Installation Manual

ManualsBrandsStyle Crest ManualsCooling & Air Quality2 ton 14 SEER 95% AFUE 45,000 BTU Revolv AccuCharge Mobile Home Air Conditioner and Gas Furnace System

MAXIMUM DIRECT VENT, DUAL PIPE LENGTH (FT.)

MG2R INPUTS

(BTU)

INLET / OUTLET

2” DIAMETER

INLET / OUTLET

3” DIAMETER

45,000 30 60

60,000 30 60

72,000 30 60

†

NOTES:

1. Subtract 2.5 ft. for each additional 2 inch long radius elbow, subtract

5ft for each additional 2” short radiious elbow, subtract 3.5 ft. for each

additional 3 inch long radius elbow, and 7 ft. for each additional 3

inch short radius elbow.

2. Two 45 degree elbows are equivalent to one 90 degree elbow.

3. This table applies for elevations from sea level to 2,000 ft. For higher

elevations, decrease pipe lengths by 8% per 1,000 ft of altitude.

Table 2. Vent Pipe Lengths

• The quality of outdoor air must also be considered. Be

sure that the combustion air intake is not located near

a source of solvent fumes or other chemicals which

can cause corrosion of the furnace combustion system.

(See page 5 for a sample list of substances).

• Route piping as direct as possible between the furnace

and the outdoors. Longer vent runs require larger

diameters. Vent piping must be sloped upwards 1/4”

per foot in the direction from the furnace to the terminal.

This ensures that any condensate ﬂows back to the

condensate disposal system.

• When a 2-pipe system is used, the combustion air

intake and the vent exhaust must be located in the

same atmospheric pressure zone. This means both

pipes must exit the building through the same portion

of exterior wall or roof as shown in Figure 1, Figure 2

& Figure 4 (page 9) and Figure 29 (page 37).

• Piping must be mechanically supported so that its weight

does not bear on the furnace. Pipe supports must be

installed a minimum of every ﬁve feet along the vent run to

ensure no displacement after installation. Supports may

be at shorter intervals if necessary to ensure that there

are no sagging sections that can trap condensate. It is

recommended to install couplings (Figure 29) along the

vent pipe, on either side of the exterior wall. Couplings

may be required by local code.

• If breakable connections are required in the combustion

air inlet pipe (if present) and exhaust vent piping, then

straight neoprene couplings for 3” piping with hose

clamps can be used. These couplings can be ordered

through your local furnace distributor. To install a

coupling:

1. Slide the rubber coupling over the end of the pipe

that is attached to the furnace and secure it with one

of the hose clamps.

2. Slide the other end of the rubber coupling onto the

other pipe from the vent.

3. Secure the coupling with the second hose clamp,

ensuring that the connection is tight and leak free.

Outdoor Terminations - Horizontal Venting

• Vent and combustion air intake terminations shall be

installed as shown in Figure 1, Figure 2, Figure 3, &

Figure 4 and in accordance with these instructions:

• Vent termination clearances must be consistent with the

NFGC, ANSI 2223.1/NFPA 54 and/or the CSA B149.1,

Natural Gas and Propane Installation Code. Table 13,

(page 36) lists the necessary distances from the vent

termination to windows and building air intakes.

• Vent and combustion air intake terminations must

be located to ensure proper furnace operation and

conformance to applicable codes. A vent terminal

must be located at least 3 feet above any forced air

inlet located within 10 feet. This does not apply to the

combustion air inlet of a direct vent (two pipe) appliance.

In Canada, CSA B149.1 takes precedence over these

instructions. See Table 13.

• All minimum clearances (Figure 2) must be maintained

to protect building materials from degradation by ﬂue

gases.

• For optimal performance, vent the furnace through a

wall that experiences the least exposure to winter winds.

Condensing furnace combustion products have very little

buoyancy, so Table 2 is to be used without consideration

of any vertical rise in the piping.

Vent Pipe Material

Vent and combustion air pipe and ﬁttings must be one

of the following materials in the list and must conform to

the indicated ANSI/ASTM standards.

MATERIALS STANDARDS

SCHEDULE 40PVC ................................................... D1785

PVC-DWV .................................................................. D2665

SDR-21 & SDR-26 ..................................................... D2241

ABS-DWV .................................................................. D2661

SCHEDULE 40 ABS ....................................................F628

FOAM / CELLULAR CORE PVC .................................F891

*POLYPRO

BY DURAVENT ................................. ULC-S636

When joining PVC to PVC, use cement that conforms to

ASTM standard D2564. PVC primer must meet standard

ASTM F656. When joining ABS to ABS, use cement that

conforms to ASTM standard D2235. When joining PVC to

ABS, use cement as speciﬁed in procedure from ASTM

standard D3138.

In Canada, all plastic vent pipes and ﬁttings including

any cement, cleaners, or primers must be certiﬁed as a

system to ULC S636. However this requirement does not

apply to the ﬁnish ﬂanges or piping internal to the furnace.

Vent Pipe Installation

CAUTION:

Combustion air must not be drawn from a

corrosive atmosphere.

This furnace has been certiﬁed for installation with zero

clearance between vent piping and combustible surfaces.

However, it is good practice to allow space for convenience

in installation and service.

• In the absence of local codes, the location of any

combustion air inlet relative to any vent terminal must

be at least 8 inches. This includes installations involving

more than one furnace.