Shelter Furnace SF3048 User Manual Download Page 12

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The diagram below shows typical installations through a basement window, crawl space, or wall. Notice that the heat duct and return air

duct do not contain any 90° elbows. The use of 45° or less is advised for proper air delivery.
IF 10 INCH FLEX DUCT IS USED, IT MUST NOT BE EXPOSED TO THE OUTDOORS. IT IS FOR INDOOR USE ONLY.
WARNING: RISK OF FIRE! DO NOT USE ANYTHING OTHER THAN 250° F-RATED FLEX DUCT!

IMPORTANT: FOR TECHNICAL SUPPORT OR CUSTOMER SERVICE

ISSUES, DO NOT RETURN TO THE STORE (THE STORE DOES NOT HAVE

REPLACEMENT PARTS), CALL SHELTER FURNACE AT 1-800-875-4788.
TYPES OF INSTALLATIONS:

Your Shelter Furnace is designed to be a supplemental or central heating source for your home. This wood/coal burning furnace may

be installed in parallel with a properly operating electric, gas, or oil-fired central furnace that is listed or certified in accordance with a

nationally recognized safety standard within installation clearances as specified on the Shelter Furnace nameplate. When in a parallel

installation the static pressure of the central furnace plenum may not exceed .15 water column inches, and the maximum setting on

central furnace limit switch is 182° F. With the SF3048 wood and coal burning furnaces in an “Interconnection Arrangement” your Shelter

Furnace should be upstream from the central furnace. The Shelter Furnace warm air supply should never be connected to the return air

for the central furnace. A QUALIFIED INSTALLER SHOULD PERFORM INSTALLATION.

CENTRAL DUCT CONNECTIONS:

A qualified professional should do the installation. Maximum run should be 25 feet. A duct run in

excess of 25 feet will greatly restrict the air flow and heat output, therefore is not recommended. When connecting the Shelter Furnace

to a central duct system, avoid 90° elbows. As with any furnace, the more turns and branches in the ducting limit the airflow delivery. DO

NOT USE FLEX DUCT OUTSIDE.
Run 10 inch insulated galvanized hot air duct from the outside furnace through a window or wall of the house. Once inside, you may use

250º Fahrenheit rated insulated flexible hot air duct to connect the central duct system for the home. When using flexible duct inside the

home, it must be pulled tight with no offsets or elbows to prevent turbulence and slowdown airflow. Connect the duct with a 45° elbow

or at an angle so the hot air from the Shelter Furnace is delivered down stream. This will ensure proper airflow into the duct system.

Avoid delivering the hot air through the air conditioning coil, as this will cause an obstruction, reducing the amount of heat output. DO

NOT REDUCE THE SIZE OF THE HOT AIR DUCT. As with any furnace, longer runs and more turns and branches in the ducting greatly

reduce the airflow and heat output. Use of 90° elbows is strongly discouraged.

The 12 inch cold air return duct must run to the house to prevent pressurization of the home. Failure to connect the cold air return will

cause the furnace not to operate. NEVER REDUCE THE SIZE OF THE RETURN. Reducing the size of the cold air return will restrict

the hot air flow and put excess pressure on the blower motor. You may terminate the cold air return where you enter the house. This will

provide adequate circulation within the home. See diagram.

RETURN AIR DUCT

SUPPLY DUCT