FAFCO 500 Series Installation Manual page 9

Solar-heated water is stored directly in an electric water heater with a single active upper element, rather than a
separate storage tank.
Electric water heater: An electric water heater can be either be one that is manufactured with only one element, or an electric water heater manufactured with two elements with the bottom element
disconnected. Single element electric water heaters replenish hot water slower than dual element water heaters. Refer to the local plumbing code for minimum water heater size requirements. Code
typically requires that water heaters be sized to meet a minimum "First Hour Rating" based on the number of bedrooms and bathrooms in a home. For single element water heaters that don't have
published First Hour Ratings, GAMA/AHRI recommends using 0.75 times the water volume which would require that an 80 gallon tank be used in homes as large as 2 bedroom, 2 bath and that a
120 gallon tank be used in larger homes. It is also recommended to install low flow shower heads which can significantly reduce hot water demand and save water. Raising the thermostat setting
on water heater element can also increase hot water capacity, but doing so may decrease realized energy savings.
Cold water shut-off valve
Hot water to home
Temperature
Control Valve
Self
Cleaning
Filter
P/T Valve
SINGLE TANK SYSTEM
Cold water supply
From solar collectors
To solar collectors
Fill valve
Check Valve
Drain valve
Temperature
Control Valve
Water heater
Overview (continued)
Expansion
reservoir
Air Vent/Pressure
Relief Valve
Solar collectors
Integrated
Circulation Module
(ICM)
8