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LEED EQ - Indoor Environmental Quality

LEED EQ Gives Guidance On Reducing Pollutants Within Our Home Living Environment

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Americans spend an inordinate amount of time indoors, as much as 90%. Since indoor air pollutants can be 2 to 5 times higher than the indoors, and sometimes as much as 100 times addressing the issue of indoor air pollution comes to the forefront. As many as 17 million Americans can suffer from asthma and 40 million suffer from some sort of allergy, which contributes to millions of work and school days missed.

Over the past 20 years there has been much research and study done as to the cause and effect of indoor air pollution on our health. It has been determined that it is much easier to address this issue on the front end of construction of a home rather than depend on measures to solve already existing problems. There are generally three types of strategies: source removal, source control, and dilution.

Source removal involves the evaluation and selection of materials that harbor offensive and unhealthy compounds and the release of these compounds through outgassing (VOC's). Besides selection of materials with low VOC's, the project team can schedule the delivery of materials to the site and sequence construction to allow the major portion of outgassing to take place prior to home occupation.

Source control involved the capturing of pollutants that are known to existing in the home. An example of this would be the HVAC system of the home. Protection of the system during construction and building flushout prior to occupancy reduces the potential for problems.

Dilution is a process where fresh outdoor air is used to ventilate the home and to flush indoor air pollutants to the outside through mechanical methods. Typical air handling systems in homes just recirculate the indoor air rather than exhausting the air.

Of coarse the ultimate indoor environmental quality is the comfort of the home's occupants. This can be attained through means of automatic sensors and controls to maintain proper temperature, humidity and ventilation. The points in LEED EQ encourage the building/design team to provide a much healthier indoor air environment in the homes they build and give the home occupants greater comfort in doing so.

There are two parallel pathways through the 10 EQ credits in the LEED for homes Rating System.

Pathway One:

Projects that participate in the US EPA ENERGY STAR with Indoor Air Package (IAP) automatically gain 13 points. Projects that gain points through IAP are not eligible for EQ 2-10, because IAP has a similar path. A maximum of 8 additional points can be attained from:

    LEED EQ 5.2: Enhanced Local Exhaust
    LEED EQ 5.3: Third Party Testing
    LEED EQ 7.2 or 7.3: Better or Best Air Filters
    LEED EQ 8.2: Indoor Contaminant Control
Pathway Two:

This pathway also has a total maximum point gain of (21), distributed throughout EQ credits 2 - 10.

Total Points Available (21)

LEED EQ Points Required (6)

  • EQ 1
  • EQ 2
  • EQ 3
  • EQ 4
  • EQ 5
  • EQ 6
  • EQ 7
  • EQ 8
  • EQ 9
  • EQ 10
ENERGY STAR with Indoor Air Package: LEED EQ 1 Intent:

Improve the overall quality of a home's indoor environment by installing an approved bundle of air quality measures.

Prerequisites:

None

Credits: ENERGY STAR with Indoor Air Package (13 points) LEED EQ 1 Overview:

The US EPA ENERGY STAR with Indoor Air Package (IAP) is a labeling program which is designed to deliver a cleaner, healthier indoor air quality for new homes. When implemented, a home can gain 13 LEED credits for controlling source removal, source control and dilution.

A project receiving points for this credit may skip the prerequisites in EQ 2-10 and is not eligible to earn points in EQ 2.2, 3, 4.3 6, 8.1 9, and 10.

Achieving the measures in EQP's Indoor Air Package may qualify a home to receive points in other categories of the LEED for Homes Rating System. Hover HERE to see table.

Approach:
    EPA's ENERGY STAR with Indoor Air Package (IAP) is not available in all parts of the country. Since Energy Raters typically are responsible for inspections, check with your Energy Rater is the program is available in your part of the country.
    Review both pathway and determine with is the best path for your project to take.
    Indoor Air Package measure should be defined as early in the design process of the project as possible, to incorporate measures into the final design.
Calculations:

None

Exemplary Performance:

None

Verification and Submittals:

Builder/Project Team: Present ENERGY STAR with Indoor Air Package certification to the Green Rater.

Green Rater: Verify that the ENERGY STAR with Indoor Air Package certification has been achieved.

Resources:
    USGBC Website
    US EPA ENERGY STAR Indoor Air Package: US EPA
Synergies and Trade-Offs:

A project receiving points for this credit may skip the prerequisites in EQ 2-10 and is not eligible to earn points in EQ 2.2, 3, 4.3, 6, 8.1, 8.3, 9, and 10.

Achieving the measures in EQP's Indoor Air Package may qualify a home to receive points in other categories of the LEED for Homes Rating System. Hover HERE to see Table of Equivalencies.

Applicability of ENERGY STAR Indoor Air Package Measures Table
LEED for Homes prerequisites/credits Relevant Indoor Air Package measures Applicability
Innovation & Design Process 2.1, 2.2 Various Meeting Indoor Air package specifications will address many durability issues listed in durability inspection checklist template.
Sustainable Sites 5 3.1-3.4 Depending on project location, meeting Indoor Air Package specifications may earn up to 2 LEED points
Energy & Atmosphere 6.1 4.1, 7.4 Meeting Indoor Air Package specifications achieves prerequisites EA 6.1 (a) and 6.1 (c).
Materials & Resources 2.2 6.3-6.9 Depending on project details, meeting Indoor Air Package specifications may earn up to 2 LEED points.
Combustion Venting: LEED EQ 2 Intent:

Minimize the leakage of combustion gasses into occupied spaces of the home.

Prerequisites: Back-Draft Basic Combustion Venting Measures: (Prerequisite) LEED EQ 2.1

Meet all the following requirements:

No unvented combustion appliances are allowed.

A carbon monoxide (CO) monitor must be installed on each floor.

All fireplaces and wood stoves must have doors.

Space and water heating equipment that involves combustion must meet one of the following. Space heating systems in homes located in IECC-2007 climate zone 1 or 2 are exempt.

    it must be designed and installed with closed combustion (i.e. sealed supply air and exhaust ducting);
    it must be designed and installed with power-vented exhaust: or
    it must be located in a detached utility building or open-air facility.
Credits: Enhanced Combustion Venting Measures: (2 points max) LEED EQ 2.2

Install no fireplace or wood-stove, or design and install a fireplace or wood-stove according to the requirements of this Table Hover HERE to see Combustion-Venting requirements Table.

Conducting a Back-Draft Potential Test:

Use the results from a blower-door text, measure the pressure difference created by the presence of a chimney-vented appliance. To ensure a limited risk of back-drafting, the pressure difference must be less than or equal to 5 Pascals, where:

Total P = (Q/C) 1/n (must be <= 5 Pascals)
and Q is equal to the sum of the rated exhaust provided by the two biggest exhaust appliances in the home, and C and n are both constants produced by the blower-door test results.

Overview: LEED EQ 2.1
    The prerequisite serves to minimize the leakage of toxic combustion gasses into the indoor air environment.
    Strive to provide closed combustion through direct and power venting sources.
    The best way to avoid pollutants from entering the home from fireplaces or wood-stoves is to avoid installing them.
    Utilize carbon monoxide monitors to minimize the risk of this deadly gas.
Overview: LEED EQ 2.2
    Complying with LEED EQ 2.1 and eliminating fireplace and wood-stove appliances is the best way to ensure indoor air quality. However my meeting the appliance portion of LEED EQ 2.1 provides minimum protection from back drafts.
    It is much better to provide improved appliances that ensure a more complete burn thereby reducing potential gas risks to the home occupants.
    Best practice provides improved appliance efficiency and the highest level of back-draft protection.
Approach: LEED EQ 2.1
    Select fireplaces and wood-stoves that are well vented and have tight-fitting doors.
    Install Carbon Monoxide Detectors on each level of the home.
    Work with HVAC contractor to select the best quality devices available.
    Avoid installation of chimney vented furnace the location of a water heater in the attic or attached garage.
    Closed combustion requires that both the supply air and the exhaust air are fully ducted and sealed.
    Use power vented appliances where ever possible.
    Select a high-energy efficient furnace 90% AFUE and direct vent to outside.
    Avoid mid-range efficiency furnaces as they vent into conventional draft chimneys and do not meet this standard.
    Search for a power venting appliance that is quiet.
Approach: LEED EQ 2.2
    The only way to eliminate harmful combustion gasses is not to install the appliance.
    The next-best option is to install a device that burns cleanly and minimizes the risk of back-drafting into the interior of the home.
    Look at natural gas and propane appliances. They often have direct venting and pose little risk.
    Open hearth fireplaces are not eligible for this credit because of their inefficiency due to the fact they draw their combustion air from the home's interior. Consequently they tend to pull air through envelope leaks, making the home drafty.
    If a traditional wood-burning fireplace is installed, select one that is UL-Listed or a factory-built insert that meets EPA standards for particulate matter emissions.
    Fireplaces with 60 -80% efficiency ratings are available on the market.
    Minimize the use of large exhaust fans during fireplace or wood-stove operations as this can cause backdraft problems.
    Seal air leaks at the joint between the chimney and the wall by removing the trim and applying heat-resistant caulking.
Calculations: LEED EQ 2.1

None

Calculations: LEED EQ 2.2

To meet best practice requirement and earn 2 points, a home with a wood-burning stove or fireplace must pass a back-draft potential test, to be conducted by an energy rater. Use the formula and calculation as listed in the Back Draft Test above.

Exemplary Performance:

None

Verification and Submittals:

Building/Project Team: LEED EQ 2.2: Present any fireplace or stove equipment literature o the Green Rater for visual inspection. Include fireplace or stove equipment literature in the occupant's operation and maintenance manual. For best practice with a wood-burning stove or fireplace, present back-draft calculations to the Green Rater

Green Rater: LEED EQ 2.1: Visually verify that all requirements of the prerequisite have been met.

Green Rater: LEED EQ 2.2: Visually verify that all applicable standards and certifications have been met: check safety listing in the appliance user manual, check EQP certification of the EQP website or user manual. For best practices with a wood-burning stove or fireplace, visually verify that back-draft calculations are completed. Visually verify all applicable equipment in the home.

Resources:
    Combustion Gasses and Carbon Monoxide: US EPA
    Environmental Protection Agency
    Hearth, Patio, and Barbecue Association
    Masonry Heater Association of North America
    US EPA ENERGY STAR Indoor Air Package: US EPA
Synergies and Trade-Offs:

A project receiving points for EQ 1 is not eligible to earn points in EQ 2.2. A project pursuing EQ 2.2 must meet all the prerequisites in LEED EQ 2-10.

Fireplace and Stove Combustion-Venting Requirements Table
Fireplace or Stove Better Practice (1 point) Best Practice (2 points)
None See "best practice" Granted automatically
Masonry wood-burning fireplace Install masonry heater as defined by American Society for Testing and Materials Standard E-1602 and International Building Code 2112.1 Meet requirement for "better practice", and conduct back-draft potential test to ensure Tot P <= 5 Pascals (see "Conducting a Back-Draft Potential Test" below)
Factory-built wood burning fireplace Install equipment listed by approved safety testing facility (e.g., UL, CSA, ETL) that either is EPA certified or meets the following: equipment with catalytic combustor must emit less than 4.1 g/hr of particulate matter, and equipment without catalytic combustor must emit less than 7.5 g/hr of particulate matter Meet requirement for " better practice", and conduct back-draft potential test to ensure tot. P<= 5 Pascals(see "Conducting a Back-Draft Potential Test" below).
Woodstove and fireplace insert Install equipment listed by approved safety testing facility that either is EPA certified or meets following requirement: equipment with catalytic combustor must emit less than 4.1 g/hr of particulate matter, and equipment without catalytic combustor must emit less than 7.5 g/hr of particulate matter Meet requirement for" better practice", and conduct back-draft potential test to ensure tot. P<= 5 Pascals (see "Conducting a Back-Draft Potential Test" below).
Natural gas, propane, or alcohol stove Install equipment listed by approved safety testing facility that is power-vented or direct-vented and has permanently fixed glass front or gasketed door. Meet requirement for" better practice", and include electronic (not standing) pilot
Pellet stove Install equipment that is either EPA certified or listed by approved safety testing facility to have met requirements of ASTM E1509-04, "Standard Specification for Room Heaters, Pellet Fuel-Burning Type. Meet requirement for "better practice", and include power venting or direct venting.
Moisture Control LEED EQ 3 Intent:

Control indoor moisture levels to provide comfort, reduce the risk of mold, and increase the durability of the home.

Prerequisites:

None

Credit: Moisture Load Control: (1 point) LEED EQ 3

Install dehumidification equipment with sufficient latent capacity to maintain relative humidity at or below 60%. This must be achieved through one of the following:

Additional dehumidification system(s).

A central HVAC system equipped with additional controls to operate in dehumidification mode.

Note: LEED for Home does not encourage active dehumidification for all projects. Work with the HVAC contractor to determine whether this credit is appropriate and/or necessary.

Overview:

Humidity levels that in inordinately high or low can cause durability problems in home. High humidity can foster mold growth and can lead to human health issues. Low humidity levels can cause extreme wood shrinkage and health problems for home occupants as well.

Approach:
    Control of high humidity is especially important in warm weather climate regions, where dehumidification may be required. On the other hand humidification is usually only required in colder regions, where dryness from forced air furnaces or hydronic heating can lead to severe dry conditions.
    Ideal humidity levels can be difficult to determine because thermal comfort for individuals is affected by air temperature, humidity level, air movement and personal preference or health conditions. Ideal humidity levels are usually somewhere between 25% and 40% in the winter and below 60% in the summer.
    This credit can only be earned through the use of dehumidification controls on the HVAC equipment that ill maintain humidity levels at or below 60% RH. Certain dry climate regions may never reach this level and therefore this credit will not apply.
    Use an engineer and HVAC contractor to figure infiltration rates and ventilation rates to calculate the amount of moisture to be removed in the summer and added in the winter.
    Avoid the over-sizing of AC units as these systems will not properly dehumidify the space.
    Simple controls can be very effective. In cold climates for example, use a dehumidistat on an exhaust fan, and in warm, humid climates, use a thermostat that also has a humidity control allowing the AC unit to operate for either cooling or dehumidification.
    Mechanical ventilation systems should be sized appropriately to help ensure proper moisture control.
    For guidance on the appropriate humidity levels necessary for thermal comfort.
    Hover HERE to see Humidity Comfort Table
Calculations:

Use an engineer and HVAC contractor to figure infiltration rates and ventilation rates to calculate the amount of moisture to be removed in the summer and added in the winter. Even the best and most accurate calculations will not guarantee adequate moisture control for all circumstances.

Exemplary Performance:

None

Verification and Submittals:

Trade: Provide any equipment literature to builder or project/team.

Building/Project Team; Present calculations of latent capacity to the Green Rater. Include dehumidification equipment literature in the occupants operations and maintenance manual.

Green Rater: Visually verify that all calculations related to latent capacity are completed. Visually verify all applicable equipment in the home.

Resources:
    Building America Best Practice
    ENERGY STAR Program: Dehumidifiers
    Energy and Environmental Building Association, Builders' Guides
    Moisture: Built to Keep it Out of Homes in Warm, Humid Climates
    Mold Resources: EPA
    Residential Dehumidification Systems Research for Hot-Humid Climates US Department of Energy, Building America Program
Synergies and Trade-Offs:

A project receiving points for EQ 1 is not eligible to earn points in EQ 2.2. A project pursuing EQ 2.2 must meet all the prerequisites in EQ 2-10.

Water leakage through the building envelope can cause mold and other indoor environmental problems. Improved foundation, exterior walls, and roof water management should be addressed in the durability inspection checklist (LEED ID 2)

In hot and humid climates, dehumidification can reduce the energy demands associated with air-conditioning. (EA 1,6).

Maximum Comfortable Humidity at Summer Temperatures
Indoor Temperature (degrees F) Relative Humidity (%) Humidity Ratio (lb water / lb dry air)
70 76 0.012
74 66 0.012
78 58 0.012
82 50 0.012
Outdoor Air Ventilation: LEED EQ 4 Intent:

Reduce occupant exposure to indoor pollutants by increasing ventilation with outdoor air.

Prerequisites: Basic Outdoor Air Ventilation: (Prerequisite) LEED EQ 4.1

Design and install a whole building ventilation system that complies with ASHRAE Standard 62.2-2007. A summary of alternative is provided below, by the HVAC contractor should review and follow the requirements of ASHRAE Standard 62.2-2007, Sections 4 and 7.

    Mild climate exemption: A home built in a climate with fewer than 4,500 infiltration degree-days is exempt from this prerequisite.
    Continuous ventilation: Meet the ventilation requirements in the following table:
    Hover HERE to see Continuous Ventilation Table.
    Intermittent ventilation: Use Equation 4.2 of ASHRAE Standard 62.2-2007 to demonstrate adequate ventilation air flow.
    Passive ventilation: Have a passive ventilation system approved and verified by a licensed HVAC engineer as providing ventilation equivalent to that achieved by continuous ventilation systems as described the the following table: Hover HERE to see Continuous Ventilation Table.
Credits: Enhanced Outdoor Air Ventilation (2 points) LEED EQ 4.2

Meet one of the following:

In mild climates (fewer than 4,500 infiltration degree-days), install a whole-building active ventilation system that complies with ASHRAE Standard 62.2-2007.

-OR-

Install a system that provides heat transfer between the incoming outdoor air stream and the exhaust air stream, such as a heat-recovery system must be listed by a certified testing lab. (e. e., UL, ETL).

Third Party Performance Testing (1 point) LEED EQ 4.3

Have a third-party test the flow rate of air brought into the home, and verify that the requirements of ASHRAE Standard 62.2-2007 are met. In exhaust-only ventilation systems, install exhaust ducts according to Table 7.1 ASHRAE Standard 62.2-2007, and either test the flow rate out of the home or conduct air flow tests to ensure back-pressure on <= 0.20 inches w.c.

Overview: LEED EQ 4.1, LEED EQ 4.3
    In the past, plenty of fresh air came into homes through leaks and cracks in doors, windows, joints etc. As technology changed in the homebuilding industry, the home envelope has become much tighter and these infiltration sources no longer exist. Newer homes have had to rely on mechanical ventilation to solve the problem on inadequate outdoor air. Even well-designed mechanical ventilation systems may perform inadequately due to installation errors and equipment failure. Third party testing assures the home occupants that the installed system is properly installed.
Overview: LEED EQ 4.2
    There are two kinds of ventilation enhancement that are appropriate for this credit: Balanced ventilation systems, which provide both supply and exhaust flows at the same time, providing a more balanced and controlled flow of ventilation into the home.
    Heat-transfer ventilators (HRV's) allow incoming ventilation air to be heated or cooled (tempered) reducing the amount of energy required to heat or cool this incoming air. Heat Recovery Ventilators (HRV's) also transfer moisture between outgoing exhaust streams and incoming supply streams which helps moderate moisture levels in the home.
Approach: LEED EQ 4.1, LEED EQ 4.3
    Having a whole home ventilation system is important in all regions of the country.
    Relying solely on natural ventilation does not address ventilation concerns when the home doors and windows are completely shut. This approach is only attainable in mild climates.
    Homes in areas with fewer than 4,500 infiltration degree-days are exempt from the prerequisite.
    ASHRAE Standard 62.2-2007 addresses minimum ventilation capacity. Additional capacity may be required if there will be high occupant loads or additional indoor pollutants from a home office, crafts or other activities.
    The HVAC contractor should follow the requirements of ASHRAE Standard 62.2, Section 4.1.3, to ensure that natural and mechanical ventilation is properly integrated and the house has neither too little nor too much ventilation.
    The minimum air-flow requirements listed in the the following table are applicable only to systems designed for continuous operation. Hover HERE for table.
    Take a careful look at the location of the intake air grille. Do not locate near vehicle exhaust, or other appliance exhaust vents.
Approach: LEED EQ 4.1:

Mandatory measures can be met with one of these three basic strategies:

    Exhaust Only Ventilation: Install a quiet bathroom fan with a switch for extended running time. This fan serves to depressurize the home and this method is suitable only for cold weather climate homes as in the warm climate, warm, humid air is drawn in through leaks. Supply Only Ventilation: Install a fresh air duct from the exterior and tie it into the return air side of the HVAC system. This method is best suited for hot climates.
    Balanced System With or Without Recovery: Install a system of supply and exhaust fans that operate simultaneously to ensure an exchange of air between inside and outside. Use energy recovery units to use waste energy from exhaust fans to preheat the ventilated air in winter and pre-cool it in the summer.
Approach LEED EQ 4.2
    Have the HVAC contractor install an HRV or ERV system that is listed by a certified third-party laboratory from the list that Home Ventilation Institute maintains.
    Size the HRV or ERV properly for the whole-house ventilation system.
    Projects in mild climates (fewer than 4,500 infiltration degree-days) can earn this point by simply putting in a ventilation system, although it still may be of value to install one of these systems in a mild climate.
    Heat Recovery is not an option if the LEED EQ 4.1 requirement is met with passive, exhaust-only or supply-only ventilation designs.
Calculations: LEED EQ 4.1, LEED EQ 4.3

ASHRAE prescribes a simple calculation for determining the minimum amount of mechanical ventilation. See Equations 4.1a and 4.1b in Standard 62.2, Section 4 of ASHRAE.

Calculations: LEED EQ 4.2

None

Exemplary Performance:

None

Verification and Submittals:

Trade: LEED EQ 4.1: For EQ 4.1 b and c, provide calculation to builder or project team leader demonstrating the ventilation system is designed to meet the requirements. Fo LEED EQ 4.1 b, c, and d, sign an Accountability Form to indicate the system is installed according to the design specifications. Deliver any ventilation equipment literature to builder or project team leader.

Builder/Project Team: LEED EQ 4.1: For LEED EQ 4.1 b and c, present calculations to Green Rater demonstrating that the ventilation system is design to meet the requirements. Include equipment literature in the occupant's operations and maintenance manual.

Green Rater LEED EQ 4.1: For LEED EQ 4.1 b and c, visually verify that all calculations related to outdoor air ventilation are completed. For LEED EQ 41 b, c, and d, verify that an Accountability Form has been signed by the responsible party. For LEED EQ 4.3, test the outdoor ventilation air floor into the home and verify that it meet the requirements.

Resources:
    USGBC Website
    American Society of Heating, Refrigerating and Air-Conditioning Engineers
    ASHRAE Standard 62.2-2007
Synergies and Trade-Offs:

A project receiving points for EQ 1 is not eligible to earn points for EQ 4.3, but may earn points for EQ 4.2. A project pursuing EQ 4.3 must meet all the prerequisites in LEED EQ 2-10.

Natural air leakage through the envelope contributes to the overall ventilation rate of the home (LEED EQ 3.1-3.3). From a health perspective, it is important not to under ventilate a home. From an energy perspective, it is important not to over ventilate.

Exhaust fans, which also provide the local exhaust required by EQ 5.1, can simultaneously provide the outdoor air ventilation system for the home.

A heat-recovery system can substantially reduce the energy used by the heating and cooling equipment EQ 6.

Minimum Air Flow Requirements For Cont. Ventilation
Conditioned Floor Area70 Bedrooms
0, 1 2, 3 4, 5 6, 7 >7
<= 1,500 30 45 60 75 90
1,501 - 3,000 45 60 75 90 105
3,001 - 4,500 60 75 90 105 120
4,501 - 6,000 75 90 105 120 135
6,001 - 7,500 90 105 120 135 150
> 7,500 105 120 135 150 165
Local Exhaust: LEED EQ 5 Intent:

Reduce moisture and exposure to indoor pollutants in kitchens and bathrooms.

Prerequisites: Basic Local Exhaust: (Prerequisite) LEED 5.1

Meet all the following requirements:

    Design and install local exhaust systems in all bathrooms and half-bathrooms and the kitchen to meet the requirements of Section 5 of ASHRAE Standard 62.2-2007. Sample requirement that relate to minimum intermittent local exhaust flow rates are shown in this table.
    Hover HERE to see Minimum Air Flow Requirements for Intermittent Local Exhaust Table
    Design and install the fans and ducts to meet the requirements of Section 7 of ASHRAE Standard 62.2-2007.
    Exhaust air to the outdoors (i.e. exhaust to attics or interstitial spaces is not permitted)
    Use ENERGY STAR labeled bathroom exhaust fans (except for exhaust fans serving multiple bathrooms).
Credits: Enhanced Local Exhaust: (1 point) LEED EQ 5.2

Use one of the following strategies in every bathroom to control the use of the local exhaust fan:

    An occupancy sensor.
    An automatic humidistat controller.
    An automatic timer to operate the fan for a timed interval after occupant leaves the room.
    A continuously operating exhaust fan.
Third-Party Performance Testing (1 Point) LEED EQ 5.3

Perform a third-party test of each exhaust air flow rate for compliance with the requirements in Section 5 of ASHRAE Standard 62.2-2007.

Overview:

Through this credit a home is exhausted of pollutants from the 2 most moisture producing rooms, the kitchen and bathrooms. Since it is most effective to exhaust pollutants at their source, it is recommended to place exhaust fans or exhaust grilled directly in all kitchen and bathroom spaces. It is also recommended that these fans be controlled with occupancy sensors to guarantee operation during periods of occupancy and shut down where there is no activity. Since there can be installation errors, mechanical problems and incidental damage to these systems, third-party inspection and performance testing is required for LEED EQ 5.3.

Approach:
    Work with your electrician to ensure that kitchens and bathrooms have exhaust systems with minimum air flow, as listed in the Table.
    Hover HERE to see Minimum Air Flow Requirements for Intermittent Local Exhaust Table
    Specify the use of ENERGY STAR labeled bathroom fans that are sized properly for the intended exhaust use.
    Since there are no ENERGY STAR rated kitchen fans, size the range fan for that function. Avoid sizing the range fan larger that 200 cfm, otherwise it runs the risk of depressurizing the home and causing a back-draft situation.
    Have the HVAC contract size the duct runs as straight as possible. Also be careful not to undersize duct runs.
    Be sure to specify this measure in both the electrical and HVAC portion of the plans to avoid confusion.
    Best practice indicates to use fans with a sound rating o 1 sone or less
    Specify timers and occupancy sensors to ensure fans are only in use during occupied times.
Calculations:

Use the following equation to determine the total kitchen air changes per hour provided by the kitchen fan: ACH(kitchen) =m Fan Capacity x 60 Minutes / Kitchen Size, where ACH is air changes per hour, fan capacity is measured in cfm, and kitchen size is measured in cubic feet. IF ACH(kitchen) is less than 5, install the kitchen fan as a ventilated range hood.

Exemplary Performance:

None

Verification and Submittals:

Trade: LEED EQ 5.1: Provide calculations to the builder or project team leader demonstrating that the local exhaust system is designed to meet the requirements. Sign an Accountability Form to indicate that the local exhaust system is installed according to the design specifications. Provide any equipment literature to the builder or team leader. LEED EQ 5.2: Provide any equipment literature to the builder or team leader.

Builder/Team Leader: LEED EQ 5.1: Present calculations to the Green Rater demonstrating that the local exhaust system is designed to meet the requirements. Included any equipment literature in the occupant's operations and maintenance manual. LEED EQ 5.2: Include equipment literature on occupancy sensors, automatic humidistat controllers, automatic timers, or continuously operating exhaust fans in the occupant's operations and maintenance manual.

Green Rater: LEED EQ 5.1: Visually verify that all calculations for local exhaust are completed. Verify that an Accountability Form has been signed by the responsible party. Visually verify all applicable equipment in the home. LEED 5.2: Visually verify all applicable equipment in the home. LEED EQ 5.3: Test exhaust air flow from the home and verify that it meets the requirements.

Resources:
    ASHRAE Standard 62.2-2007
    ENERGY STAR Program, Ventilating Fans: US EPA
    Review of Residential Ventilation Technologies: Building Science.com
Synergies and Trade-Offs:

A project receiving points for EQ 1 is eligible to earn points for EQ 5.2 and 5.3.

If designed properly, exhaust fans can also proceed sufficient outdoor air ventilation system for the entire home, as require by LEED EQ 4.1.

Minimum Air Flow Requirements for Local Exhaust
Location Minimum Air Flow
Kitchen 100 cfm; vented range hood required if exhaust fan flow rate is less than 5 kitchen air changes per hour.
Bathroom 50 cfm
Distribution of Space Heating and Cooling: LEED EQ 6 Intent:

Provide appropriate distribution of space heating and cooling in the home to improve thermal comfort and energy performance.

Path 1: Forced Air Systems: Prerequisites: Room-By-Room Load Calculations: (Prerequisite) LEED EQ 6.1

Perform design calculations (using ACCA Manuals J and Dj, the ASHRAE Handbook of Fundamentals, or and equivalent computation procedure) and install ducts accordingly.

Credits: Return Air Flow or Room-by Room Controls: (1 Point) LEED EQ 6.2
    Ensure that every room (except baths, kitchens, closets, pantries, and laundry rooms) has adequate return air flow through the use of multiple returns, transfer grilles, or jump ducts. Meet one of the following requirements.
    Size the opening to 1 square inch per cfm of supply (this area may include free area undercut below door)
    Demonstrate that the pressure differential between closed rooms and adjacent spaces with return is no greater than 2.5 Pa (0.01 inch w.c.).
Third-Party Performance Test: (2 points) LEED EQ 6.3

Have the total supply air flow rates in each room tested using a flow hood with doors closed or one of the other acceptable methods cited by the ACCA Quality Installation Specifications. Supply air flow rates must be within +/- 15% (or +/- 10 cfm) of calculated values from ACCA Manual J (as required by EA 6.1)

Path 2: Non-ducted HVAC Systems (e.g., Hydronic Systems): Prerequisites: Room-by-Room Load Calculations: (Prerequisite) LEED EQ 6.1

Perform design calculations (using ACCA Manual J and D, the ASHRAE Handbook of Fundamentals, or an equivalent computation procedure) and install system accordingly.

Credits: Room-by-Room Controls: (1 point) LEED EQ 6.2

Design the HVAC system with flow control valves on every radiator.

Multiple Zones: (2 points) LEED EQ 6.3

Install non-ducted HVAC system with at least two distinct zones with independent thermostat controls.

Overview:
    Proper distribution of heating and cooling is expected by today's home buyers. When spaces are perceived as too hot or too cold the occupant simply adjusts the thermostat o their desired comfort range which can result in system inefficiencies. Adequate return air flow is critical in the management of conditioned air to spaces. Inefficient return air flow can result in back-pressure, leading to insufficient air flow into the room and excess air distribution to other rooms.
    Third party testing can identify problems with the design and installation of the distribution system. Ducts can be blocked, crushed or punctured by other trades during construction and third-party testing can resolve these problems.
    Flow controls and zoning with separate thermostatic controls can ensure thermal comfort and save energy in homes with hydronic heating.
Approach:
    Heat loss and heat gain calculations should be performed by the HVAC contractor or energy rater, taking into account wall and ceiling insulation values, air tightness estimates, and window solar heat gain values.
    All forced air heating and cooling systems should be sized in accordance with local winter and summer design data, as found in ASHRAE or ACCA manuals. Do not use rule-of-thumb or worst case scenarios in sizing the equipment as this will result in oversized systems.
    install balancing dampers at each branch system to allow for adjustment and balancing of air flows throughout the system.
    Use properly sized systems with oversized blower capacity to allow for "pick-up" loads - getting the home up to temperature rather than over-sizing the system. Also consider a two-stage air-handling system to provide this ability.
    Consider the use of a hot water air handler rather than a conventional furnace as hot water coils can be sized more adequately.
    Energy Raters should have the proper testing equipment to measure and verify the air flows in each room. The Energy Rater should compare the actual tested results with the calculated in the original design.
    Air-flow testing should be conducted with room damper and register wide open and doors closed.
    Non-ducted systems must also be designed to provide sufficient heating and cooling to each space Use design calculations to determine the proper sizing of radiators in each room.
    Flow-control valves and thermal zoning give the occupant control over temperature settings, which an improve thermal comfort and save energy. Provide instructions on how to use flow-control valves and separate zoning in the occupant's operation manual.
Calculation:

A full detailed ACCA Manual D calculation is strongly recommended by may be more than necessary. Various software programs can assist with HVAC distribution design. Have the HVAC contractor prepare design calculations of software printouts for the Green Raters review.

Exemplary Performance:

None

Verification and Submittals:

Trade: LEED EQ 6.1: Provide system design calculations (e.g., duct sizing worksheet, annotated layout, software printouts) to the project team. Sign an Accountability Form to indicate that the system is installed according to the design specifications. LEED EQ 6.2: For ducted systems, provide calculations to demonstrate that the credit requirements have been met.

Builder/Project Team: LEED EQ 6.1: Present design calculations to the Green rater. Include any equipment literature in the occupant's operations and maintenance manual. LEED EQ 6.2: For ducted systems, provide calculations to the Green Rater demonstrating that the credit requirements have been met.

Green Rater: LEED EQ 6.1: Visually verify that all design calculations are completed. Verify that an Accountability Form has been signed by the responsible party. LEED EQ 6.2: For ducted systems, visually verify that all necessary calculations are completed. For non-ducted systems, visually verify that each room has a flow-control valve. LEED EQ 6.3: For ducted systems, conduct testing of supply air-flow rates in each room and verify that the requirements are met. For non-ducted system, visually verify zones and thermostat controls.

Resources:
    ASHRAE: American Society of Heating, Refrigerating and Air-Conditioning Engineers.
    Air Conditioning Contractors of America: Manual J: Residential Load Calculation
    Air Conditioning Contractors of America: HVAC Quality Installation Specifications
    California Energy Commission: Procedures for HVAC System Design and Installation
Synergies and Trade-Offs

A project receiving points for EQ 1 is not eligible to earn points for EQ 6.2 or 6.3.

A project pursuing EQ 6.2 or 6.3 must meet all the prerequisites in EQ 2-10.

The choice of air filter (LEED EQ 7) should be made prior to duct design, to ensure adequate air flow. Filters with a high MERV can create a large pressure drop that should be accommodated during system design.

Space heating and cooling loads and room air flow rates must be calculated using ACCA Manual J (LEED EQ 6.1). The design calculations conducted for this credit should be based on those Manual J calculations.

Duct installation should be visually inspected during the pre drywall insulation inspection (LEED EA 5).

Air Filtering: LEED EQ 7 Intent:

Reduce particulate matter from the air supply system.

Pathway 1: Forced-Air Systems: Prerequisites: Good Filters: (Prerequisite) LEED EQ 7.1

Install air filters with a minimum efficiency reporting value (MERV) >= 8 and ensure that air handlers an maintain adequate pressure and air flow. Air filter housings must be airtight to prevent bypass or leakage.

Credits: Better Filters (1 Point) LEED EQ 7.2

Install air filters >= MERVE 10 and ensure that air handlers can maintain adequate pressure and air flow. Air filter housings must be air-tight to prevent bypass or leakage.

-OR-

Best Filters (2 points) LEED EQ 7.3

Install air filters >= MERV 13 and ensure that air handlers can maintain adequate pressure and air flow. Air filter housings must be air-tight to prevent bypass or leakage.

Pathway 2: Non-ducted HVAC Systems (e.g., Hydronic Systems): Prerequisites: Good Filters: (Prerequisite) LEED EQ 7.1

Install air filters >= MERV 8 and maintain adequate pressure and air flow in any mechanical ventilation systems. A home in a climate with fewer than 4,500 infiltration degree-days or a home that used only passive or exhaust-only ventilation is exempt from this requirement.

Credits: Better Filters: (1 point) LEED EQ 7.2

Install air filters >= MERV 10 and maintain adequate pressure and air flow for any mechanical ventilation systems.

Best Filters: (2 points) LEED EQ 7.3

Install air filters >= MERV 13 and maintain adequate pressure and air flow for any mechanical ventilation systems.

Overview:
    Inadequate indoor air flow can have negative effects on our human health. By using improved air filtering devices fine particulates and air-borne dust can be removed from our homes atmosphere, thereby reducing risk of asthma allergies and other respiratory illness.
    The industry standard for comparing air filters is Minimum Efficiency Reporting Value or (MERV). This system uses independent testing using ASHRAE Standard 52.2, and they characterize the effectiveness of a mechanical air filter based on the number and size of the particle that can get through the filter under normal conditions.
    The higher the MERV rating, the higher number and finer particulates that are filtered out of the air.
    It is essential that filters be installed properly and air does not by-pass the filtering module.
Approach:
    Work with the HVAC Contractor to choose an air filter that is suitable to the project. Make sure the system is designed with the filter in mind and that the system filtration is selected prior to duct design.
    Make sure you meet the MERV minimum rating of 8.
    True HEPA filters meet the highest standards of MERV and are consider to be MERV 16.
    Since high-efficiency filters restrict air flow, the HVAC systems need to account for this factor in calculations and equipment selection.
    To facilitate proper duct sizing to accommodate high-MERV-rated filters, have the HVAC contractor conduct air-flow measurements with the air filter in place and make sure the filter housing does not leak.
    If the ventilation system is separate from the heating and cooling system, use a separate filter that meets the prerequisite and any credits that are desired.
    Homes in mild climates with infiltration degree-days of less than 4,500 are exempt from the prerequisite.
    Specify filters with a larger surface area to minimize the maintenance of the filters.
    Educate the occupants of the high-efficiency filters and replacement requirements of every 3 to 12 months. Failure to change filters can result in extreme equipment inefficiencies.
    Since MERV filters are more expensive, investigate the use of MERV 8 washable filters. They cost more initially but save a lot of money over the long term.
Calculations:

None

Exemplary Performance:

None

Verification and Submittals:

Trade: Provide and air filter product literature to the builder.

Builder/Project Team: Present any air filter product literature to the Green Rater. Include product literature in the occupant's operations and maintenance manual.

Green Rater: Visually verify that the applicable MERV rating has been met. Visually verify air filters and housings in the home.

Resources:
    Guide to Air Cleaners in the Home: US Environmental Protection Agency
Synergies and Trade-Offs:

A project receiving points for LEED EQ 1 is eligible to earn points for LEED EQ 7.2 or7.3.

The choice of air filter should be made during or prior to duct design (LEED EQ 6) to ensure adequate air flow. Filters with a high MERV can create a large pressure drop that should be accommodated during system design.

Contaminant Control: LEED EQ 8 Intent:

Reduce occupants' and construction workers' exposure to indoor airborne contaminants through source control and removal.

Prerequisites:

None

Credits: Indoor Contaminant Control During Construction: (1 point) LEED EQ 8.1

Upon installation, seal all permanent ducts and vents to minimize contamination during construction. Remove any seals after all phases of construction are completed.

Indoor Contaminant Control (1 point each, max 2 points) LEED EQ 8.2
    Design and install permanent walk-off mats at each entry that are at least 4 feet in length and allow accessibility for cleaning (e.g., grating with catch basin).
    Design a shoe removal and storage space near the primary entryway, separated from living areas. This space may not have wall-to-wall carpeting, and it must be large enough to accommodate a bench and at least tow pairs of shoes per bedroom.
    Install a central vacuum system with exhaust to the outdoors. Ensure that the exhaust is not near any ventilation air intake.
Preoccupancy Flush: (1 point) LEED EQ 8.3
    Flush the home with fresh air, according to the following guidelines:
    Flush prior to occupancy but after all phases of construction are completed.
    Flush the entire home, keeping all interior doors open.
    Flush for 48 hours: the hours may be nonconsecutive, if necessary.
    Keep all windows open and run a fan (e.g., HVC system fan) continuously or flush the home with all HVAC fans and exhaust fans operating continuously at the highest flow rate.
    Use additional fans to circulate air within the home.
    Replace or clean HVAC air filter afterward, as necessary.
Overview: LEED EQ 8.1
    Open ductwork can become clogged with paint, debris, dust and other particulates during construction. This not only is hazardous to the building occupants, it reduces the life of mechanical equipment and damages ducts and other systems.
Overview: LEED EQ 8.2
    Installed walk-off mats can trap contaminants tracked in by our feet on shoes. Such debris as asbestos, pesticides, and other hazardous materials can be trapped by the installation of mats at the entry points of a home. Central vacuum systems exhaust collected dust and particulates to the outdoors, when installed correctly.
Overview LEED EQ 8.3
    Flushing the home expels pollutants from off-gassing VOC's and particulates associated with the construction process. This provides a much safer and healthier home environment for the homes' occupants.
Approach: LEED EQ 8.1
    Require HVAC contractor to tape off any open ducts, registers and grilles, providing a completely sealed system during construction operations.
    Use fans in summer and space heaters in the winter and do not use the installed permanent HVAC system during construction.
    Regularly clean all construction spaces of all dirt and particles and keep a clean work environment.
Approach: LEED EQ 8.2
    First of all encourage occupants and visitors to remove shoes prior to entering the home.
    Make necessary design accommodations to make room for shoe removal and storage.
    Use no carpet in the home foyer or vestibule.
    Design walk-off mats a permanent and meet the aesthetics of the entry and architecture. Make mats at least 4 feet in length.
    Make walk-off mats very accessible for cleaning.
    Mount central vacuum canister in the garage and have an air-tight exhaust to the exterior.
Approach: LEED EQ 8.3
    A pre-occupancy whole-house flush is an easy way to remove volatile pollutants.
    The best approach is to leave the windows open and run all local and whole-house ventilation fans for an extended period.
    An extended flush with windows open may not be practical because of weather or security concerns. Consequently this credit can only be achieved by flushing the house with windows closed for a t least 48 hours. The 48 hours does not have to be consecutive and can be split for instance into 6 hours for 8 days.
    Choose materials with low or no VOC's urea-formaldehyde or other pollutants to reduce the risk of exposure to the occupant.
Calculations:

None

Exemplary Performance:

Projects that implement all three measures in this credit can earn 1 additional point, to be counted under Innovation and Design 3.

Verification and Submittals:

Builder/Project Team: LEED EQ 8.1: Sign an Accountability Form to indicate that the system is installed according to the design specifications. LEED EQ 8.2: Include any filtration system equipment literature in the occupant's operations and maintenance manual. LEED EQ 8.3: Sign an Accountability Form to indicate that the pre-occupancy flush has been conducted according to the requirements.

Green Rater: LEED EQ 8.1: During construction, visually verify that ducts are sealed at termination points. After construction, conduct a visual inspection and a swipe of duct interiors. Verify that an Accountability Form has been signed by the responsible party. LEED EQ 8.2: Visually verify walk-off mats, shoe storage area and/or central vacuum installation. LEED EQ 8.3: Verify that the Accountability Form has been signed by the responsible party.

Resources:
    Air Quality in the Home: American Lung Association
    US EPA: Indoor Air Quality Division
    Controlling Pollutants and Sources: US EPA
Synergies and Trade-Offs:

A project receiving points for LEED EQ 1 is not eligible to earn points for LEED EQ 8.1 or 8.3, but may earn points for LEED EQ 8.2. A project pursuing LEED EQ 8.2 must meet all the prerequisites in LEED EQ 2-10.

Radon Control: LEED EQ 9 Intent:

Reduce occupants' and construction workers' exposure to radon gas and other soil gas contaminants.

Prerequisites: Radon-Resistant Construction in High-Risk Areas: (Prerequisite) LEED 9.1

If the home is in EPA Radon Zone 1, design and build the home with radon-resistant construction techniques as prescribed by EQP, the International Residential Code, Washington State Ventilation and Indoor Air Quality Code, or some equivalent code or standard.

Credits: Radon-Resistant Construction in Moderate-Risk Areas (1 point). LEED DQ 9.2

If the home is outside EQP Radon Zone 1, design and build the home with radon-resistant construction techniques as prescribed by EPA, the International Residential Code, Washington State Ventilation and Indoor Air Quality Code, or other equivalent code or standard.

Note: Radon-resistant construction does not guarantee that occupants will not be exposed to radon. The Surgeon General and EQP recommend that every home in the country be tested for radon.

Overview:
    Since radon gas is reportedly the second major cause of lung cancer deaths in the US and the primary source of lung cancer after smoking, it is imperative that our homes be designed and tested for this deadly gas.
    Radon resistant construction is often a requirement by local building codes and zoning in the highest risk radon zones. It is recommended that even homes built in lower risk radon areas be equipment with radon resistant construction.
    In addition to radon exposure reduction in radon resistant construction, other ground-source pollutants will be reduced and it is generally considered good practice to limit exposure to all of these chemicals.
Approach:
    Consult EPA's radon map to determine whether the site is in Zone 1 (high risk). If so radon-protection measures are mandatory under this prerequisite. In all other zones, one point can be attained by implementing radon resistant construction.
    Incorporate radon resistant techniques early in the design process. Follow the techniques and strategies in EPA's Building Radon Out: A Step-by-Step Guide on How to Build Radon-Resistant Homes.

Radon resistant construction consists of five components:

    A gas-permeable layer
    sealing and caulking of all penetrations through the concrete slab
    vent pipe system to exhaust gasses from under the home
    A 4 to 6 inch layer of stone on grade under the slabs with a perforated drainage pipe vented to a passive vent stack.
    Heavy gauge plastic between concrete slab and soil
Calculations:

None

Exemplary Performance:

None

Verification and Submittals:

Builder/Project Team: Sign an Accountability Form to indicate that the home was built with radon-resistant construction.

Resources:
    ÷Radon-Resistant New Construction: US EPA
    EQP Map of Radon Zones
    American Association of Radon Scientists and Technologies
    Washington State Ventilation and Indoor Air Quality Code: Builder's Field Guide
Synergies and Trade-Offs:

A project receiving points for LEED EQ 1 is not eligible to earn points for LEED EQ 9.2.

Garage Pollution Protection: LEED EQ 10 Intent:

Reduce occupant exposure to indoor pollutants originating from an adjacent garage.

Prerequisites: No HVAC in Garage: (Prerequisite) LEED EQ 10.1

Place all air-handling equipment and ductwork outside the fir-rated envelope of the garage.

Credits: Minimize Pollutants from Garage: (2 points) LEED EQ 10.2

Tightly seal shared surfaces between garage and conditioned spaces, including all of the following:

In conditioned space above the garage:

    Seal all penetrations.
    Seal all connecting floor and ceiling joist bays; and
    Paint walls and ceilings (carbon monoxide can penetrate unfinished drywall through diffusion).

In conditioned spaces next to garage:

    Weather-strip all doors
    Place carbon monoxide detectors in adjacent rooms that share a door with the garage.
    Seal all penetrations; and
    Seal all cracks at the base of the walls

-And/OR-

Exhaust Fan in Garage: (1 point) LEED EQ 10.3

Install an exhaust fan in the garage that is rated for continuous operation and designed to be operated in one of the following ways.
Non-ducted exhaust fans must be 70 cfm or greater, and ducted exhaust fans must be 100 cfm or greater.

    Fan must run continuously; or
    Fan must be designed with an automatic timer control linked to an occupant sensor, light switch, garage door opening-closing mechanism, carbon monoxide sensor, or equivalent. The timer must be set to provide at least three air changes each time the fan is turned on.

-OR-

Detached Garage or No Garage: (3 points) LEED EQ 10.4 Overview:

Occupants health is at risk with a garage that is not completely sealed off from the living spaces of the home. Carbon monoxide can even penetrate unfinished drywall, so it is imperative that all drywall surface be thoroughly painted. There is also concern from off-gassing from power tools, chemicals, fertilizers and other inorganic compounds that are typically stored in the garage.

Approach:
    Best Practice is to build a detached garage or no garage at all.
    If the project includes a garage, install HVAC equipment in other spaces than the garage.
    Consider HVAC equipment with closed combustion which can typically be installed in closet areas or other storage type spaces.
    Proper and thorough air sealing between the house and garage is awarded and strongly encouraged. Use standard caulking, sealants and weather-stripping with special care given to the off-gassing of these materials.
    The Energy Rater will do a blower test on the areas surrounding the garage to detect any leakage.
    If an exhaust fan is installed in the garage, size the fan correctly and utilize a quiet operation fan.
    Continuous operation of the fan is not necessary and use of a timer if encouraged. Select an ENERGY STAR fan to save energy.
Calculations:

If installing an exhaust fan in the garage, use the following equation to calculate the length of time, in minutes that the garage fan must run to meet the credit criteria: Operating Time = Garage Size x 3 / Fan Capacity. where garage size is measure in cubic feet and fan capacity is measured in cfm.

Exemplary Performance:

None:

Verification and Submittals:

Trade: LEED EQ 10.3 Provide calculations to the builder or project team leader demonstrating that the garage exhaust fan provides the necessary air change. Deliver any garage exhaust fan equipment literature to the builder or project team leader.

Builder/Project Team: LEED EQ 10.3: Provide calculations to the Green Rater demonstrating that the garage exhaust fan provides the necessary air changes. Include garage exhaust fan equipment literature in the occupant's operations and maintenance manual.

Green Rater: LEED EQ 10.1: Visually verify that the requirements have been met. LEED EQ 10.2: Visually verify that the requirements have been met. LEED EQ 10.3: Visually verify the calculations for garage air changes. Visually verify that the appropriate garage exhaust equipment has been installed. LEED EQ 10.4: Visually verify that the home has no attached garage.

Resources:
    Air and Pollutant Transport from Attached Garages to Residential Living Spaces: National Institute of Standards and Technology Report.
Synergies and Trade-Offs:

A project receiving points for LEED EQ 10.1 is not eligible to earn points for LEED EQ 10.2, 10.3, or 10.4. A project receiving points LEED EQ 10.4 is not eligible to earn points for LEED EQ 10.2, or 10.3 and vice versa.

LEED EQ10.1 should be taken into consideration when designing the HVAC and heating and cooling distribution system (LEED EQ 5 ,6, LEED EQ 4, 6)

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