Sterling RF-90, RF-60, RF-75, RF-45, RF-30 specifications Horizontally Vented Unit Heaters Category

HORIZONTALLY VENTED UNIT HEATERS

(CATEGORY III)

All venting of residential tubular unit heaters must comply with the latest edition of CSA .10.96 (2nd ed.) requirement.

Category III horizontal venting arrangements are designed to use single wall vent pipe. These arrange- ments must terminate external to the building using either single wall or double wall (Type B) vent. See Figures 15, 16, and 18 for installa- tion requirements regarding these venting conditions. If double wall venting is used, components that are UL Listed and approved for Category III positive pressure venting systems must be used with one exception: a single 5 foot (1.52 M) section of 4 inch (102mm) Type B vent pipe with a draft hood connector may be used between the appliance vent connection and the vent terminal. Use Metalbestos Type B Gas Vent with a Metalbestos 4RV-DH Draft Hood Connector or Amerivent Type B Gas Vent with an Amerivent 4EDC Draft Hood Connector. See Figure 15A. If using a single section of Type B vent pipe, seal the annular space between the inner and outer sections of the draft hood connector with high temperature silicone sealant. See Figure 15B. Attach the draft hood connector to the appliance vent connection with screws and seal the joint with silicone sealant. Install a Type B vent thimble in the wall. Insert the vent pipe through the thimble and attach it to the adapter on the appliance. Seal the joint with silicone sealant or two wraps of aluminum foil tape. Install a vent cap on the outlet of the pipe and secure it with screws.

An Amerivent Americap, Fields Starcap, or Metalbestos vent cap must be supplied by the customer for each power vented unit. The vent pipe diameter MUST be 4 inches (102mm).

Vent Systems

Termination Clearance Requirements

	Minimum
Structure	Clearances for
	Termination
	Locations
	4 feet
	below
Door, window or	4 feet
any gravity air inlet	horizontally
	1 foot
	above
Forced air inlet within 10 ft.	3 feet
	above
Adjoining building or parapet	6 feet
Adjacent public walkways	7 feet
	above grade

The venting system for these appliances shall terminate at least 4 feet (1.2m) below, 4 feet (1.2m) horizontal from, or 1 foot (0.3m) above any door, window, or gravity vent air inlet into the building.

The vent terminal must be at least 12 inches (305mm) from the exterior of the wall that it passes through to prevent degradation of the building material by flue gases.

The vent terminal must be at least 1 foot (305mm) above grade, or in snow areas, at least 3 feet (1m) above the snow line to prevent blockage by snow.

Through the wall vent for these appliances shall NOT terminate over public walkways, or over an area where the condensate or vapor could create a nuisance or hazard or could be detrimental to the operation of regulators, relief valves, or other equipment.

The vent pipe equivalent length must not exceed 30 feet (9.14m) for the 30 and 45 unit sizes, and 40 feet (12.2m) for the 60, 75 and 90 unit sizes. Equivalent length is the total length of straight sections PLUS 5 feet (1.52m) for each 90 elbow and 2.5 feet (0.76m) for each 45 elbow.

Maintain 1 inch (25.4mm) between the vent pipe and combustible materials.

The vent terminal must be installed with a minimum horizontal clearance of 4 feet (1.2m) from electric meters, gas meters, regulators, and relief equipment.

Seal all vent pipe joints and seams to prevent leakage. Use General Electric RTV-108, Dow-Corning RTV-732, or equivalent silicone sealant with temperature rating of 500°F; or 3M #425 aluminum foil tape (or equivalent). The vent air system must be installed to prevent collection of condensate. Pitch horizontal pipes downward 1/4 inch per foot (21mm per meter) toward the outlet for condensate drainage.

Horizontal portions of the venting systems shall be supported at maximum intervals of 4 feet (1.2m) to prevent sagging (in Canada, support at 3 feet (1m) minimum intervals).

Insulate single wall vent pipe exposed to cold air or running through unheated areas. Insulate vent pipe runs longer than 10 feet (3m). Insulation should be a minmum of 1/2 inch thick foil faced fiberglass, 1-1/2# density insulation.

Each unit must have an individual vent pipe and vent terminal! Each unit MUST NOT be connected to other vent systems or to a chimney.

16