Roberts Gorden 200, 350, 400, 300 Separated Combustion Heaters Models Uhas 150, Unvented Operation

COMBAT® UHA UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

6.2.2Separated Combustion Heaters (Models UHAS 150 - 400)

The heaters are designed to be installed as separated combustion heaters. The vent and air intake are run as separate pipes to the wall or roof terminals. See Page 12, Figure 8. As an option, the vent and air intake are run as separate pipes to a concentric vent box and a concentric vent/air intake pipe penetrates the wall or roof.

6.3 Unvented Operation

WARNING

Carbon Monoxide Hazard

Heaters installed unvented must be interlocked with sufficient building exhaust.

Heaters must be installed according to the installation manual.

Failure to follow these instructions can result in death or injury.

For unvented operation in commercial installations, sufficient ventilation must be provided in the amount of 4 cfm per 1000 Btu/h firing rate (United States); 3 cfm per 1000 Btu/h firing rate (Canada).

WARNING: Combustion by-products contain a chemical known to the State of California to cause cancer and birth defects or other reproductive harm.

6.4 Horizontal Venting

Horizontally vented heaters must be individually vented.

Vent pipe must be sloped ¼" (.6 cm) for every 1' (.3 m). For vent lengths greater than 5' (1.5 m), condensation will form. Insulation is recommended and condensation drains may be desired. For vents pitched up toward the vent terminal, place the condensation drain within 5' (1.5 m) of the heater.

In noncombustible walls only, vent terminal (P/N 02537801-1P) may be used.

For 4'' (10 cm) vents in either combustible or noncombustible walls, use vent terminal (P/N 90502100) or equivalent insulated vent terminal. Follow the manufacturer's instructions for proper installation.

Instead of an insulated vent terminal, a listed thimble (with 2" air gap) may be used with a 4" vent cap (P/N 90502102).

6.5 Vertical Venting

Vertically vented heaters can be common vented (up to 4 heaters).

For vent lengths greater than 5' (1.5 m), condensation will form. Insulation is recommended and condensation drains may be desired. Vent from the rear of the heater cabinet then run the vent vertically and use a condensate drain at the bottom of the vertical vent.

Vent pipe must be sloped 1/4'' (.6 cm) for every 1' (.3 m).

For 4'' (10 cm), an approved vent cap (P/N 90502102) must be used.

For 6'' (15 cm) common vent, an approved vent cap (P/N 90502103) must be used.

For common vertical venting of more than two heaters, See Page 10, Figure 5.

A vent shall not extend less than 2' (.6m) above the highest point where it passes through a flat roof of a building.

6.6 Length Requirements

If using vent lengths greater than 5' (1.5 m), condensation will form in the vent pipe. Insulation and additional sealing measures (high temperature silicone at all seams) are required.

The entire vent should be insulated with foil faced fiberglass insulation (1/2" thick, 1-1/2# density minimum).

Maximum Vent Lengths Table

Model UHA[S]	# of Elbows
150 - 400
40 ft (12.2 m)	1
35 ft (10.7 m)	2
30 ft (9.1 m)	3
25 ft (7.6 m)	4
20 ft (6.1 m)	5

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