Design And Installation Considerations; Draft; Negative Pressure - Heatilator BIR42-B Owner's Manual

B. Design and Installation Considerations
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.
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.
C. Draft
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
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.
Heatilator • Birmingham BIR42-B • 4059-681• 11/11
D. Negative Pressure
WARNING! Risk of Asphyxiation! Negative pressure can
cause spillage of combustion fumes and soot. Fire must
draft properly for safe operation.
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
NOTICE: The fireplace provides some outside air for
combustion. Other methods may be necessary if more air
is required.
NOTICE: Hearth & Home Technologies Inc. recommends the
use of direct vent appliances in basements.
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