Maritime Geothermal TF-45, Инструкция по установке и обслуживанию

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TABLE 8 - Heat Pump Size vs. Heated Area
for a Ground Loop System
Model ft
2
m
2
45 1400 130
55 2000 185
65 2600 240
75 3100 290
80 3500 325
TABLE 9 - Heat Pump Size vs. Heated Area
for an Open Loop System
Model ft
2
m
2
45 1800 165
55 2500 230
65 3200 295
75 3800 355
80 4200 390
Sizing and Ductwork
Heat Pump Sizing
TABLE 8 depicts a rough guideline as to the size of
home each heat pump size can handle for ground loop (closed
loop) installations.
TABLE 9 depicts a rough guideline as to the size of
home each heat pump size can handle for ground water (open
loop) installations.
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 ar-
ea.
IT IS HIGHLY RECOMMENDED THAT A PROPER HEAT
LOSS/GAIN ANALYSIS BE PERFORMED BY A PROFES-
SIONAL WITH APPROVED CSA F-280 SOFTWARE BEFORE
SELECTING THE SIZE OF UNIT REQUIRED FOR THE APPLI-
CATION. For heating dominant climates, we recommend
sizing the unit to 100% of the heating design load for maxi-
mum long term efficiency with minimal supplementary heat.
The unit should be installed as per CSA standard 448.2-02.
For ground loop applications, the ground loop should be
designed using suitable software with a multi-year analysis.
The analysis will result in a heat load for the coldest day,
which is influenced by, for example, the number of levels, the
size of the windows, the orientation of the home, attached gar-
age, bonus rooms, walk-in basement, and coldest outdoor tem-
perature for the region.
A heat pump model size can be selected by comparing the
calculated heat load to the standard capacity ratings, which are
listed in the Model Specific Information section of this manual.
For 100% heat pump sizing, choose a heat pump with a stand-
ard capacity rating that matches or just slightly exceeds the cal-
culated heat load.
Closed ground loops are normally designed to reach a
minimum temperature of just below freezing at the end of the
heating season, in order to take advantage of the latent heat of
groundwater (at least in northern climates). Hence, the Stand-
ard Capacity Ratings for Ground Loop Heating should apply in
all northern climates.
The Standard Capacity Ratings for Ground Water (open
loop) heat pumps assume a well water temperature of 50F
(10C). If the groundwater is not close to this temperature, it will
be necessary to consult the more detailed performance tables
later in the section for heat pump output at a different ELT.
In cooling dominant climates, the heat pump should be
similarly sized using the Ground Loop Cooling or Ground Water
Cooling Standard Capacity Ratings.
Note that the ‘triple function’ nature of the heat pump has
no effect on sizing procedure; it should still be sized for the total
load according to the above procedure.
Duct Systems - General
Ductwork layout for a heat pump will differ from traditional
hot air furnace design in the number of leads and size of main
trunks required. Air temperature leaving the heat pump is
normally 95º -105ºF (35-40ºC) , much cooler than that of a
conventional fossil fuel furnace. To compensate for this, larger
volumes of lower temperature air must be moved and
consequently duct sizing must be able to accommodate the
greater airflow without creating a high static pressure or high
velocity at the floor diffusers.
A duct system capable of supplying the required air flow is
of utmost importance. Maritime Geothermal Ltd. recommends
that the external static pressure from the duct system be kept
below 0.2 inches of water total. In some instances the number
of floor diffusers will actually double when compared to the
number that would be used for a hot air oil-fired furnace. Refer
to TABLE 12 at the end of this section.
1. Generally allow 100 cfm for each floor grill.
2. All leads to the grills should be 6'' in diameter (28sq.in. each).
3. The main hot air trunks should be at least 75% of the square
surface area of leads being fed at any given point.
4. Return air grills should have a minimum of the same total
square surface area as the total of the supply grills.
5. The square surface area of the return trunks should equal
the square surface area of the grills being handled at any
given point along the trunk.
It is
VERY IMPORTANT
that all turns in both the supply
trunks and the return trunks be made with
TURNING RADII
. Air
act like a fluid and, just like water, pressure drop is increased
when air is forced to change direction rapidly around a sharp or
irregular corner.
It is recommended that flexible collars be used to connect
the main trunks to the heat pump. This helps prevent any vibra-
tions from travelling down the ductwork. If a plenum heater is
installed, the collar should be at least 12” away from the heater
elements.
If desired, the first 5-10 feet of the main supply trunks can
be insulated internally with acoustical duct insulation to further
inhibit any noise from the unit from travelling down the ductwork.
If a plenum heater is installed, insulation should not be placed
within 12” of the heater elements.
DRAWING 002222PDG shows a typical installation.