Proper Vent/Flue And Combustion Air Piping Practices - Maytag Amana MEC96 Series Installation Instructions Manual

PVC primer meeting ASTM F656 and PVC solvent cement
meeting ASTM D2564 specifications must be used. Fittings
must be DWV type fittings meeting ASTM D2665 and ASTM
D3311. Carefully follow the manufactures instructions for
cutting, cleaning and solvent cementing of PVC.
For Canadian Installations; field supplied PVC venting ma-
terials must be UL S636 listed. NOTE: Requirement does
not apply to the combustion air pipe.
As an alternative to PVC pipe, primer, solvent cement, and fit-
tings, ABS materials which are in compliance with the following
specifications may be used. Two-or-three-inch ABS Schedule
40 pipe must meet ASTM D1527 and, if used in Canada, must
be CSA listed. Solvent cement for ABS to ABS joints must meet
ASTM D2235 and, if used in Canada, must be CSA listed. The
solvent cement for the PVC to ABS transition joint must meet
ASTM D3138. Fittings must be DWV type fittings meeting ASTM
D2661 and ASTM D3311 and, if used in Canada, must be CSA
listed. Carefully follow the manufacturers' instructions for
cutting, cleaning, and solvent cementing PVC and/or ABS.
All 90° elbows must be medium radius (1/4 bend DWV) or long
radius (Long sweep 1/4 bend DWV) types conforming to ASTM
D3311. A medium radius (1/4 bend DWV) elbow measures 3
1/16" minimum from the plane of one opening to the center
line of the other opening for 2" diameter pipe, and 4 9/16"
minimum for 3" pipe.
Proper Vent/Flue and Combustion Air Piping Prac-
tices
Adhere to these instructions to ensure safe and proper furnace
performance. The length, diameter, and number of elbows of
the vent/flue pipe and combustion air pipe (when applicable)
affects the performance of the furnace and must be carefully
sized. All piping must be installed in accordance with local
codes and these instructions.
Some models require the use of 3" pipe. Do not transition
from a 2" to 3" pipe in a horizontal section of pipe as this
may create a water trap.
PREFERRED
Figure 4
ACCEPTABLE
Piping must be adequately secured and supported to prohibit
sagging, joint separation, and/or detachment from the fur-
nace. Horizontal runs of vent/flue piping must be supported
every three to five feet and must maintain a 1/4 inch per foot
downward slope, back towards the furnace, to properly return
condensate to the furnace's drain system. Allowances should be
made for minor expansion and contraction due to temperature
variations. For this reason, particular care must be taken to
secure piping when a long run is followed by a short offset of
less than 40 inches.
Precautions should be taken to prevent condensate from freez-
ing inside the vent/flue pipe and/or at the vent/flue pipe termi-
nation. All vent/flue piping exposed to freezing temperatures
below 35°F for extended periods of time must be insulated with
1/2" thick closed cell foam. Also all vent/flue piping exposed
outdoors in excess of the terminations shown in this manual (or
in unheated areas) must be insulated with 1/2" thick closed
cell foam. Inspect piping for leaks prior to installing insulation.
13
TRANSITION NO LESS
THAN 45 DEGREES TO
HORIZONTAL PLANE TO
AVOID CREATING A WATER
TRAP IN VENT PIPING.
Figure 5
NO TRANSITION ON
HORIZONTAL PLANE,
THIS CREATES A
WATER TRAP AND
RESTRICTS FLUE
GASES
Figure 6