22
VII Select net heating capacity of unit to meet
design condition requirements.
Enter the 62AQ060 Heating Rating table found in
the Energy$Recycler Product Data. At 450 cfm, 70 F
and 0° F find the heating value for the Energy$Recy-
cler to be 15.2 Btuh. Since the Energy$Recycler uses
room air, the instantaneous heat is also the Integrated
Heat Rating.
The customer heat requirement is 85,000 Btuh.
Fan heat from Step II
4,851 Btuh
Energy$Recycler Heat Capacity
15,200 Btuh
add Energy$Recycler optional
supply fan heat if supplied
+
0 Btuh
Total Unit heat with Energy$Recycler
20,051 Btuh
Determine additional electric heat capacity in kW.
The required heating capacity is 85,000 Btuh. There-
fore, 64,949 Btuh (85,000-20,051) additional heat is
required.
The output capacity for the 48HJE006 is 92,000
Btuh, which is sufficient.
Total unit net heating capacity is 112,571 Btuh
(92,000 + 20,571).
VIII Determine net cooling capacity.
Cooling capacities are gross capacities and
do not include indoor (evaporator) or optional
Energy$Recycler supply fan heat.
Determine net cooling capacity using the following
formula:
Net Capacity = (Gross Capacity Rooftop Unit
+ Gross Capacity Energy$Recycler) – (IFM Heat
+ Optional Energy$Recycler Supply Fan motor heat)
Gross Total Cooling
Rooftop unit
59,420 Btuh
Energy$Recycler
13,000 Btuh
Total
72,420 Btuh
Less
IFM heat (from Step II)
–4,851 Btuh
Optional Energy$Recycler Supply
Fan Motor Heat
none
Net Total Capacity
67,569 Btuh
Gross Sensible Cooling
Rooftop unit
43,420 Btuh
Energy$Recycler
10,090 Btuh
Total
53,510 Btuh
Less
IFM heat (from Step II)
–4,851 Btuh
Optional Energy$Recycler Supply
Fan Motor Heat
none
Net Sensible Capacity
48,659 Btuh
IX
Determine the operating watts of the unit.
a) Cooling with Energy$Recycler in operation:
Rooftop unit:
Compressor watts from cooling
capacity tables . . . . . . . . . . . . . . . . 4,440 watts
Indoor fan motor from Step II** . . . . 1,421 watts
Outdoor fan motor from Physical Data table
find
1
/
4
hp**.
Assume OD motor efficiency is 0.75.
Watts = (746 x hp)/(motor Eff)
= (746 x
1
/
4
)/(0.75)
= 249 watts
**Dual circuit units will have two indoor and two
outdoor fans, double values.
b) Energy$Recycler:
Compressor watts from
Energy$Recycler Product Data
1,060 watts
Optional supply fan from
Energy$Recycler Product Data
fan curves
none
Exhaust fan, from Energy$Recycler
Product Data fan curve
at 450 cfm, 0.2 in. wg Static
110 watts
Total watts for the unit in operation
at design conditions
7,200 watts
X
Electrical data RLA, FLA, LRA, MCA and
MOCP.
Separate Power Supply:
If the 62AQ is wired for separate power see the Elec-
trical Data table.
Single Power Supply with Unit:
The unit is 230-1-60 Hz. Look up the 48JH006
without convenience outlet in the Electrical Data
Table. Find unit electrical data. For the rooftop unit
the data is MCA = 46.3 amps, MOCP = 60 amps,
Min Unit Disconnect Size FLA = 45, and LRA = 216.
From the Table of “X” and “Y” values in the Ener-
gy$Recycler Product Data literature, find 230 v, for
62AQ060300, “X” = 8.1 amps and “Y” = 9.3 amps.
Add “X” amps to the MCA and MOCP and add “Y”
amps to the minimum disconnect size.
**The calculated MOCP is 68.1 amps; it is rounded
down to 60 amps. Compare it to MCA; it must be
larger than the MCA of 54.4 amps, so it is acceptable
as is.
MCA
MOCP
FLA
LRA
SRT
46.3
60
45
216
62AQ
8.1
8.1
9.3
31.7
Total
54.4 amps 68.1** amps 54.3 amps 247.7 amps
Selection procedure (with 48HJ006 example) (cont)
