EA New Homes Measures Guide - Earth Advantage

2012 Earth Advantage Residential
Measures Resource Guide
4.3.9
Non-ducted System
Energy
Materials
Water
0 3 0 3 0
Description: Designing the house with a non-ducted heating or cooling system. Systems that should receive these points are ductless heat
pumps, hydronic heat, and zonal electric.
Health
Land
Benefit: Duct systems account for a very large amount of the energy used in buildings. Much of the impact is direct heat loss and air
leakage from the ducts. However, large furnace blowers also create pressure differences throughout the building that contribute to building
air leakage. These imbalances can also pull moisture, allergens, and harmful soil gases into the house or create moisture problems in
building cavities. Forced air heating systems and the associated ductwork also consume a considerable amount of valuable space.
Verification: EA Rater will confirm a non-ducted heating system on the plans and during site visits.
4.3.10
Zonal Pressure Relief (ZPR) for ducted systems
Energy
Health Land Materials
Prerequisite
Description: A properly-installed HVAC duct system balances house pressures through all living spaces of the house. Air must have an
unobstructed path from each supply register to the return grille. Zonal pressure relief is required in any room that is 75 square feet or
larger, has a supply register, and has a door. Pressure relief can be provided in several ways. 1) Cut the bottom of the door to allow a full
one-inch space between the bottom of the door and the top of the finished flooring. 2) Install a transfer grille through the wall. 3) Install a
transfer duct from the room into the central zone. 3) Install a direct return in each room. The goal of pressure relief is to maintain a
pressure difference across the door of no more than 3 Pa. Door undercuts are effective only in smaller rooms with only one supply. In
rooms with more than one supply, a transfer duct or direct return is usually the most effective method.
Water
Benefit: Forced-air heating systems include large blowers to move conditioned air through the house. Ideally, all the air that is delivered to
the house through supply registers flows through the house to the central return. Unfortunately, interior doors block the ideal air flow and
create severe pressure imbalances. Supply air is ?bottled up? behind bedroom doors, while other areas are starved for air. Pressure
problems in houses can also cause naturally-vented combustion appliances to back-draft, which brings harmful flue gasses into the
building. Systems with adequate pressure relief provide better safety, comfort, and efficiency.
Verification: For ducted systems, EA Rater will identify the method of zonal pressure relief for each room (usually bedrooms) and will
measure zonal pressure. The pressure difference of each bedroom with respect to the main living area (or hallway) must not exceed +5 Pa.
4.3.11
Pre-fabricated Sealed Boot
Energy
Materials
Water
0 1 0 0 0
Description: A pre-fabricated sealed boot is a mounting system that allows air supply boots to be tightly sealed to a ceiling, wall, or sub
floor. (A boot is the termination that connects a round duct to a rectangular grille opening.) Some models come with an adjustable boot
hanger that quickly attaches between joists, trusses, or studs. A foam gasket provides a tight seal to the drywall or sub floor. A cardboard
cover prevents dirt and debris from entering the duct during construction. It is most common to use this product in the ceiling.
Health
Land
Benefit: This product can save labor, keep ducts clean, and reduce air leakage.
Verification: EA Rater will visually verify the presence of pre-fabricated sealed boots.
4.4 Air Quality
Page 37 of 70