Hearth and Home Technologies BIR42-B - Manual (Page 15)

15
B. Design and Installation Considerations
Draft is the pressure difference needed to vent fireplaces
successfully. When a fireplace is drafting successfully, all
combustion by-products are exiting the home through the
chimney.
Considerations for successful draft include:
• Preventing negative pressure
• Location of fireplace and chimney
Before installing, determine the following:
• Where the fireplace is to be installed.
• The vent system configuration to be used.
• Gas supply piping.
• Framing and finishing details.
• Whether optional accessories are desired.
NOTICE: Check building codes prior to installation.
• Installation MUST comply with local, regional, state and
national codes and regulations.
• Consult insurance carrier, local building inspector, fire
officials or authorities having jurisdiction over restrictions,
installation inspection and permits.
Negative pressure results from the imbalance of air avail-
able for the fireplace to operate properly. It can be stron-
gest in lower levels of the house.
Causes include:
• Exhaust fans (kitchen, bath, etc.)
• Range hoods
• Combustion air requirements for furnaces, water heaters
and other combustion appliances
• Clothes dryers
• Location of return-air vents to furnace or air conditioning
• Imbalances of the HVAC air handling system
• Upper level air leaks such as:
- Recessed lighting
- Attic hatch
- Duct leaks
To minimize the effects of negative air pressure:
• Ensure adequate outdoor air for all combustion appliances
and exhaust equipment
• Ensure furnace and air conditioning return vents are not
located in the immediate vicinity of the fireplace
• Avoid installing the fireplace near doors, walkways or small
isolated spaces
• Recessed lighting should be a “sealed can” design
• Attic hatches weather stripped or sealed
• Attic mounted duct work and air handler joints and seams
taped or sealed
• Basement installations should be avoided
WARNING! Risk of Asphyxiation! Negative pressure can
cause spillage of combustion fumes and soot. Fire must
draft properly for safe operation.
NOTICE: Hearth & Home Technologies assumes no
responsibility for the improper performance of the fireplace
system caused by:
• Inadequate draft due to environmental conditions
• Downdrafts
• Tight sealing construction of the structure
• Mechanical exhausting devices
• Improper positioning of the chimney in a not-recommended
location on the roof.
NOTICE: Hearth & Home Technologies Inc. recommends the
use of direct vent appliances in basements.
D. Negative Pressure
C. Draft
NOTICE: The fireplace provides some outside air for
combustion. Other methods may be necessary if more air
is required.
Heatilator • Birmingham BIR42-B • 4059-681C• 9/12