33
Table 8 — Maximum Allowable Pipe Length -- Ft./M) (Continued)
Variable Speed Vent Sizing Table
ALTITUDE
FT. (M)
UNIT SIZE
(BTUH)
Termination
Type
Direct & Non---
Direct Pipe
Dia. In. (mm)*
NUMBER OF 90
_
ELBOWS
1
2
3
4
5
6
6001 to 7000‡
(1829 to 2134)
60,000
2 Pipe or 2---In.
(51) Concentric
1---1/2 (38)
35 (11)
30 (9)
25 (8)
20 (6)
15 (5)
10 (3)
2 (51)
70 (21)
70 (21)
68 (21)
67 (20)
66 (20)
64 (20)
80,000
2 Pipe or 2---In.
(51) Concentric
1---1/2 (38)
20 (6)
15 (5)
10 (3)
5 (2)
NA
NA
2 (51)
70 (21)
70 (21)
68 (21)
67 (20)
62 (19)
57 (17)
100,000
2 Pipe or 2---In.
(51) Concentric
2 (51)
31 (9)
26 (8)
21 (6)
16 (5)
11 (3)
6 (2)
2---1/2 (64)
70 (21)
70 (21)
68 (21)
67 (20)
66 (20)
64 (20)
120,000
2 Pipe or 3---In.
(76) Concentric
3 (76)†
49 (15)
48 (15)
47 (14)
45 (14)
44 (13)
43 (13)
ALTITUDE
UNIT SIZE
(BTUH)
Termination
Type
Direct & Non---
Direct Pipe
Dia. In. (mm)*
NUMBER OF 90
_
ELBOWS
1
2
3
4
5
6
7001 to 8000‡
(2134 to 2438)
60,000
2 Pipe or 2---In.
(51) Concentric
1---1/2 (38)
32 (10)
27 (8)
22 (7)
17 (5)
12 (4)
7 (2)
2 (51)
66 (20)
65 (20)
63 (19)
62 (19)
60 (18)
59 (18)
80,000
2 Pipe or 2---In.
(51) Concentric
1---1/2 (38)
18 (6)
13 (4)
8 (2)
NA
NA
NA
2 (51)
66 (20)
65 (20)
63 (19)
62 (19)
57 (17)
52 (16)
100,000
2 Pipe or 2---In.
(51) Concentric
2 (51)
29 (9)
24 (7)
19 (6)
14 (4)
9 (3)
NA
2---1/2 (64)
66 (20)
65 (20)
63 (19)
62 (19)
60 (18)
59 (18)
120,000
2 Pipe or 3---In.
(76) Concentric
3 (76)†
46 (14)
44 (13)
43 (13)
41 (13)
40 (12)
38 (12)
ALTITUDE
UNIT SIZE
(BTUH)
Termination
Type
Direct & Non---
Direct Pipe
Dia. In. (mm)*
NUMBER OF 90
_
ELBOWS
1
2
3
4
5
6
8001 to 9000
Ft.‡
(2438 to 2743)
60,000
2 Pipe or 2---In.
(51) Concentric
1---1/2 (38)
30 (9)
25 (8)
20 (6)
15 (5)
10 (3)
5 (2)
2 (51)
62 (19)
60 (18)
58 (18)
56 (17)
55 (17)
53 (16)
80,000
2 Pipe or 2---In.
(51) Concentric
1---1/2 (38)
17 (5)
12 (3)
7 (2)
NA
NA
NA
2 (51)
62 (19)
60 (18)
58 (18)
56 (17)
51 (16)
46 (14)
100,000
2 Pipe or 2---In.
(51) Concentric
2 (51)
27 (8)
22 (7)
17 (5)
12 (4)
7 (2)
NA
2---1/2 (64)
62 (19)
60 (18)
58 (18)
56 (17)
55 (17)
53 (16)
120,000
2 Pipe or 3---In.
(76) Concentric
3 (76)†
43 (13)
41 (13)
39 (12)
37 (11)
35 (11)
34 (10)
ALTITUDE
UNIT SIZE
(BTUH)
Termination
Type
Direct & Non---
Direct Pipe
Dia. In. (mm)*
NUMBER OF 90
_
ELBOWS
1
2
3
4
5
6
9001 to 10000 ‡
(2743 to 3048)
60,000
2 Pipe or 2---In.
(51) Concentric
1---1/2 (38)
27 (8)
22 (7)
17 (5)
12 (4)
7 (2)
NA
2 (51)
57 (17)
55 (17)
53 (16)
51 (16)
49 (15)
47 (14)
80,000
2 Pipe or 2---In.
(51) Concentric
1---1/2 (38)
15 (5)
10 (3)
5 (2)
NA
NA
NA
2 (51)
57 (17)
55 (17)
53 (16)
51 (16)
46 (14)
41 (13)
100,000
2 Pipe or 2---In.
(51) Concentric
2 (51)
24 (7)
19 (6)
14 (4)
9 (3)
NA
NA
2---1/2 (64)
57 (17)
55 (17)
53 (16)
51 (16)
49 (15)
47 (14)
120,000
2 Pipe or 3---In.
(76) Concentric
3 (76)†
39 (12)
37 (11)
35 (11)
33 (10)
31 (10)
29 (9)
* Disk usage---Unless otherwise stated, use perforated disk assembly (factory---supplied in loose parts bag).
{
Wide radius elbow.
}
Vent sizing for Canadian installations over 4500 ft. (1372 M) above sea level are subject to acceptance by the local authorities having jurisdiction.
NA---Not Allowed; pressure switch will not make.
NOTES:
1. Do not use pipe size greater than those specified in table or incomplete combustion, flame disturbance, or flame sense lockout may occur.
2. Size both the combustion---air and vent pipe independently, determine the smallest diameter allowed by the table for each pipe, then use the larger diameter for both pipes.
3. Assume two 45
_
elbows equal one 90
_
elbow. Long radius elbows are desirable and may be required in some cases.
4. Elbows and pipe sections within the furnace casing and at the vent termination should not be included in vent length or elbow count.
5. The minimum pipe length is 5 ft. (1.5 M) for all applications.
CONDENSATE DRAIN
General
Condensate trap is shipped installed in the blower shelf.
Condensate trap can be RELOCATED to the side of the casing.
Condensate trap MUST be used for all applications.
An external trap is not required when connecting the field drain to
this condensate trap.
The field drain connection (condensate trap or drain tube coupling)
is sized for 1/2--in. CPVC, 1/2--in. PVC, or 5/8--in. ID tube
connection.
Drain pipe and fittings must conform to ANSI standards and
ASTM D1785, D2466, or D2846. CPVC or PVC cement must
conform to ASTM D2564 or F493. Primer must conform to
ASTM F656. In Canada, use CSA or ULC certified schedule 40
CPVC or PVC drain pipe, fittings, and cement.
When a condensate pump is required, select a pump which is
approved for condensing furnace applications. To avoid
condensate spillage, select a pump with an overflow switch.
Furnace condensate is mildly acidic, typically in the pH range of
3.2 to 4.5. Due to corrosive nature of this condensate, a condensate
pH neutralizing filter may be desired. Check with local authorities
to determine if a pH neutralizer is required.
Application
The furnace, A/C, and humidifier drains may be combined and
drained together. The A/C drain must have an external, field
supplied trap prior to the furnace drain connection. All drain
connections (furnace, A/C, or humidifier) must be terminated into
an open or vented drain as close to the respective equipment as
possible to prevent siphoning of the equipment’s drain.
See Fig. 37 for example of possible field drain attachment using
1/2--in. CPVC or PVC tee for vent and A/C or humidifier drain
connection.
355B
A
V
