Page 6 of 15
506325-01
Issue 1734
Figure 4. Securing Unit
Installation
Brackets
Remove and replace screw to secure bracket
(one each side)
Do not screw into the side of the drain pan, or into the
indoor coil or heat strip.
CAUTION
Air Filter
All indoor return air must be filtered. A washable filter is
furnished with the unit, located in the return air opening.
If return duct is installed, provisions must be made to
accommodate filter servicing. If a filter is installed at a
separate central return location, then the factory furnished
filter must be removed from the unit.
The filter should be cleaned at least three times during
each of the heating and cooling seasons, or more
frequently if unusual conditions are encountered. To clean
the washable filter, shake filter to remove excess dirt and/
or use a vacuum cleaner. Wash filter in soap or detergent
water and replace after filter is dry. It is not necessary to oil
the filter after washing.
If an installation is made in which it is more desirable to
mount the filter exterior to the unit, in the return duct work
or elsewhere, the washable filter can be used or replaced
with a disposable filter. If a disposable filter is used, use the
information provided in Table 3 when sizing the disposable
filter.
Table 3. Minimum Required Surface Area for
Disposable Filters
Model Number
Filter Area
MHP*12
192 square inches
MHP*18
288 square inches
MHP*24
384 square inches
MHP*30-36
480 square inches
* 9 and 10 EER Models
Condensate Drain
Provisions must be made to properly drain the indoor and
outdoor drain pans of this appliance.
Indoor drain connection: 1/2” NPT to 3/4” PVC fitting
(schedule 40). Outdoor drain connection: 3/4” NPT to 3/4”
PVC fitting (schedule 40 minimum). Both drains must be
trapped as shown in Figure 5. The drain line should pitch
gradually downward at least 1” per 10’ of horizontal run to
open drain.
If local codes require the use of metal condensate lines, do
not thread metal fittings into the unit drain pan. A 1/2” x 3/4”
threaded plastic nipple is available from the manufacturer
as a kit (see the
Accessories
section). Thread the 1/2”
end of the nipple into the unit drain pan and make the field
connection to the 3/4” end.
Use thread sealant on the threaded fittings. Install
threaded fittings by hand only.
Do not over torque the
fittings.
Do not thread metal condensate fittings to unit drain
pan.
CAUTION
Figure 5. Condensate Drain Installation
Fresh Air Intake (Fresh Air Models Only)
On fresh air capable models (designated by the FA in the
model number – e.g. 7MHP4-10-301FP), up to 5% fresh
air is drawn into the unit from outside when the indoor
blower comes on.
To access the fresh air intake feature, the threaded cap
must be removed from the fresh air intake pipe (see Figure
6). The fresh air intake pipe is located at the rear of the unit
return air intake. When not in use, cap should be placed
nearby in the air intake area in case it is needed in the
future.
