Heat Recovery Systems
Install graywater
heat-recovery equipment in residential projects, commercial or
institutional buildings with multiple showers, and industrial
applications with large, continuous flows of hot water, such as
clothes washers. Manufactured products are available and well
proven.
Graywater
heat-recovery equipment can save up to 60% of water-heating energy
where hot water drain flow occurs at the same time as hot water
supply flow - such as multiple showers or industrial process water
systems. Systems serving fixtures on upper floors, where 60 in.
of vertical drain pipe is replaced by proprietary graywater heat-recovery
devices, need no pump and little or no maintenance. For below-grade
applications, systems with demand-operated pumps are available;
these need occasional service, and are best installed in a mechanical
room for regular maintenance access.
Where there
is less simultaneous hot water drain and supply flow (i.e., predominantly
baths, sinks, laundries, etc.), graywater heat-recovery systems
with heat storage add heat to the water supply to the hot water
tank. These require more space, and regular inspection and cleaning.
Cautions
- Systems
with pumps and storage require regular maintenance, and should
be located in mechanical rooms or other service areas.
