CONNECTING HOT AIR DUCT
TO FURNACE
We strongly recommend that the hot air duct work be installed by a home heating specialist. If doing the instal- lation yourself, before you decide which installation will best suit your needs, consult a qualified heating technician and follow his recommendations as to the safest and most efficient method of installation.
The
Outside the house you must use 10 inch galvanized pipe, wrapped with weather proof, UV resistant insulation. The 12 inch return may be galvanized pipe and attached to the home so as to not pressurize the home.
NEVER reduce the 10” hot air or the 12” return air as this will result in restricted air flow and cause the furnace to not operate properly.
NEVER draw cold outside air into the blower housing. By doing so, the furnace’s heat chamber will not reach the necessary temperature to heat the home.
The duct work should be designed so the external static pressure does not exceed 0.2 inches water column while
developing air velocities of 600 to 1,000 feet per minute in the main trunk duct and 400 to 600 feet per minute at the registers. The heat outlet should never be less than ten inches (10”) round or 79 square inches.
This furnace must be installed with a cold air return system.
The system must be a minimum of twelve inches (12”) to readily transfer the cold air from the home back to the furnace. If desired, a cold air filter box may be constructed with a minimum opening of 225 square inches.
The
TYPES OF INSTALLATION
NO DUCT WORK INSTALLATION
Cold air return must be installed in all installations, even those without an air duct system. If you do not, the furnace will not be able to heat the home. A filter should be installed in the cold air return. Furnace filters should be checked and cleaned/replaced regularly.
When there is no duct system to connect the furnace to, keep the following in mind:
1.You must separate the hot air duct from the cold air return. Ideally, locate each at opposite ends of the home. This method will work well in homes that are built on concrete slabs and should create a good air flow. If you do not, air will not flow evenly through the home.
2.In homes with a basement, you may run the hot air duct to the basement and pull the cold air return from the main floor. This will create the perfect air flow since hot air rises.
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