Northern Heatpump NorthStar RD-WE-096 Installation & Operating Instructions Manual - page 21
08/19/2014
19
NI701
Figure 7 – Desuperheater Piping, Buffer Tank*
This arrangement is the most effective and
efficient and the recommended installation. The
buffer tank need not be as big as the standard
water heater; 40-gallon size can be very effective.
With this two tank system the desuperheater will
always act as a city/well water pre-heater and the
standard water heater (electric elements or gas)
only requires tempering energy which is a very
small percentage of domestic water heater energy
required.
Figure 7A – Desuperheater, Single Tank Concept*
Draw water from the bottom drain and returning it to the cold
water supply line. This method requires a check valve in the
cold water supply to prevent water from flowing into the
building or household cold water supply. A spring-type check
valve with a pressure rating of 1/2 PSI or less is recommended.
Inspect the dip tube in the water heater cold inlet for a check
valve. If a check valve is present it must be removed or damage
to the desuperheater circulator will occur.
Before restoring electrical supply to the water heater, adjust
the temperature setting on the tank.
On tanks with both upper and lower elements, the lower
element should be turned down to the lowest setting,
approximately 100° F (38° C). The upper element should
be adjusted to 120° F (49° C) to 130° F (54° C).
Depending upon the specific needs of the customer, you
may want to adjust the upper element differently.
On tanks with a single element, lower the thermostat
setting to 120° F (49° C).
CAUTION
Do not run desuperheater pump without supply from water heater. This will damage the pump.
*4-ton model shown, for water connection locations on other models reference product dimension pages.