Heat Controller HTV Series - Page 17

Heat Controller, Inc. HTV/HTD/HTH SERIES
16
GROUND-LOOP HEAT PUMP APPLICATIONS
All alcohols should be premixed and
pumped from a reservoir outside of the
building when possible or introduced under
the water level to prevent fumes. Calculate
the total volume of uid in the piping system.
Then use the percentage by volume shown
in Table 2 and 2a for the amount of
antifreeze needed. Antifreeze
concentration should be checked from a
well mixed sample using a hydrometer to
measure specic gravity.
LOW WATER TEMPERATURE CUTOUT
SETTING
CXM Control
When antifreeze is selected, the FP1 jumper
(JW3) should be clipped to select the low
temperature (antifreeze 13°F) set point and
avoid nuisance faults (see “Low Water
Temperature Cutout Selection” in this
manual).
13
Minimum Temperature for Low Temperature Protection
Type
Table 2: Antifreeze Percentages by Volume
10°F 15°F 20°F 25°F
Methanol
100% USP Food Grade Propylene Glycol
Ethanol*
25%
38%
29%
21%
25%
25%
16%
22%
20%
10%
15%
14%
* Must not be denatured with any petroleum based product
Fluid Volume (gal. 100’ Pipe)
Pipe Size Volume (gal)
1” 4.1
1.25” 6.4
Copper
2.5” 9.2
Rubber Hose 1” 3.9
¾” IPS SDR11 2.8
1” IPS SDR11 4.5
1.25” IPS SDR11 8.0
1.5” IPS SDR11 10.9
2” IPS SDR11 18.0
1.25” IPS SCH40 8.3
1.5” IPS SCH40 10.9
Polyethylene
2” IPS SCH40 17.0
Unit Heat
Exchanger
Typical 1.0
Table 2a: Approximate Fluid Volume (gal.)
per 100’ of Pipe
Figure 6a: Typical Ground Loop
Application