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 62.1-2004 (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, are somewhat different and you may need to follow both paths for the same building. Naturally ventilated spaces must follow the distinct methodology for natural ventilation defined by ASHRAE 62.1, paragraph 5.1, even if other spaces in the same building are mechanically ventilated and are following the methodology defined by ASHRAE 62.1, section 4 through 7 (for spaces with both mechanical and natural ventilation, or just mechanical ventilation).
New construction additions will need to confirm that any ventilation systems serving the project meet the ventilation rates required by ASHRAE 62.1-2004, 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 modify the base building system or provide detailed analysis documenting the constraints and explaining why the base building systems cannot be upgraded.
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 EQc2: 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: 2005 (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 62.1-2004, or local codes if they are more stringent. Since ASHRAE 62.1-2004 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 62.1-2004 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.
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 create a more effective natural ventilation design. If the data is used early in the design to help inform team on such thing as space planning and building envelope design. An airflow modeling professional may add some upfront costs, while likely improving system efficiency and effectiveness.
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 62.1-2004 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 62.1-2004 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 62.1-2004. 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 62.1-2004. 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 62.1-2004 minimum.
For naturally ventilated spaces, confirm compliance with the requirements of ASHRAE 62.1-2004 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 submittal template 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 for New Construction and Major Renovations Version 2.2
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.
Meet the minimum requirements of Sections 4 through 7 of ASHRAE 62.1-2004, Ventilation for Acceptable Indoor Air Quality. Mechanical ventilation systems shall be designed using the Ventilation Rate Procedure or the applicable local code, whichever is more stringent.
Naturally ventilated buildings shall comply with ASHRAE 62.1-2004, paragraph 5.1.
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 health. Use the ASHRAE 62 Users Manual for detailed guidance on meeting the referenced requirements.
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.
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 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.
This template is the flattened, public version of the dynamic template for this credit that is used within LEED-Online v2 by registered project teams. This and other public versions of LEED credit templates come from the USGBC website, and are posted on LEEDuser with USGBC's permission. You'll need to fill out the live version of this template on LEED Online to document this credit.
Documentation for this credit can be part of a Design Phase submittal.
I see that on Table E2. there are exhaust requirements for the living room, kitchen and baths of a residential units, but what about supply OA air requirements? When I go to table 6-1 the is a ventilation requirement for bedroom and living room but it's not clear if its only applicable to hotel, motels, resorts, etc. Please note that our project is a multifamily complex with 72 residential units with living, dining, bedroom, kitchen, bathroom and balcony.
Im a bit confused in regards to providing OA to a trash/recycle area and teledata area. What classification do they fall under in Ashrae 62.1 2004? Additionally, in our design they are being air conditioned by minisplits with no OA due to the fact that they are not regularly occupied. How should we approach this credit?
I need some help and advice regarding the LEED EQP1 response to the reviewer’s comments.
It is unclear how the percentage of design airflow at the condition analyzed (Ds) was determined for the project. The system level and ventilation zone values are reported as 1.0, which is unexpected for a variable volume system.
Provide additional information regarding the selection of Ds, revise the model, as necessary, to be consistent with the flow conditions for the worst case conditions analyzed (most likely heating mode), and confirm that the value for Ds is correct both at the zone level and at the system level. Note that if the weighted average value for Ds at the zone level is 0.3, the system level value would also be anticipated to be 0.3.
The reviewer’s comment regards using the correct values for Ds.
Ds is the percentage of total design airflow at condition analyzed. It appears that the reviewer’s comment assumed the use of a percentage less than 100% (or really a fraction less than 1.0) for the winter season when the air flow is less due to less need for cooling. The way our calculations are done is for a separate winter and summer spread sheet to show the outside air requirements, supply air, percentage of outside air, and Ds (percentage of supply air to maximum supply air). For example for 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.-A-1, COOLING EXCEL SPREAD SHEET 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.-A-16
COOLING 735 CFM, 155 CFM OUTSIDE AIR (AHU VALUES 979 CFM O.A., 5,100 SUPPLY AIR. THIS GIVES O.A./S.A. = 0.19)
Ds = 1.0 since VAV-A-16 supplies 100% of the 735 cfm for cooling.
HEATING 275 CFM, 155 CFM OUTSIDE AIR (AHU VALUES 979 CFM O.A., 1,855 SUPPLY AIR. THIS GIVES O.A./S.A. = 0.53)
Ds = 1.0 since VAV-A-16 supplies 100% of the 275 cfm for heating.
As you can see, the outside air does not change.
The reviewer may not have known this and thought that the Ds for heating should be 275/735 = 0.37.
However, our calcs have 979/979 = Ds of 1.0 for summer cooling and 275/275 = Ds of 1.0 for winter heating
Does the following explanation address this comment sufficiently?
Each zone’s outside air rates were calculated for both summer (cooling) and winter (heating). This provided a different supply air quantity which was lower in the winter season. Also, the ratio of outside air to supply air was higher in the winter so that the requirements for outside air based on ASHRAE 62-99 are satisfied when the supply air quantities vary. The value for Ds of 1.0 for summer relates to the summer supply cfm. The value for Ds of 1.0 for winter relates to the winter supply air which is usually lower. Therefore, the Ds of 1.0 is reflective of the supply air cfm for that season.
Would they allow me to upload ASHRAE 62MZCalculator 2007 instead of the 2004 version?
It's ok to use the 2007 version, but be clear to the reviewer that you are using this version in its entirety.
hi, please help me regarding this issue......
Project have DCV in some areas. Does, these areas should be included in the IEQp1 62MZ or in VRP calculations??. Project team fulfill the Min. OA requirement for other spaces which don't have DCV. There is only one rooftop unit.
All areas should be included in the VRP calculations.
I am doing a project which is a office bldg. The system of the bldg is 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. with VSD for each conditioned zone. There is no MZ system. I submitted the fresh air calculation as per 62.1 for review.
Now reviewer has given a technical advice which is stated below-:
If the air distribution is through 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, then the fresh air calculation shall be based on Critical Zone (where Zp is high) at worst case condition (i.e. occupancy is at peak and heat gain is minimum – eg: meeting room in a winter season).
Kindly suggest me how to perform same?
From my perceptive--------
As you mentioned there is no MZ, u may perform calc as per single zone units but be sure that single zone should satisfy the defination of single zone given in ASHRAE 62.1. apart from it, the value for Ez depend upon flow velocity, location of diffuser, cool air etc. given in 62.1, take appro. value of Ez from that table.
lastly, if u r performing calc for single zone thus no question arise regarding the value of Zp or Ev, since these values required only for MZ calc.
A major renovation project was completed in 2008, and they have been in the building for 4 years. In working to certify the project it was realized that EQp1 was not met in the design. The owner is considering paying to have the system upgraded to meet the requirements. Can we still meet the requirements of this credit if they've been in the building for 4 years before the credit was met?
It is unfortunate that the building was under ventilated for 4 years, however, LEED will be interested in the final/current design of the building. Submitting how the building will be ventilated from now on should be acceptable.
This project is a small, seasonally used facility. It is only in operation when the doors are open, and relies completely on natural ventilation when in operation. In terms of operable window/wall area and square footage, the facility meets the natural ventilation requirements. My question concerns section 4 of ASHRAE 62.1 2004 on regional and local air quality, and the subsequent documentation. In terms of regional air quality, the EPA has deemed my location as non-attainment for NAAQS for many years now. For local air quality, the conditions are relatively unfavorable with a very close highway and wind direction. My concern is that the project will not meet the intent of the prerequisite because of the quality of air being used for all ventilation. However, there are buildings in my area that have been certified and also use natural ventilation. It is stated that I must document section 4 of ASHRAE 62.1 2004, yet in all of my searching have yet to see anybody mention it. Is the documentation of regional and local air quality a required submittal for this prerequisite? Is it possible to meet the requirements of this prerequisite even if the regional and local air quality is undesirable?
Hopefully this response isn't too late to no longer be useful to you. Section 4 does not require you to address unacceptable regional and local air quality, but simply to investigate and document it. Treatment is addressed in Section 6.2.1 for the Ventilation Rate Procedure, but is only required for "each ventilation system that provides outdoor air through a supply fan", which does not seem to be the case with your project. Therefore, investigation and documentation should be sufficient for the purposes of EQp1.
Your inclinations are correct; most projects do not address Section 4 in their EQp1 documentation and it is not required. However, the Reference Guide does require a design narrative describing the project's ventilation design, including specific information regarding fresh air intake volumes and any special conditions that affected the project's ventilation design. Unacceptable regional and local air quality would be one of those special conditions that should be mentioned in this narrative.
I am reviewing IEQp1 kitchen that feeds outside air from an 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. for 100% outside air. The AHU also conditioned only for this sector. The question is this: Due to having no return, What will be the efficiency Ez in the area?.
Good question. Although you are not returning the air back to the supply unit, the air has to go somewhere. In your case, the air is probably exhausting through ceiling kitchen fume hoods. In that case you have overhead supply and overhead return. If you are cooling only than Ez-1.0, in heating mode Ez-0.8.
We have a computer server room which has a recirculating heat pumpA type of heating and/or cooling equipment that draws heat into a building from outside and, during the cooling season, ejects heat from the building to the outside. Heat pumps are vapor-compression refrigeration systems whose indoor/outdoor coils are used reversibly as condensers or evaporators, depending on the need for heating or cooling. In the 2003 CBECS, specific information was collected on whether the heat pump system was a packaged unit, residential-type split system, or individual room heat pump, and whether the heat pump was air source, ground source, or water source. for cooling but does not have any outside air ventilation (by design). The LEED Reviewer commented "computer rooms that are occupied at least once daily for more than 15 minutes at a time are generally considerd regulary occupied spacesOccupied Spaces are defined as enclosed spaces that can accommodate human activities. Occupied spaces are further classified as regularly occupied or non-regularly occupied spaces based on the duration of the occupancy, individual or multi-occupant based on the quantity of occupants, and densely or non-densely occupied spaces based upon the concentration of occupants in the space.". Does anyone know where this time frame for occupancy come from or dealt with this requirement before?
LEEDUser defines 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. as an hour per day. I believe they get that definition from the Reference Guide.
We are working on a residential building with mechanically ventilated corridors and naturally ventilated dwelling units. Our approach for the mechanically ventilated portions was accepted, but we were denied this prerequisite based on our documentation for natural ventilation. We provided window-to-floor area calculations demonstrating compliance and calculations for naturally engineered cfm for the spaces that are not within 25 feet of operable windows. The LEED Reviewer denied us this credit based on the following, "However, no calculations have been provided to document that these spaces comply with the natural ventilation requirements … Please note that one of the two following calculations would be necessary to document compliance with ASHRAE 62.1 for the dwelling units with occupiable space that is more than twenty-five feet from the windows:
1. The project team may apply the VRP procedure only, rather than pursue any portion of the natural ventilation path, and supply ventilation air through the undercut door. The entire unit space and occupancy must be included and it would not matter if spaces were farther than 25 ft. from operable openings.
2. If submitting for engineered natural ventilation, demonstrate means of continuously delivering or inducing ventilation air to spaces outside 25 ft. (for example continuously operating exhaust/transfer fans) during the occupied periods."
This does not seem in line with our previous LEED reviews that have accepted naturally engineered ventilation induced from intermittent kitchen/bathroom exhaust and pressurized corridors. Has anyone else run into this problem or guidance for documentation moving forward?
We have actually seen this in the past, but it has come as a surprise to many project teams. We've found that building code officials may approve rooms as naturally ventilated even if only a part of that room is within 25' of an operable window, whereas LEED reviewers have interpreted the ASHRAE 62.1 standard more strictly and excluded areas beyond 25' as naturally ventilated.
In some situations you might be able to show a room gets sufficient ventilation with bathroom exhaust and pressurized corridors, but you'll need detailed calculations to show that.
In one project we faced the choice of doing complex modeling of airflow or installing booster fans to provide additional air circulation to a partially enclosed sleeping area toward the back of a "loft" unit. We installed the fan.
Interesting to note that LEED Homes for Midrise doesn't allow make-up air for units to come from a shared corridor, and I've heard rumors that future versions of 62.1 may require a more thorough provision of outside air.
I am filling out a table similar to Table 1 in EQp1 to demonstrate our project's compliance with ASHRAE 62.1 -2004. I am realizing that our actual population numbers are different than what would be generated from the default occupant density. I am understanding from Note 4 in Table 6-1 of ASHRAE 62.1 - 2004 that I am allowed to use the actual population numbers instead of the default occupant density numbers. Is this correct?
Dave, this is correct. It's helpful to provide a narrative of how the actual population numbers are determined. Using seat count based on furniture plans is usually the most common approach.
We are going to setup a Cold Chain Facility (A Multipurpose Cold Storage) which is having
1. 5 Nos of cold chambers with total capacity of 2500 MT designed for a temperature range of 0 deg to 4 deg C to suit the requirement of variety of products.
2. 6 Nos. Deep Freeze Chambers each of 250 MT, 1 chambers of 500MT & 5 chambers of 100 MT. each thus totaling capacity of 2500 MT designed for storage of frozen foods at a temperature range of (-18) to (-)22 deg C.
3. 1 No. 1 No. Pre-cooling chamber of 5MT Capacity to Pre-cool the Fruits & Vegetables from 30 to 35 deg C to 2 Deg C in 6 hrs.
4)4 Nos. ripening chambers for uniform ripening of bananas, 10 MT each chamber.
5)It will have mechanized stacking arrangement, Ante Room, Loading / Unloading dock, Process hall, machine room, offices and toilets.
6)Other facilities like DG Sets, Water based fire fighting system, weighing machines and strapping machines are also included.
My question is whether cold storage facility (details mentioned above) has the possibility to get the LEED Certification? If yes which rating system will be applicable and please inform us the cold storage project which has certified earlier.
Your reply at the earliest will be highly appreciable.
We were able to achieve a LEED rating for two refrigerated warehouses. Each project included freezers and separate refrgierated spaces, similar to what you mention above. One was the Anheuser Busch refrigerated facility, the other, Gourmet Guru, a food distributor. Both achieved a rating using NC version 2.2.
On a past LEED project, Version 2.2, it was interpreted that the refrigerated warehouse spaces (deemed a process load due to the nature ofthe facility), required ventilation because there were people working there throughout the day. Their main tasks were loading/unloading only, so it's doubtful that any one person spent a significant amount of time in the space itself.
Has anyone challenged the ventialtion requirement or was this original interpretation incorrect? What was the outcome? Given the delicate nature of maintaing low temperatures and a quality product, it seems that this process load should have been exempt from the 62.1 and 90.1 requirements. It should be noted that assocaited spaces within the warehouse such as offices, did meet the requirements of 62.1 and 90.1.
Lorey, I've asked around and was unable to get help on these questions. Have you learned anything more?
Tristan, I was able to get two refrigerated warehouse facilities approved by USGBC without including ventilation in the storage space. These were both V2.2 projects.
A project having a corridor 34.4m long has an operable window (operable size 1.5m x 0.55m) at both ends; the project is naturally ventilated and must comply with ASHRAE 62.1 section 5.1. Does the corridor has to meet the 8m from the operable area requirement of the mentioned standard even if the window is from end to end? Thanks
What do you mean by "the window is from end to end"? Trying to understand the question... thanks!
Can we use the gross area of an operable window (say 5.5' x 2.0') which can only be opened up to 30 degrees in the computation of natural ventilation compliance calculation? Or should we only use the effective opening since the window can't be fully opened?
Katherine, you can still assume the gross open area (in a vertical plane) for the calculation. Separate from ASHRAE 62 compliance, when a designer looks to calculate effective airflow, a correction factor is used based on the window type.
Just a follow up question, can an integrated door (say window is 2.835m x 2.25m w/ integrated door 0.90m x 2.25m) be considered as opening to satisfy requirement for naturally ventilated areas?
Katherine, if the door is intended to be open as part of the natural ventilation, I don't see why not. I wouldn't count it, though, if it won't actually be open for this purpose.
I am finishing up the requirements for LEED NC and am inqiring as to whether CO2Carbon dioxide sensors are required to meet this prerequisite? My Commissioning Agent feels it is a requirement and my HVAC contractor who has done several LEED projects said this has never been a requirment for V 2.2. I know it is a requirment for EQ c1, however, we are goig for that credit. Please calrify?
CO2Carbon dioxide sensors are not a requirement to meet IEQp1. I am not sure why your commissioning agent thinks that—do they give a reason?
The only other reason I can think of why the Cx1. Commissioning (Cx) is the process of verifying and documenting that a building and all of its systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the owner's project requirements.
2. The process of checking the performance of a building against the owner's goals during design, construction, and occupancy. At a minimum, mechanical and electrical equipment are tested, although much more extensive testing may also be included. agent is looking for CO2Carbon dioxide sensors is a requirement in Chapter 6 of ASHRAE Standard 90.1-2004/2007 that CO2 sensors be provided for spaces with occupant density greater than 25 sf/person (with some exceptions and other conditions). This goes beyond LEED and pure code compliance, depending on where the project is located.
Will using boiler or plant steam for humidification cause IEQp1 to be denied?
Kath, could you elaborate on your concern? Humidification is used for facilities all over the country. In New York City, major museums actually inject Con Edison steam directly into the airstream for humidification, even though there have been concerns about the impact of some of the water treatment chemical used on artwork. Are you wondering if you need to provide a clean steam-to-steam generator for humidification or about the use of humidification in general?
Thanks, Roger. . We were told (hearsay) that USGBC is following an ASHRAE 62.1 guideline paragraph that states water for humidifiers shall be potable and therefore they rejected a project that used plant steam. See below.
IEQp1 “Minimum Indoor Air Quality Performance” has a primary focus of confirming that minimum outside air flow requirements are met in accordance with ASHRAE 62.1-2007 “Ventilation for Acceptable Indoor Air Quality” In addition IEQp1 requires compliance with this standard, sections 4 through 7. One paragraph within these sections is:
Paragraph 5.13.1 Water Quality for humidifiers “Water shall originate directly from a potable source or from a source with equal or better water quality”.
Kath, thanks for the clarification. I think in this situation, you probably do want to use a clean steam-to-steam generator to avoid issues with ASHRAE 62.1 compliance. Thanks for bringing up this question in the first place!
I have a factory project, including sewing plant and warehouse for storage.
In sewing plant we use HVAC system and in warehouse we keep natural ventilation.
So, the question here is:
For sewing plant we will apply section 4-7 of ASHRAE 62.1
For warehouse we will apply paragraph 5.1 ASHRAE 62.1.
Is it right?
Since I saw in LEED template online, we just select 1 option either MEchanical or Natural.
Fabio, it sounds like you have the right approach. As we discuss above in the Bird's Eye View, both cases may be needed in the same building. Perhaps there is a way to do an alternative compliance path, and select both options.
We have a major renovation project and in a portion of the buidling we will be replacing rooftop units, but would like to re-use the existing ductwork. Is this allowed and how does it affect or not affect the compliance with 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?
I don't see any reason this would not be allowed. Did you have any specific concerns in mind?
Credit compliance is based on ventilation rate calculations, which I don't think would be affected, as long as you know what you're working with in the building.
In respect to ASHRAE 62.1, the values tabulated from air intakes (TABLE 5-1) have to be measured in horizontal or vertical?
Afonso, the distances should be measured as a straight line from intake to exhaust, rather than horizontal or vertical alone.
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 EQp1.
Mechanical and natural ventilation designs must comply with requirements to mitigate environmental tobacco smoke.
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