268882-UIM-A-0407
18
Unitary Products Group
Vent and Supply (Outside) Air Safety Check Procedure
NOTE:
HUD approved Direct Vent (Sealed Combustion) and/or Direct
Vent (Sealed Combustion) furnaces are exempt from the Vent and Sup-
ply Air Safety Check Procedure. All other fuel-burning appliances
should be checked for proper operation.
Follow the procedure in ANSI Z223.1 National Fuel Gas Code. Refer to
the section on the “Recommended Procedure for Safety Inspection of
an Existing Appliance” or in Canada B149.1-00 Natural Gas and Pro-
pane Installation Code section on “Venting Systems and Air Supply for
Appliances” and all local codes. In addition to the procedure specified in
ANSI Z223.1, it is recommended that you follow the venting safety pro-
cedure below. This procedure is designed to detect an inadequate ven-
tilation system that can cause the appliances in the area to operate
improperly causing unsafe levels of Carbon Monoxide or an unsafe
condition to occur.
1.
Inspect the venting system for proper size and horizontal pitch.
Determine that there is no blockage, restriction, leakage, corrosion
or other deficiencies, which could cause an unsafe condition
2.
Close all building doors and windows and all doors.
3.
Turn on clothes dryers and TURN ON any exhaust fans, such as
range hoods and bathroom exhausts, so they shall operate at
maximum speed. Open the fireplace dampers. Do not operate a
summer exhaust fan.
4.
Follow the lighting instructions. Place the appliance being
inspected in operation. Adjust thermostat so the appliance shall
operate continuously.
5.
Test each appliance (such as a water heater) equipped with a draft
hood for spillage (down-draft or no draft) at the draft hood relief
opening after 5 minutes of main burner operation. Appliances that
do not have draft hoods need to be checked at the vent pipe as
close to the appliance as possible. Use a combustion analyzer to
check the CO2 and CO levels of each appliance. Use a draft
gauge to check for a downdraft or inadequate draft condition.
6.
After it has been determined that each appliance properly vents
when tested as outlined above, return doors, windows, exhaust
fans, fireplace dampers and any other gas burning appliance to
their normal condition.
7.
If improper venting is observed during any of the above tests, a
problem exists with either the venting system or the appliance
does not have enough combustion air (Supply Air from outside) to
complete combustion. This condition must be corrected before the
appliance can function safely.
NOTE:
An unsafe condition exists when the CO reading exceeds 40
ppm and the draft reading is not in excess of - 0.1 in. W.C. (-25 kPa)
with all of the appliance(s) operating at the same time.
8.
Any corrections to the venting system and / or to the supply (out-
side) air system must be in accordance with the National Fuel Gas
Code Z223.1 or CAN/CGA B149.1-00 Natural Gas and Propane
Installation Code (latest editions). If the vent system must be
resized, follow the appropriate tables in Appendix G of the above
codes or for this appliance and refer to Tables 4 & 5 of these
instructions.
Ventilated Combustion Air (Modular Home Installations
Only)
The ventilated attic space or a crawl space from which the combustion
air is taken must comply with the requirements specified in “COMBUS-
TION AIR SOURCE FROM OUTDOORS” in this instruction or in Sec-
tion 5.3, Air for Combustion and Ventilation of the National Fuel Gas
Code, ANSI Z223.1 (latest edition). This type installation requires two
properly sized pipes. One brings combustion air from a properly venti-
lated attic space or crawl space and a second pipe that extends from
the furnace vent connection (top right of unit) to the exterior of the build-
ing. Refer to Tables 4 & 5 for intake pipe sizing, allowable length and
elbow usage. Follow all notes, procedures and required materials in the
SEALED COMBUSTION AIR SUPPLY section in these instructions
when installing the combustion air pipe from the unit and into a venti-
lated attic space or crawl space. DO NOT terminate vent pipe in an Attic
or Crawl Space.
Ventilated Combustion Air Termination (Modular Home
Installations Only
Refer to Figure 24 for required attic termination for the combustion air
intake pipe. For attic termination, use two 90 elbows with the open end
in a downward position. Be sure to maintain 12” (30.5 cm) clearance
above any insulation, flooring or other material.
A crawl space combustion air installation consists of a straight pipe from
the PVC coupling on the burner box that extends into the crawl space
and terminates with a 1/4” (0.63 cm) mesh screen and no elbows.
Specially Engineered Installations
The above requirements shall be permitted to be waived where special
engineering, approved by the authority having jurisdiction, provides an
adequate supply of air for combustion, ventilation and dilution of flue
gases.
SECTION VII: CONDENSATE PIPING
CONDENSATE DRAIN
The condensate drain connection is provided in the furnace for field
installation. It consists of the hoses shown, a NPT male connection, and
a 1/2” (1.27 cm) female x 3/4” (1.9 cm) PVC slip coupling. Refer to Fig-
ure 25 for the condensate hose sizes and condensate drain connec-
tions.
IMPORTANT:
The condensate drain from the furnace may be con-
nected in common with the drain from an air conditioning coil if allowed
by local code.
IMPORTANT:
Condensate must be disposed of properly. Follow local
plumbing or wastewater codes. The drain line must maintain a 1/4" per
foot (0.635 cm per meter) slope to the drain.
CONDENSATE DRAIN TRAP AND DRAIN FREEZE
PROTECTION
Special precautions MUST be made if installing furnace in an area,
which may drop below freezing. This can cause improper operation or
damage to the equipment. If the furnace is installed in an area that has
the potential of freezing, the drain line and the drain trap must be pro-
tected. Use a 3 to 6 watt per foot at 115 vac, 40º F (4.4° C) self-regulat-
ing, shielded and waterproof heat tape. Wrap the drain trap and the
drain line with the heat tape and secure with ties. Follow the heat tape
manufacturer's recommendations.
FIGURE 24:
Attic Combustion Air Termination
Be sure to instruct the owner not to block this intake pipe.
FIGURE 25:
Condensate Drain Internal Hose Routing
12” MINIMUM BETWEEN
BOTTOM OF BELOW AND
ANY MATERIAL
12”
MIN.
CONDENSATE DRAIN TUBE 5/8” (1.59 cm)
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ON
