Newmac LFR-75 - Exploded Assembly Diagrams

22
TABLE 6. DUCT SIZING FOR HEATING WITHOUT A/C COIL
Notes: 1. BTUH with maximum temperature rise.
2. Gas furnaces are rated in input capacity. Rated output capacity is 80 % of input.
3. Oil and electric furnaces are rated in output capacity.
TABLE 7. DUCT SIZING FOR HEATING & COOLING WITH A/C COIL IN DUCT
Air conditioning systems should never be sized on the basis of floor area alone. Knowledge of the approximate floor area (sq. ft.)
that can be cooled with a ton of air conditioning will be of invaluable assistance to you in avoiding serious mathematical errors.
Blower
Motor H.P.
Blower Wheel
Dia. X Width
5" RUNS
80 CFM
6" RUNS
115 CFM
7" RUNS
155 CFM
3 1/2x14"
170 CFM
1 1/2 ton
18,000
BTUH
600
CFM
1/4 H.P.
9" X 8"
10" X 8"
16" X 8"
or
12" round
8 5 4 4
16" X 8"
or
12" round
24 " X 8"
2 ton
24,000
BTUH
800
CFM
1/4 H.P.
9" X 9"
10" X 8"
22" X 8"
or
14" round
10 7 5 5
22" X 8"
or
14" round
22" X 12"
2 1/2 ton
30,000
BTUH
1000
CFM
1/3 H.P.
10" X 8"
10" X 10"
12" X 9"
20" X 10"
or
16" round
13 9 7 6
20" X 10"
or
18" round
30" X 12'
3 ton
36,000
BTUH
1200
CFM
1/3 H.P.
10" X 8"
10" X 10"
12" X 9"
24" X 10"
or
18" round
- 11 8 7
24" X 10"
or
18" round
30" X 12'
3 1/2 ton
42,000
BTUH
1400
CFM
1/2 H.P. 3/4
H.P.
10" X 8"
10" X 10"
12" X 9"
12" X 10"
24" X 12"
or
18" round
- 12 9 8
24" X 12"
or
18" round
30" X 14"
4 ton
48,000
BTUH
1600
CFM
1/2 H.P. 3/4
H.P.
12" X 7"
12" X 9"
12" X 10"
12" X 12"
32" X 10"
or
20" round
- 14 11 10
32" X 10"
or
20" round
30" X 18'
4 1/2 ton
54,000
BTUH
1800
CFM
3/4 H.P.
1 H.P.
12" X 8"
12" X 9"
12" X 10"
12" X 12"
32" X 10"
or
20" round
- 16 12 11
32" X 12"
or
22" round
30" X 20'
5 ton
2000
CFM
3/4 H.P.
1 H.P.
12" X 10"
12" X 12"
32" X 10"
or
20" round
- 18 13 12 32" X 14" 30" X 22'
Min. Number Supply Runs
@600 FPM
Min. Return Duct
Size at Furnace or Air
Handler
@800 FPM
Min. Return
Air Grille Size
(or equivalent)
@Face Velocity
of 500 FPM
Size of
O.D. Unit
Supply
Duct or
Extended Plenum
@ 800 FPM
Normal Air
Flow Req'd
@400 CFM
per Ton
Furnace
5" RUNS
80 CFM
6" RUNS
115 CFM
7" RUNS
155 CFM
3 1/2 X 14"
170 CFM
Return Duct
Furnace or
Air Handler
@800 FPM
Return Air Grille
(or equivalent)
@FaceVelocity
of 500 FPM
45,000
to
55,000
500
CFM
14" X 8"
or
12" round
100 7 5 4 3
14" X 8"
or
12" round
12" X 12"
60,000
to
70,000
700
CFM
18" X 8"
or
14" round
140 10 6 5 4
18" X 8"
or
14" round
24" X 10"
75,000
to
85,000
800
CFM
22" X 8"
or
14" round
170 10 7 5 5
22" X 8"
or
14" round
24" X 12"
95,000
to
105,000
900
CFM
24" X 8"
or
15" round
190 12 8 6 6
24" X 8"
or
15" round
24" X 12"
105,000
to
115,000
1100
CFM
22" X 10"
or
16" round
220 - 10 7 7
22" X 10"
or
16" round
30" X 12"
125,000
to
150,000
1400
CFM
24" X 12"
or
18" round
280 - 12 9 8
24" X 12"
or
18" round
30" X 14"
155,000
to
160,000
1600
CFM
1 - 35" X 10" or
20" round or
2 - 22" X 8"
360 - 14 10 10
32" X 10"
or
20" round
30" X 18"
165,000
to
170,000
1800
CFM
1 - 35" X 12"
or
2 - 22" X 10"
420 - 16 12 11 32" X 12" 30" X20"
175,000
to
190,000
2000
CFM
1 - 35" X 14"
or
2 - 22" X 12"
480 - 18 13 12 32" X 14" 30" X22"
Min. Number Supply Runs
@600FPM
MINIMUM SIZE
OUTPUT
CAPACITY
(See Notes)
Min. Air
Flow Req'd.
Supply Duct or
Extended Plenum
@800 FPM
Min. Sq. Inch
Needed for
Spec. CFM
(Total Area of
All Supply Duct)