Heat Controller 60 HZR-410A Heat Pump User Manual


 
Heat Controller, Inc. HBH SerieS Submittal Data
Heat Controller, Inc. HBH SERIES Engineering Design Guide
6
For operation in the shaded area when water is used in lieu of
an anti-freeze solution, the LWT (Leaving Water Temperature)
must be calculated. Flow must be maintained to a level
such that the LWT is maintained above 42°F [5.6°C] when
the JW3 jumper is not clipped (see example below). This is
due to the potential of the refrigerant temperature being as
low as 32°F [0°C] with 40°F [4.4°C] LWT, which may lead to a
nuisance cutout due to the activation of the Low Temperature
Protection. JW3 should never be clipped for standard range
equipment or systems without antifreeze.
Example:
At 50°F EWT (Entering Water Temperature) and 1.5 gpm/ton, a
8 ton unit has a HE of 72,200 Btuh.
To calculate LWT, rearrange the formula for HE as follows:
HE = TD x GPM x 500, where HE = Heat of Extraction (Btuh); TD
= temperature dierence (EWT - LWT) and GPM = U.S. Gallons
per Minute.
TD = HE / (GPM x 500)
TD = 72,200 / (12 x 500)
TD = 12°F
LWT = EWT - TD
LWT = 50 - 12 = 38°F - Antifreeze must be used
In this example, a higher ow rate will be required for EWTs at or below 50°F without antifreeze.
Performance Data
Selection Notes
WATER/BRINE
EWT
°F
FLOW
gpm
PD
psi
PD ft.
Heating - EAT 70°F
HC kW HE LAT COP
50
12.0 1.7 4.0
18.0 4.5 10.3
24.0 7.9 18.2
96.7 7.17 72.2 95.9 4.0
101.9 7.27 77.1 97.4 4.1
104.7 7.32 79.8 98.2 4.2
HBH096