Thermo Pride CDX1-100N Installation And Operation Manual page 25

All installations and services must be performed by qualified service personnel.
: Outside combustion air must not come from an area that is directly adjacent to a
pool, hot tub or spa. Measures should be taken to prevent the entry of corrosive chemicals or
vapors to the combustion and ventilation air supply. Such chemicals include but are not limited to
chlorinated and/or fluorinated hydrocarbons such as found in refrigerants, aerosol propellants,
dry cleaning fluids, degreasers and removers. Other harmful compounds may come from
bleaches, air fresheners or mastics. Vapors from such products can form acid compounds when
burned in a gas flame. Should acid compounds form in your furnace; it may reduce the life of the
furnace.
H. CONNECTING THE FURNACE TO ROOF VENT/AIR TERMINATIONS
The furnace may be vented vertically through the roof if it is not possible to vent the furnaces through the
sidewall. The outlet/inlet of the vent and air intake terminations shall be a minimum of 12 inches above
highest anticipated snow level. The vent outlet must be installed a minimum of 12 in. above the air intake
inlet. The combustion air intake shall be installed upwind of the vent outlet when exposed to prevailing
winds. The exhaust vent and combustion air intake can be a minimum of 3 in. and a max. of 24 in. apart
(see Figure 13). NOTE: When the vent termination is installed correctly, no draft should be present in the
system during the furnace off cycle.
Figure 13
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