct duct VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. unit set to 100%, but I was told by a colleague to change the value of Ds to be Ds = the minimum cooling flowrate of VAV/ the maximum cooling flowrate (Vdzd) of VAV.
For example a room in the building has a max supply cfm of 210 and a minimum supply cfm of 63. Should Ds then be: Ds=63/210 = 30%? Or should I leave Ds as 100%?
When I switched Ds from 100% to the equation I got the critical zone needs more ventialation error message.
A direct answer to your question is: set Ds = minimum flow (30%).
I had a technical advice by the reviewer before to perform the calculations at the worst-case conditions, which was (in my case) to set most VAVs at Ds of 30%, and few VAVs that where designed with Ds of 40% (and I justified that by a narrative).
Also the worst-case case is generally during heating mode, for me, I like to check both; heating and cooling modes.
I am trying to determine whether or not I am calculating Ds correctly. I previously had every zone set to 100% Ds, but I was told that Ds = the minimum supply air flowrate/maximum supply air flowrate. For example we are using dual fan dual duct VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. units and the maximum cooling cfm for a room is 210 cfm and the minimum is 63 cfm. Should Ds then be:
Ds = 63/210 = 30%? Or should I just have Ds set to 100%?
When I had all the values to Ds set to 100% the sheet worked, but when I changed it to the equation I got the error message Critical zone needs more ventilation. Any help would be greatly appreciated.
Thank you for your time,
Sorry for the multiple posts, the website was experiencing problems for maintenance.
I'm a little confused by what we are supposed to show to document compliance for non-occupiable spaces, like restrooms, that the space matrix call out as "N (VRP) / Y (other req's).
We have filled out the VRP calculator for all the spaces and have ventilation thru 100% DOAS serving all the spaces with radiant panels for heating. However, the LEED reviewer is questioning our square footage because the SF in the VRP Calculator is less than the total project square footage because the non-occupiable spaces are not included, since the space matrix said not to include them in the VRP Calcs.
We have enough exhaust in these spaces to comply with ASHRAE 62.1, but what does LEED want us to show for these spaces to prove compliance? Does checking the box that says, "The project meets Sections 4 through 7 of ASHRAE Standard 62.1-2007, Ventilation for Acceptable Indoor Air
Quality." qualify us as stating that we meet the ventilation rates for these spaces or do we need to prove it further to LEED?
Should we just submit a floor plan with the non-occupiable zones highlighted and with square footages shown or do we need to submit some kind of offline spreadsheet for these zones?
I always upload a sheet showing every space type that is not included in the VRP calc and the associated areas. Some are exhaust only, some are non-occupiable, and some are not applicable such as chase space and shafts. If you add it all up then you should be somewhere around 90% of the gross area from PIf3.
I think this credit is for fresh air requirement.
Is there any requirement for Exhaust rates, are they need to documented for this credit
Our project have store rooms as per local Fire and safety compliance no electrical circuits and equipment's are allowed to this rooms
so can we exclude this kind of spaces from VRP calculation
VRP calculation is for Occupied area or all areas (Toilet, Storerooms)
The VRP calculation is for occupiable spaces. However, the credit applies to all requirements of ASHRAE 62.1 - 2007, including exhaust rates.
Has anyone been successful using the alternative compliance path and submitting their own ASHRAE 62.1 calculation/spreadsheets in lieu of using the built in LEED or 62MZCalc form?
We would rather save time by not re-entering a ton of info and just provide a narrative and our calcs to prove we meet ASHRAE 62.1.
While we have not submitted our own EQp1 calculations in lieu of the 62MZ we have been told by GBCI that non-62MZ calculations are acceptable.
As always, provide a detailed narrative explaining your methodology.
I think that it is unlikely that the LEED reviewer will accept your own spreadsheet. They provide a spreadsheet for you to use. I think it would take longer for you to convince them that you calculated multiple zones with unused OA correctly than it would to just fill out their spreadsheet. I recommend using the provided 62MZcalc.
We have a project that is natural ventilated in perimeter spaces (circulations and cafe dining rooms), and It is mechanical ventilated in core spaces (meeting rooms and cafe dining room) that is pursuing LEED for NC 2009.
Our mechanical designer is wondering if the source of supply outdoor air can be an indoor natural ventilated space. What I mean is that we can locate the supply duct for the injector fan near to the operable window in the indoors?
Any help, please?
LEED AP BD+C
No, you cannot. The fresh air needs to come from outside.
Do you any experience with the v2009v4_Minimum IAQIndoor air quality: The quality and attributes of indoor air affecting the health and comfort building occupants. IAQ encompasses available fresh air, contaminant levels, acoustics and noise levels, lighting quality, and other factors. Performance Calculator_v02 spreadsheet found under Credit Resources for IEQp1? Is this form suitable for showing compliance with Multiple Zone Systems in lieu of ASHRAE 62MZ calc spreadsheet?
Additionally, we are confused by some of the parameters when using the Appendix A method for VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. systems. When there is no secondary recirculation, shouldn't Er and Ep be "1"? However, the definition of Ep is given as Vpz / Vdz, in which case Vpz = Ds * Vdz for VAV systems representing minimum flow conditions. Therefore, shouldn't Ep be equivalent to Ds?
We recently had the opportunity to get some feedback from a USGBC reviewer on the new spreadsheet. Yes, this is the preferred calculator, instead of the older ASHRAE 62mz excel sheet and the template. This appears to be what they want to see going forward as it is better organized and the results tab makes it easier to review.
Note one item we found which is that on the SINGLE ZONE tab, the default occupancy isn't populating correctly. It pulls numbers from the wrong place. So you need to use manually entered occupancies. Apparently this is a known error and they are working on fixing it and re-releasing it.
I'll default to some of the more technical experts on the second part of your question.
Yes, the single zone tab does not populate correctly. Additionally, the summary tab fails to display all input systems in our case. We contacted the GBCI about this and they said that they did not know of this mistake before and that it is probably due to the fact we have gone back and forth in inputting multiple zone and %100 OA systems. So be careful when using this spreadsheet.
My project is outside of the US.Can't i use the spreadsheet?
We have three Warehouse's that use 'turbo ventilators' (wind driven extraction fans) and not a pure mechanical system. The warehouses also do not have enough enough openings to meet the natural ventilation requirements of 5.1 in ASHRAE 62.1.
To meet the requirements of IEQp1 I feel my only option is to motivate that the this is an 'Engineered natural ventilation system' as per the exception to 5.1 in ASHRAE 62.1. In the wording (and confirmed in CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide ID#2539);
'An engineered natural ventilation system when approved by the authority having jurisdiction need not meet the requirements of Sections 5.1.1 and 5.1.2. '
South African building codes don't deal with turbo ventilators directly, and because warehouses do not have a minimum ventilation requirement here the designs/drawings were approved by the authority having jurisdiction (AHJ).
The issue is they would definitely be approved by AHJ because there is no minimum requirement.
But this is like simply using a less stringent code, which is not the intent.
How can I show compliance with IEQp1 for these areas?
Does the cut-sheet show estimated cfm under normal conditions? Then, you might be able to complete the calculator and meet the minimum requirement.
We have used these types of systems in Colombia in similar warehouse applications. The walls also had louvers on them for intake. We provided basically an engineered natural ventilation analysis to show the projected air flow through the spaces, and compare it to the required amount by ASHRAE. Usually these systems, especially if there are openings on the side, bring in more than enough outdoor air.
Thanks for the responses. Sorry I took so long to reply.
Gustavo yes the cut-sheets show estimated cfm. But this is of course at an assumed wind speed over the roof.
Joseph was this approach accepted?
So in summary my approach would be to provide analysis that shows the ASHRAE 62.1 requirements are met rather than approved by AHJ because there is no requirement here.
I'm now working on a project under LEED NC certification.
The ground floor includes a conference room, offices, technical spaces, meeting rooms, and one big space, in which the following functions are located without any physical separations:
- Two lobbies with reception desk
- Corridors and circulation
- Break area
The above-mentioned big space is served by 2 AHUs (which serve also other rooms).
We pursue the verification according to ASHRAE 62.1:2007 and I'd like to understand which kind of space use we have to verify for this big space.
Can we separate in different singles functional units, even if these are not physically separated?
I would separate it into different spaces based on use. Upload a floor plan showing how the spaces are separated and what the area of each space is.
I am currently working on a project which has a design requirement on air side system and water side system. When I tried to enter the details into the LEED online form, I got some confusion which I am listing out here. I require your suggestion or support to make my understanding clear to fill the form. The project is located in Dubai.
The HVAC scheme is that, there are ERU’s, DX units, AHU’s, FCU’s in this project and the scheme is ERU’s will supply the fresh air after energy recovered from the return air. This fresh air will be supplied to all the AHU’s and FCU’s catering different part of the building. While I fill the IEQ P1 form, I came across a number of questions which are listed below.
1. Is it enough to provide the details of ERU’s only in the form or I need to input each and every FCU’S and AHU’S in the form. I believe, I need to input all the FCU’s and AHU’s in the form after categorising them into Single zone and multiple zone units.
2. I believe, single zone system is a system serving a single zone only. Multiple zone system is a system which serves a group of zones.
3. In my project, we have single zone and multiple zone FCU’s and AHU’s. while I enter the IEQ P1, I need to check the single zone and multi zone tick box and enter the details of single zone and multi zone units as required irrespective FCU’s or AHU’s. Am I correct?
4. Those with multi zone AHU’s and FCU’s, the return air is taken back to the AHU’s and FCU’s respectively which will get mixed with the fresh air and will be supplied to each zone. I believe this cannot be considered as a local recirculation units and is not a fan power box unit. So there is no need to use 62MZCalc sheet. I can fill the details of these systems/units directly into the IEQ P1 LEED online sheet in the table provided for MULTIPLE ZONE SYSTEM under Appendix for VRP calculator i.e. Table IEQp1-A1 and Table IEQp1 – A2.
5. Space matric for IEQ says, spaces like electrical and mechanical rooms, restrooms and bathrooms are excluded. Is it ok to exclude these rooms from the IEQ P1 online sheet too i.e. excluding these rooms in the form?
1.You have to provide a calculation per each outdoor injection fan (either AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition)
2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork., ERU...). If this fan serves one single zone (i.e. room) the reviewers are asking to use the online form. Otherwise, use the offline calculator and upload it. You will have to add up the supply air for all the FCU in every zone and the numbers should be consistent with the mechanical schedule.
3.See comment #1
4.There are two critical numbers in the calculator: i. outdoor air entering the building (not return), and ii. Supply air (sum of airflow provided by all the FCU in the zone)
5.I would rather check the definition of "occupiable space: an enclosed space intended for human activities, excluding those spaces intended primarily for other purposes, such as storage rooms and equipment rooms, that are only occupied occasionally and for short periods of time." (verbatim from INTERPRETATION IC 62.1-2007-16).
Many Thanks Gustavo.
1. Is it ok to use the Online form itself for Multi zone units or it is mandatory to use the 62MZCALC for these Multi zone units?
2. Electro - Mechanical rooms are not regularly occupied rooms so I can leave these rooms from entering it into the Online form correct?
1.The reviewers we have dealt with have always asked us to upload the offline calculator.
2.Imho I think electro-mechanical rooms fall under "equipment rooms" category and according to the interpretation IC 62.1-2007-16 they are exempt from ventilation. Keep in mind that some utility providers recommend installing louvered doors, which I think is a best practice to prevent moisture from accumulating in the room.
If a space is ventilated through an exhaust fan (rate according VRP) and a permanently open vent to the outdoors, can this space be considered mechanically ventilated, 100%OA and can use an Ez of 0,8 if exhaust fan is in the opposite side of the room of the vent?
According to Table 6-2, the above would be correct.
Thank you Andrew for the quick answer. I had this doubt because from some previous comments seemed that outdoor air should be provided by a supply system in order to consider the zone as mechanically ventilated.
1.Is the project allowed to have operable windows instead of permanently opened vents? Air would infiltrate through cracks and doors.
2.The project will not be capable of providing MERV13 filters. Is the project still eligible to pursue credit IEQc5?
1. No, unless they are interlocked to automatically open when the fan is on.
1.Is this requirement based in a LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. or addenda? This would be very helpful in order to explain the client.
Hi, my project has PAU to supply OA through VAVs to AHUs, which then supply air to office spaces. This PAU also supplies OA through CAVs to lift lobbies and FCUs recirculate the air there. I plan to submit offline calculator 62MZ calc on LEEDonline. I see "it is acceptable to provide value only for critical zone" and "the critical zone is the zone requires the largest fraction of OA in the primary air stream". So I want to ask that I just need calc OA in office only in the calculator and can neglect the lift lobby?
Thank you very much
I have a question about a project under LEED certification.
We are designing the ventilation of one floor below-grade parking garage, situated below an open area adjacent to an office building.
The garage floor plan is of rectangular shape.
There are no Full Time Equivalent in the parking garage (guard stations, and/or other occupied/occupiable spaces are not located in the garage, so the whole space is only for the purpose of parking and circulation).
There is no mechanical ventilation. Openings for natural ventilation are provided.
We would like to understand whether our design can be considered an alternative compliance path to ensure indoor air quality compliant with "Minimum Exhaust Rate" Table 6-4 of ASHRAE 62.1:2007 Note C " Exhaust not required if two or more sides comprise walls that are at least 50% open to outside".
Openings for natural ventilation are evenly distributed on the roof of the garage (grade level). The overall surface of these openings to the outside is greater than 50% of the overall surface of two side walls.
Also, an electronic CO monitoring system provides an alarm if the threshold of CO concentration achieves/exceeds 25ppm. As a result of an alarm, access to other vehicles to the garage is temporarily impeded until dilution/exhaust of contaminant through natural ventilation lowers CO concentration below the threshold.
Can we implement such a compliance path in lieu of mechanical ventilation?
Hi Fabio, unfortunately, your design does not comply with the requirements of ASHRAE 62.1. The reason that they specify two sides with more than 50% rather than 25% wall area, is because they count on crosswinds ventilating the space. You should add the mechanical ventilation.
Also, in my opinion, relying on buoyancy of CO vs air to ventilate the space is not a good design practice. The level of CO may rise to unsafe levels and it is unlikely that the people going in to get their cars will decide to wait it out. If that case were to happen during a busy period, I could not imagine an owner who would prefer a closed garage in lieu of having simply installed the mechanical ventilation in the first place.
Thank you so much!
A quick question.
Are we allowed to submit our own calculation spreadsheets of ASHRAE 62.1 or we have to use LEED provided forms to apply for this credit?
You will need to use the credit form or the 62MZ calculation spreadsheet found in credit resources.
I am filing out the LEED documentation for IAQc1 for a RecA Renewable Energy Certificate (REC) is a certificate representing proof that a given unit of electricity was generated from a renewable energy source such as solar or wind. These certificates are able to be sold, traded, or bartered as environmental commodities, where an electricity consumer can buy the renewable energy attributes of electricty to support renewable energy, even if they are consuming generic grid-supplied electricity that may be supplied by nonrenewable sources. Center in St. Louis, MO. There is a Natatorium in this Rec with attached Locker/restroom/shower spaces. We are exhausting these space per 62.1 Table 4. How do I document these space for LEED? Is simply showing the EA calculations per 62.1 are correct enough or do I actually need to include these space in my "Minimum IAQ Performance Calculator" (from LEED)?
I am using LEED v2009.
I am conducting a ventilation calculation for the an office building that consists of open office space, conference rooms, corridors, etc. The office space is served by 4-pipe fan coil (terminal) units. 100% outdoor air provided from a central outdoor air unit is ducted to the return duct of each fan coil unit.
One of my zones (i.e. group of spaces serve by a since fan coil unit) consists of a 700 SF conference room and an adjacent 100 SF corridor.
The conference room has 10 chairs, so at 0.06 CFM/SF and 5 CFM/person, we get about 92 CFM OA. The air distribution effectiveness is 0.8, so the OA requirement is 115 OA CFM.
The 100 SF corridor in this zone has very little internal load - it is an internal space and only a lighting load. The 0.06 CFM/SF required by code, along with its distribution effectiveness of 0.8, requires 7.5 CFM of OA be delivered to this space.
However, since the 7.5 CFM of OA is nearly half of the primary airflow required to cool the space (as calculated by Carrier Hourly Analysis), we're getting a System Ventilation Efficiency as low as 0.20, which is driving up the OA required to the fan coil unit to a point that it is greater than the supply air requirement to cool the zone. For a zone that requires only 400 CFM of 55F supply air for cooling, the OA calculation is requiring (115 CFM + 7.5 CFM)/0.20 = 612.5 CFM of OA. The ASHRAE 62.1 Calc is increasing the supply air to this zone such that it is 100% OA and it is overcooling the space, which requires reheat. This is detrimental to the buildings energy performance because the increase OA conditioning load and zone reheat are unnecessary.
I understand that I can manually change airflow in HAP and alter the model in other ways to get a more logical answer, but I am really looking for a LEED interpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. towards whether or not this small corridor (an other small spaces that require OA by ASHRAE 62.1) really need to be included in the OA calculation in such a situation. My firm would like to use our energy modeling software to calculate loads and OA requirements for buildings, but this specific instance is preventing us from doing so.
Please let me know if you have any knowledge as to whether these small spaces requiring OA can be excluded/altered from the IEQp1 Calculation in any way. Any help in a resolution is much appreciated. Thanks!
LEED reviewers will definitely expect you to ventilate the corridor properly. Some options for you include:
- increase the supply air to the corridor
-if the corridor is in the building interior and does not need heat, then you could design it without reheat. This would allow you to use an air distribution effectiveness of 1.0. That should help a little bit.
-you could install a transfer fan from another room to the corridor. Just note that your calculation would have to be based on "unused outdoor air".
I hope that helps!
We have a project that has two cold rooms at -17 and 0 degrees Fahrenheit. These rooms are temporary storage locations of perishable product.
They will be regularly occupied but only for short shifts (around half an hour).
These cold rooms (as with most cold rooms) do not have a fresh air supply to them. It would not be practical to supply fresh air to them, as this would result in huge energy uses and a much more expensive system. The rooms are very large, will frequently have doors opened and closed, and are only occupied by a few occupants
I can find no reference anywhere in ASHRAE 62.1 regarding cold rooms.
Is there anyway in which I can exclude these rooms from the requirements of ASHRAE 62.1 for IEQp1?
I can find no other interpretation result speaking to this.
Also the cold rooms are acceptable according to the local code.
We are about to submit a similar project for LEED certification.
We are not providing any fresh air to cold rooms and freezers. Will let you know about the outcome as I exactly have the same question.
Good morning everyone. I have three quick questions I am hoping someone can help me with;
Many of my zones have fresh air supplied by a central AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition)
2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork. and also have an FCU within them recirculating the air. So the Design total supply for each zone (Vdzd) is large and therefore the Design primary supply (Vpsd) for the multizone system is much higher than that capable from the AHU alone. I'm concerned that the reviewer will check this high value of Vpsd against the unit on the equipment schedule and think something is amiss. However the Outdoor air intake (OA) is lower than the flow rate listed on the equipment schedule in all cases. Should I clarify the high Vpsd in someway, or will it be clear to the reviewer that it is because of the FCUs? Perhaps I am worrying about nothing?
Am I correct in saying any zone that is listed in Table 6.4 does not need to meet minimum supply rates defined in previous sections, and conversely that any zone not in table 6.4 does not need to meet minimum exhaust rates of table 6.4. In my user generated spreadsheet each zone is in one or the other section, but not both. Is this correct?
I have a cold room in the facility that does not have a fresh air supply to it because this would require a huge amount of energy and a much bigger refrigeration system. The workers in this area will only be in there for short shifts and the space is very large. Is it excluded from the minimum supply requirements?
Thanks very much
I'm wondering if the kitchen MUA unit needs to included in the ventilation calculations? We would like to exclude it from our calcs because it’s primary purpose is for space pressure control, not ventilation. The KMAU will only run when the exhaust hood is on and all of the outside air will be exhausted quickly. The required ventilation air for the kitchen is supplied by an adjacent RTU.
Commercial kitchens are included in Table 6-4. You do not need to include them in the 62MZ calc, but you should address them in a narrative to state that they meet the requirements of the standard.
I wanna ask this related to your answer: Can we classify the kitchens and kitchenettes in an office building as commercial kitchens? Office kitchens are neither residential kitchens nor food service facility kitchens as given in the IEQ Space Matrix. Therefore, we exclude them from VRP calculation, but justify the minimum exhaust requirements as per Table 6-4 in a separate narrative. Is this the correct approach? Thanks.
I am working on a project that has a 45,000 SF unconditioned warehouse and utilizes natural ventilation. A small portion of the warehouse is used for educational purposes, the majority is used for storage. Currently, the only operable windows are along the perimeter walls, however the majority of the space is not within 25 feet of these operable windows. The ceiling is 40 feet high.
How would we comply with natural ventilation requirements in the central spaces? If operable skylights are added, the floor space would still be outside the 25 foot range. Is there an exemption for the portion of the warehouse that is used only for storage?
I am afraid that if you are not able to provide natural ventilation meeting ASHRAE or CIBSE requirements you will need to implement mechanical ventilation. I would say you have to options:
1.I would try first with ASHRAE 62.1-2010, which gives you the requirements to design a space with cross ventilation (unlike ASHRAE 62.1-2007)
2.If you are not able to provide natural ventilation following (1) I would try with mixed-mode ventilation. As far as I know ASHRAE hasn't defined the requirements for this system yet, but it has been widely accepted and very efficient. According to ASHRAE 62.1 you need to provide 0 L/s•person PLUS 0.3 L/s•m2.
Thank you for the response. I just came across a LEED Intepretation, #10144 that states "if the distance from windows or openings is more than 25 feet, is there an exhaust air fan located at the furthest distance from the windows that is inducing the outdoor air to flow through the space; is that exhaust fan flow equivalent to the outside airflow that would be required for the space if the Ventilation Rate Procedure were used?" If utilizing exhaust fans in spaces that are greater than 25 feet from operable windows, is there a requirement for the distribution of exhaust fans throughout the space that doesn't comply?
It depends on your floor plan. You will need to ensure that there are left no zones without ventilation (either rooms or corners in your warehouse).
Hello in a Museum, we have an uderground open space, that, on our understanding is an exterior space, as it is outside the Access vestibule. It has a roof overhang but have a completely and permanently open side, with more than 40ft and the total height of the space, in which there are the acces stairs and a water feature. However there will be two people in this space working in an info booth. In our undesrtangind, this is an exterior space with the shadow of the overhang, and therefore have no thermal conditioning or mechanical ventilation. Is this space is required to be included in the Ventilacion calculations of the ASHRAE Standard 62.1 (Natural or mechanical) and in the Thermal comfort requirements (ASHRAE Std. 55). We thing it's excluded as an outdoor space, but want to confirm.
According to your explanation, I would say that the info-booth can be considered as naturally ventilated (assuming they have a large open window) and it meets ASHRAE 62.1-2007 standard.
Regarding ASHRAE 55 requirements, unless the info-booth has some kind of heating or air conditioning I think it is difficult to justify thermal comfort in this space (and achieve IEQc7.1). However, you might have a chance if the energy model says this space is within the confort range most of the year.
Hi, I just received the feedback from reviewer. We have AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition)
2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork. to supply 100% OA to the space and FCUs for secondary recirculation. Reviewer said:
"The design system primary supply air flow volume (Vps) don't match the supply air flow of AHU in equipment schedule. + Calculation must be performed at the worst-case condition when VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. system is at minimum flow."
I'm try to figure out where is the error in my calc. I'm checking Vdzd, Ds, Vpz, Vps. For example, Vdzd = 1,400 (OA /SA by AHU) + 10,000 (recirculated by FCU) = 11,400 cfm. How can I adjust (Ds). I had set Ds = 100% beforehand. I think that had made supply airflow by AHU was much larger than that in equipment schedule. And I just check that Vdzd * Ds = Vpz (supply airflow by AHU) = 1,400 cfm. So is it correct that I adjust Ds = 1,400/11,400 = 12%
Principal, Director of Sustainability
Westlake Reed Leskosky
Mechanical and natural ventilation designs must comply with requirements to mitigate environmental tobacco smoke.
The amount of fresh air the HVAC system is designed to process has a direct correlation to the buildup of carbon dioxide.
Increasing the ventilation rates 30% above the ASHRAE standard will help teams gain IEQp1.
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