This credit encourages project teams to reduce the amount of mercury used in building lighting. When building management controls all lamp purchases, the credit is readily achievable, while multi-tenant buildings with decentralized purchasing will find it more challenging.
Remember that the mercury content of each individual lamp does not need to meet the credit threshold of 70 picograms per lumen1. A lumen is a unit of luminous flux equal to the light emitted in a unit solid angle by a uniform point source of 1 candle intensity.
2. A measurement of light output. hour. Your team needs to meet this target on average for all lamps purchased during the performance period. This provides teams with some flexibility in selecting lamps.
Teams should use the USGBC calculator to track and document lamp purchases. Updating the calculator as lamps are ordered can help you confirm that, on average, your purchases during the performance period are meeting the 70 picograms per lumen hour target.
No. Lamp purchases made for the entire building must be included in your tracking, including orders placed by tenants. That said, you’re allowed to exempt up to 10% of the building floor area if the tenants that use that space are not willing or able to share information about lamp purchases.
You must purchase at least one lamp during the performance period to achieve this credit.
To establish and maintain a toxic material source reduction program to reduce the amount of mercury brought onto the building site through purchases of lamps.
Implement the lighting purchasing plan that specifies an overall building average of 70 picograms of mercury per lumen1. A lumen is a unit of luminous flux equal to the light emitted in a unit solid angle by a uniform point source of 1 candle intensity.
2. A measurement of light output.-hour or less for all mercury-containing lamps purchased for the building and associated grounds within the project boundary. Include lamps for both indoor and outdoor fixtures, as well as both hard-wired and portable fixtures. Lamps containing no mercury may be counted only if their energy efficiency at least equals that of their mercury-containing counterparts.
Complete documentation for achievement of MRc - Purchasing - lamps on the LEED v4 O+M:EB Platinum StopWaste.org headquarters office building at 1537 Webster Street, Oakland, CA. Project documentation was shared with LEEDuser through cooperation with that organization, and the LEED consultant, BuildingWise LLC
These samples show what data to look for on a product sheet and how to calculate contributing value to earning purchasing credits.
USGBC released a revised Purchasing Calculator with an updated weighted average formula for lamps. The link to the calculator in the Resources tab will take you to the updated version.
The LEED guideline states that “Mercury-free lamps, such as LEDs, can be included in the pictogram per lumen1. A lumen is a unit of luminous flux equal to the light emitted in a unit solid angle by a uniform point source of 1 candle intensity.
2. A measurement of light output.-hour calculations only if their energy efficiency levels are equal to or greater than those of comparable mercury-containing lamps.”
Our understanding is that all LEDs have no mercury content, how can the LEDs be included in the pictogram calculations, in order to achieve this credit?
Karim, they would be counted as having zero mercury content.
And how can we prove that the energy efficiency levels of LED are equal to or greater than those of comparable mercury-containing lamps?
There are several ways that this could be done. Below are a few ideas.
1) Find documentation from the manufacturer that speaks to the energy efficiency of the lamp as compared to the alternatives.
2) Show that the LED lamp has replaced a different lamp in the building with a higher wattage
3) Show that the lumens per watt for the LED lamp is lower than the lumens per watt for mercury containing lamp that would be used for the same application.
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