Sizing And Hydronic Information; Heat Pump Sizing; Hydronic Applications General; Table 4 - Heat Pump Size Vs. Heated Area For Ground Loop Systems - Boreal W-Series Installation And Service Manual

Sizing and Hydronic Information

HEAT PUMP SIZING

TABLE 4 depicts a rough guideline as to the size of home
each heat pump size can handle for ground loop installations.
TABLE 4 - Heat Pump Size vs. Heated Area
for a Ground Loop System
Model Size (tons)
25 2
45 3
55 4
65 5
75 6
TABLE 5 depicts a rough guideline as to the size of home
each heat pump size can handle for ground water installations.
TABLE 5 - Heat Pump Size vs. Heated Area
for a Ground Water System
Model Size (tons)
25 2
45 3
55 4
65 5
75 6
THE TABLES ABOVE ARE FOR INFORMATION ONLY,
THEY SHOULD NOT BE USED TO SELECT A UNIT SIZE.
They simply show on average what size unit is required for a
typical two-level home (main level and below grade basement)
with R-20 walls, R-40 ceiling and average size and number of
windows. The Heated Area is the area of the main level, The
tables account for a basement the same size as the heated
area.
BOREAL GEOTHERMAL INC. HIGHLY RECOMMENDS
THAT A PROPER HEAT LOSS/GAIN ANALYSIS BE PER-
FORMEDE BY A PROFESSIONAL INSTALLER WITH CSA
APPROVED SOFTWARE BEFORE SELECTING THE SIZE OF
UNIT REQUIRED FOR THE APPLICATION. For heating
dominant areas, we recommend sizing the unit to 100% of
the heating design load for maximum long term efficiency
with minimal supplementary heat. The unit should be in-
stalled as per CSA 448.2-02. For ground loop applications,
the ground exchanger should be designed using suitable
software with a multi-year analysis.
There are many factors to consider when sizing the heat
pump. Some of these factors include the number of levels, the
size of the windows, the orientation of the home, attached ga-
rage, bonus rooms, walk-in basement, coldest outdoor tempera-
ture, etc. The heat loss program will take all of these factors
into consideration in its calculations. An undersized installation
will require not be as efficient and will required expensive sup-
plemental heat to maintain a comfortable temperature in the
home, and the cost savings of having a geothermal heat pump
are greatly reduced.
Boreal Geothermal Inc.
Sq.ft. Sq.m.
800 75
1,400 130
2,000 185
2,600 240
3,100 290
Sq.ft. Sq.m.
1,000 95
1,800 165
2,500 230
3,200 295
3,800 355
Page 12
Once the total heat loss has been calculated, the unit can
be sized using the performance tables (from the specifications
document) in conjunction with the minimum expected entering
liquid temperature of the ground loop (well water temperature for
ground water system). The heat pump output must be able to
match the total heat loss at the selected entering water tempera-
ture in order to provide a comfortable environment with minimal
auxiliary heat.
HYDRONIC SYSTEMS - GENERAL
Hydronic systems typically provide heat through two different
types of media:

radiant in-floor heating

forced air heating via fan coil units
One of the benefits of hydronic systems is the flexibility in
setting up the heating system. Whereas a typical forced air sys-
tem has one central thermostat controlling the entire heating
system, the home may be sectioned into several areas called
zones with a hydronic system. Each zone has its own thermo-
stat, allowing simple separate temperature control of the individ-
ual areas in the home.
There are other uses for hydronic systems, the two most com-
mon being on-demand domestic hot water and pool/spa heat-
ing. Drawing 000530PDG
zones. A typical system consists of the heat pump, the buffer
tank and the zones. The heat pump's sole purpose is to main-
tain the buffer tank set point. Its operation is independent of the
zone operation.
Drawing 000533PDG shows a typical piping configuration for
a single unit with a buffer tank. This is a guideline for a simple
installation. There are many other configurations, such as sepa-
rate heating and cooling buffer tanks, multiple units connected
to one buffer tank, etc. It is recommended that the hydronic
system be designed by a qualified system designer to ensure
proper functionality.
Fan coils can be used to provide heating and/or cooling for
areas that do not have radiant in-floor heating. They provide a
means of air heating/cooling with minimal or no ductwork. Note
that the buffer tank temperature should be set for
if there are fan coils in the system.
Two port fan coils are recommended for connection to the
system if a single buffer tank is used for heating and cooling.
For systems with separate hot and cold buffer tanks, two port
fan coils are recommended for zones that provide only one func-
tion (heating or cooling), while four port fan coils are recom-
mended for zones that heat and cool. These are simply sugges-
tions, the fan coil selection will depend on the final system de-
sign.
It is recommended that all piping be insulated with 3/8" thick
closed cell pipe insulation. This is a MUST for any piping that is
used for cooling to prevent dripping onto floors and walls. Care
should be taking when wiring the system to ensure that radiant
in-floor heating zones are disabled whenever the heat pump is
switched to cooling mode.
shows the most common types of
115°F (46°C)
02 JULY 2009