System information

ClimateMaster Geothermal Heat Pump Systems

Residential Products Technical Guide

High and

Low Voltage

Knockouts

Vibration Isolation Pad

To Thermostat

Figure 6: Typical Ground-Loop Application

Closed Loop Design/Installation Guidelines

Inside Piping - Polyethylene pipe provides an excellent no

leak piping material inside the building. Inside piping ﬁ ttings

and elbows should be limited to prevent excessive pressure

drop. Hose kits employing 1” rubber hose should be limited

in length to 10-15 feet [3 to 4.5 meters] per run to reduce

pressure drop problems. In general 2 feet of head [6 kPa]

pressure drop is allowed for all earth loop ﬁ ttings which

would include 10-12 elbows for inside piping to the Flow

Controller. This allows a generous amount of maneuvering

to the Flow Controller with the inside piping. Closed cell

insulation (3/8” to 1/2” [9.5 to 12.7 mm] wall thickness)

should be used on all inside piping where loop temperatures

below 50°F [10°C] are anticipated. All barbed connections

should be double clamped.

Flow Controller Selection - The pressure drop of the

entire ground loop should be calculated for the selection

of the Flow Controller (a pressure drop spreadsheet is

downloadable from the web site). In general, if basic loop

design rules are followed, units of 3 tons [10.6 kW] or less

will require only 1 circulating pump (UP26-99). Units from

3.5 to 6 tons [12.3 to 21.1 kW] will require a two pump

system (2 - UP26-99). Larger capacity units with propylene

glycol as antifreeze may require 2 - UP26-116 pumps.

However, the UP26-116 should be avoided where possible,

as power consumption of the 26-116 is signiﬁ cantly higher

than the 26-99, which will affect heating and cooling

operating costs. In many cases, where pressure drop

calcuations may call for 3 - UP26-99 pumps, try substituting

2 - UP26-116 pumps. This makes the installation much

easier and reduces cost. Chart 1 shows the various pump

combinations.

Loop pressure drop calculation should be performed for

accurate ﬂ ow estimation in any system including unit, hose

kit, inside piping, supply/return headers, circuit piping,

and ﬁ ttings. Use Tables 3A through 3F for pressure drop

calculations using antifreeze and PE/rubber hose piping

materials.