Comfort-Aire HWW120 - Manual (Page 13)

12
Pre-Installation
Prior to installation, locate and mark all existing underground
utilities, piping, etc. Install loops for new construction before
sidewalks, patios, driveways, and other construction has
begun. During construction, accurately mark all ground loop
piping on the plot plan as an aid in avoiding potential future
damage to the installation.
Piping Installation
All earth loop piping materials should be limited to only
polyethylene fusion for inground sections of the loop.
Galvanized or steel fittings should not be used at any time
due to their tendency to corrode. All plastic to metal threaded
fittings should be avoided due to their potential to leak in
earth coupled applications and a flanged fitting substituted.
P/T plugs should be used so that flow can be measured
using the pressure drop of the unit heat exchanger in lieu of
other flow measurement means. Earth loop temperatures can
range between 25 to 110°F [-4 to 43°C], and 2.25 to 3 gpm of
flow per ton [2.9 l/m to 3.9 l/m per kW] of cooling capacity is
recommended in these applications. Upon completion of the
ground loop piping, pressure test the loop to assure a leak free
system. Horizontal Systems: Test individual loops as installed.
Test entire system when all loops are assembled. Vertical
U-Bends and Pond Loop Systems: Test Vertical U-bends and
pond loop assemblies prior to installation with a test pressure
of at least 100 psi [689 kPa].
Flushing the Earth Loop
Upon completion of system installation and testing, flush the
system to remove all foreign objects and purge to remove all
air. Flush the loop first with the unit isolated to avoid flushing
debris from the loop into the unit heat exchanger
Heat Controller, Inc. WATER-TO-WATER (HWW) SERIES Installation & Operation
Ground-Loop Heat Pump Applications
� CAUTION! �
The following instructions represent industry accepted
installation practices for Closed Loop Earth Coupled Heat
Pump Systems. They are provided to assist the contrac-
tor in installing trouble free ground loops. These instruc-
tions are recommendations only. State and Local Codes
MUST be followed and installation MUST conform to ALL
applicable Codes. It is the responsibility of the Installing
contractor to determine and comply with ALL applicable
Codes and Regulations.
Table 2: Antifreeze Percentages by Volume
Type
Min. Temp. for Low Temp. Protection
10°F
[-12.2°C]
15°F
[-9.4°C]
20°F
[-6.7°C]
25°F
[-3.9°C]
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
Antifreeze
In areas where minimum entering loop temperatures drop
below 40°F [5°C] or where piping will be routed through areas
subject to freezing, anti-freeze is needed. Alcohols and glycols
are commonly used as antifreezes, however your local sales
manager should be consulted for the antifreeze best suited
to your area. Freeze protection should be maintained to 15°F
[9°C] below the lowest expected entering loop temperature.
For example, if 30°F [-1°C] is the minimum expected entering
loop temperature, the leaving loop temperature would be
25 to 22°F [-4 to -6°C] and freeze protection should be at
15°F [-10°C] e.g. 30°F - 15°F = 15°F [-1°C - 9°C = -10°C]. All
alcohols should be premixed and pumped from a reservoir
outside of the building when possible or introduced under
water level to prevent fuming. Initially calculate the total
volume of fluid in the piping system using Table 1. Then use
the percentage by volume shown in Table 2 for the amount of
antifreeze. Antifreeze concentration should be checked from
a well mixed sample using a hydrometer to measure specific
gravity.
Low Water Temperature Cut-Out Setting CXM Control:
When an antifreeze is selected, the FP1 jumper [JW3] should be
clipped to select the low temperature (Antifreeze 15°F [-9.4°C])
setpoint to avoid nuisance faults. See Figure 5 [Page 14].
Table 1: Approximate Fluid Volume
(gallon) per 100' of Pipe
Fluid Volume (gal [liters] per 100’ [30 meters) Pipe)
Pipe Size Volume (gal) [liters]
Copper
1” 4.1 [15.3]
1.25” 6.4 [23.8]
2.5” 9.2 [34.3]
Rubber Hose 1” 3.9 [14.6]
Polyethylene
3/4” IPS SDR11 2.8 [10.4]
1” iPS SDR11 4.5 [16.7]
1.25” IPS SDR11 8.0 [29.8]
1.5” IPS SDR11 10.9 [40.7]
2” IPS SDR11 18.0 [67.0]
1.25” IPS SCH40 8.3 [30.9]
1.5” IPS SCH40 10.9 [40.7]
2” IPS SCH40 17.0 [63.4]
Unit Heat Exchanger Typical 1.0 [3.8]
Flush Cart Tank
10” Dia x 3ft tall
[254mm x 91.4cm tall]
10 [37.9]