7
Marvair Wall Mount Heat Pump I&O Manual
11/2021 New
1.4 Air Flow, Weights, Filter Sizes, Refrigerant Charges and Ambient Operating Ranges
Model Number
External Static Pressure (WET COIL)
0.10
0.20
0.25
0.30
0.40
0.50
MAA1042H/MAA2042H
1,533
1,457
1,427
1,348
1,293
1,223
MAA1048H/MAA2048H
1,763
1,672
1,634
1,590
1,511
1,445
MAA1060H/MAA2060H
2,201
2,130
2,083
2,064
1,972
1,900
Air flow ratings of 208-230v. Units are at 230v. Air flow ratings of 480 v. units are at 460 volts. Operation of units at a different voltage from the rating
point will affect air flow.
Table 1. Air Flow (Cubic Feet per Minute)
Model
Weight
Base
w/Economizer
w/3 Phase
w/Economizer & 3 Phase
MAA1042H/MAA2042H
MAA1048H/MAA2048H
MAA1060H/MAA2060H
Lbs
(Kg)
528
(239)
551 (250)
581 (264)
604 (274)
Table 2. Installed Weight (lbs (Kg)
Model
FILTER TYPE
INCHES
MILLIMETERS PART # FILTERS PER UNIT MERV RATING
MAA1042H/MAA2042H
MAA1048H/MAA2048H
MAA1060H/MAA2060H
Return Air Filter 18 x 20 x 2 457 x 508 x 25
91943
2
8
Table 3. Filter Size (inches)
Model
MAA1042H
MAA1048H
MAA1060H
A
C
D
A
C
D
A
C
D
Charge Amount
160
160
170
Model
MAA2042H
MAA2048H
MAA2060H
A
C
D
A
C
D
A
C
D
Charge Amount
185
185
190
Table 4. Refrigerant Charge (R410A, Ounces)
Basic Model
Special Option
TEMPERATURE RANGES
Non-Economizer
Base Unit
*20ºF - 131ºF (-7ºC - 55ºC)
Economizer-Equipped
Base Unit
-40ºF - 131ºF (-29ºC - 55ºC)
**An Optional FCC switch is required for the cooling Mode. Heating mode ratings are @47°F Outdoor
Temperature. Performance loss realized below this rating point.
Table 5. Ambient Temperature Operating Ranges
1.5 General Operation
Refrigerant Cycle
Marvair heat pumps use R-410A refrigerant in a conventional vapor-compression refrigeration cycle to
transfer heat. In the cooling mode, a double blower assembly blows indoor air across the evaporator (indoor
coil). Liquid refrigerant passing through the evaporator is boiled into gas by heat removed from the air.
The warmed refrigerant gas enters the compressor where its temperature and pressure are increased. The
hot refrigerant gas condenses to liquid as heat is transferred to outdoor air blown across the condenser
(outdoor coil) by the condenser fan. Liquid refrigerant is metered into the evaporator through a metering
device to repeat the cycle. In the heating mode, the process is reversed.
Heating Mode
During heating mode a special reversing valve reverses the flow of refrigerant through the system
exchanging the roles of the condenser and evaporator. Now the outdoor coil becomes the evaporator and
the indoor coil becomes the condenser. The refrigerant then flows through the outdoor coil, picks up heat
and becomes vaporized. The vapor then enters the compressor where it is compressed to a higher pressure
