EA New Homes Measures Guide - Earth Advantage

2012 Earth Advantage Residential
Measures Resource Guide
8.1.7
Whole-House On-Demand Hot Water Delivery System
Energy
Materials
Water
1 0 0 0 3
Description: A small pumping system delivers hot water to the faucet quickly. A manual switch must be installed to activate the pump. The
unit must be installed per manufacturer instructions. The point is not available if the unit triggers on a motion sensor.
This is not a typical hot water recirculation system in which a pump runs constantly to keep hot water immediately available to all fixtures.
(Some systems include timers to limit operation to the times of day when hot water is typically used, but this generally means the pump
still runs for many hours a day.) Water circulating in the pipes loses heat and drives up the stand-by loss of the water heater. Also, a small
amount of electricity is used to operate the pump.
Health
Land
Benefit: On-demand hot water delivery systems save water by delivering hot water to the fixture quickly. Without this system the occupant
will need to open the hot water tap and wait for the hot water to reach the fixture. This will allow the occupant to run the pump only when
hot water is needed. Homes with a centrally-located water heater may not benefit as much from the installation because of short plumbing
runs.
Verification: EA Rater will test the system to ensure proper operation. An on/off button will be located at the faucet furthest away from the
water heater.
8.1.8
Energy Health Land Materials Water
Short Hot Water Piping Runs: 20 feet one story - 10 feet for each additional 1 0 0 1 2
floor
Description: Plan plumbing runs to minimize the length of all hot water lines. Place water heater in a central location to reduce the length
of hot water lines to fixtures. To qualify for this measure pipe runs need to be limited to no more than 20 feet for single story homes plus
no more than 10 feet for each additional story. The key to efficient hot water distribution is to design the home's floor plan so that the
kitchen, laundry, and bathrooms are near a centrally-located water heater.
Benefit: It is typical to run the faucet while waiting for the water to warm up. In addition to being wasteful of water, such an approach also
wastes energy if the faucet is particularly far from the hot water source. Water sits in the pipes and cools, so that it must be flushed out
again the next time. All the hot water that went down the drain is also replaced by cold water in the water heater, and it takes energy to
heat it back up again.
This has the added advantage of requiring less plumbing labor and materials to install.
Verification: At rough inspection, EA Rater will measure the distance from each fixture to the water heater.
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