16 7060-227J August 13, 2018Explorer I I I W ood StoveNegative pressure results from the imbalance of air availablefor the appliance to operate properly. It can be strongest inlower levels of the house.Causes include:• Exhaust fans (kitchen, bath, etc.)• Range hoods• Combustion air requirements for furnaces, waterappliances and other combustion appliances• Clothes dryers• Location of return-air vents to furnace or airconditioning• Imbalances of the HVAC air handling system• Upper level air leaks such as:- Recessed lighting- Attic hatch- Duct leaksTo minimize the effects of negative air pressure:• Install the outside air kit with the intake facing prevailingwinds during the heating season• Ensure adequate outdoor air for all combustionappliances and exhaust equipment• Ensure furnace and air conditioning return vents arenot located in the immediate vicinity of the appliance• Avoid installing the appliance near doors, walkways orsmall isolated spaces• Recessed lighting should be a “sealed can” design• Attic hatches weather stripped or sealed• Attic mounted duct work and air handler joints andseams taped or sealedM. Negative PressureL. Clear Space• Do NOT place combustible objects within 4 ft (1.2 m) ofthe front of appliance (Figure 16.1).• Mantel - avoid placing candles and other heat-sensitiveobjects on mantel or hearth. Heat may damage theseobjects.Figure 16.1Maintain 4 ft (1.22m) clearance tocombustible in front of applianceWARNINGAsphyxiation Risk.• Negative pressure can cause spillage ofcombustion fumes, soot and carbon monoxide.• Appliance needs to draft properly for safety.WARNINGDo NOT place combustible objects in front of theappliance. High temperatures may ignite clothing, furnitureor draperies.