Series ETSV - Models 40, 80
September 14, 2020
Page 14
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Refer to the National Fuel Gas Code, ANSI Z223�1 (NFPA 54) in the USA and CSA B149�1 Installation Codes in Canada,
as well as all local requirements for general venting guidance�
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Series ETSV Heaters may be installed vented or unvented�
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Series ETSV Heaters may be vented horizontally or vertically� This series of heaters are considered a Category I appliance
for vertical venting and a Category III appliance for horizontal venting�
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If heater is to be vented horizontally, the vent from building must:
* Be not less than seven feet above grade when located adjacent to public walkways�
* Terminate at least three feet above any forced air inlet located within ten feet�
* Terminate at least four feet below, four feet horizontally from or one foot above any door, window, or gravity inlet into
any building�
* Be located at least 12” (30cm) from any opening through which vent gases could enter a building�
* Extend beyond any combustible overhang�
* Be installed at a height sufficient to prevent blockage by snow�
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Secure all joints with three sheet metal screws�
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Optional outside air supply may be directed to the heater horizontally or vertically�
General Requirements
Venting
IMPORTANT
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Maximum total vent length allowed for any model heater is 15’ (3m)�
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Maximum total fresh air inlet duct length allowed for any model heater is 15’ (3m)�
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Total of vent length plus outside air supply duct length cannot exceed 30’ (6m) for any heater�
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If condensation in the vent pipe or outside air supply duct is a problem, shorten or adequately insulate the section�
Note:
The above stated requirements assume a maximum of 2 elbows in the total combination of vent and air supply
duct� Subtract 5’ of allowable length for each elbow if 3 or more elbows are used�
Un-vented Operation
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Requirements for combustion air supply and dilution air vary by jurisdiction, building type and specific installation details� See
local codes for guidance� In general, fresh air ventilation must be provided to the building space at 3 cfm per 1000 BTU/Hr
in Canada and 4 cfm per 1000 BTU/h in USA� The exhaust fan must be electrically interlocked with the heater�
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Optional outside air supply is not recommended for unvented heaters due to possible pressure imbalances in the building
space�
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Ensure that minimum combustible clearances are maintained for unvented heaters� Refer to Clearance to Combustibles, for
required clearance dimensions�
