EA New Homes Measures Guide - Earth Advantage

2012 Earth Advantage Residential
Measures Resource Guide
5.1.1
Premium Package - HRV/ERV system
Energy
Materials
Water
0 3 0 2 0
Description: HRVs and ERVs must be installed according to manufacturer's installation instructions, including air flow balancing. They
typically operate continuously on a low speed. Some have the ability to boost flow when more ventilation is needed. These may be used in
place of local ventilation in bathrooms, provided they deliver enough ventilation at high speed to meet local ventilation requirements.
Ideally, the duct system for HRVs and ERVs should be independent of a forced air heating system. However, they may be attached to a
forced air heating system if the air handler has an electrically-commutated motor (ECM), also called a brushless DC motor, blower set to
run at low speed during ventilation cycles. (Ventilation can occur during a heating or cooling cycle when the blower is operating at a higher
speed.)
Health
Land
Benefit: HRVs and ERVs are considered the premium ventilation systems. Using multiple points of exhaust and supply they provide
superior means of air circulation and distribution. By tempering incoming air, these units provide greater comfort in extreme climates than
other types of ventilation systems. They are highly effective and reduce the energy penalty associated with all fresh air ventilation. One
drawback to fresh air ventilation is that fresh air pulled into the building must be heated or cooled to the comfort temperature. While this
"energy penalty" is lower than the overall savings from air sealing, it is still a concern. Heat recovery ventilators (HRVs) address this issue by
capturing from 50 percent to 90 percent of the heat from outgoing air and transferring it to the incoming air. Energy Recovery Ventilators
(ERV's) take the idea one step further by recapturing the moisture from the outgoing air as well. This increases overall efficiency up to 85
percent and can prevent excessive dryness that sometimes occurs. Ventilators with ECM motors have the added value of super-efficient,
quiet operation. HRVs and ERVs are balanced ventilators in which the exhaust and supply air is roughly equal.
Verification: EA Rater will record the brand and model of the HRV or ERV along with the rated air flow. Rater will verify the Supply air is
routed from outdoor sidewalls, gable end wall, or soffit vent (with sealed ductwork to the exterior so no attic air can be drawn in.)
5.1.2
Supply Only - Forced air system
Energy
Materials
Water
0 2 0 1 0
Description: Outdoor air is introduced into the return side of the forced air HVAC system. An electronically controlled adjustable mechanical
damper must be used to control air flow to the air handler. The electronic control system must prioritize outdoor air delivery during normal
heating and cooling cycles. Supply air must be routed from outdoor sidewalls, gable end wall, or soffit vent. The fresh air duct must be
sealed with mastic paste. Avoid drawing supply air from the roof or any area that may generate harmful gasses or unpleasant odors.
Install a controller that is capable of meeting the requirements of ASHRAE 62.2. A 24-hour clock timer is not allowed. The HVAC contractor
must measure the flow of incoming fresh air to verify proper ventilation rate. The fresh air duct includes a manual or electronicallycontrolled
adjustable damper set to an airflow rate meeting ASHRAE 62.2 2006 requirements. The damper must be adjusted to limit
airflow to specified ventilation levels at the blower high speed setting.
Health
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Benefit: This system can improve the indoor air quality of the house by mixing fresh air from outside. Because fresh air is introduced
upstream of the typical air filter location, the incoming air can be filtered for pollen and dust that may be carried along with outdoor air.
Existing ductwork distributes the fresh air throughout the building.
Verification: EA Rater will engage the test mode to ensure that the furnace blower operates and the fresh air damper opens. The HVAC
contractor will complete the Accountability Form attesting that they have designed the system to comply with ASHRAE 62.2 and measured
the flow of the incoming fresh air to verify proper ventilation rate.
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