Rapid Engineering UHAT 150 Installation, Operation & Service Manual Download

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SECTION 7: V

ENTING

11 of 59

concentric vent box and a concentric vent/air intake
pipe penetrates the wall or roof. See Page 15,
Figure 9 and P age 16, Figure 10.
For separated combustion installation, the vent and
air intake must be fitted with an individual and
correctly sized sealed system and the vent and air
intake must terminate at approved wall and roof
terminals.
Separated combustion units may not be common
vented.

7.3 Horizontal Venting

Horizontally vented heaters must be individually
vented, no common venting.

Vent pipe must be sloped ¼" (.6 cm) for every 1' (.3

m).
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" (5 cm) air gap, may be used with a 4" (10 cm)
vent cap (P/N 90502102).

7.4 Vertical Venting

Vertically vented standard vented heaters can be

common vented (up to 4 heaters).

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

1' (.3 m).

For 4'' (10 cm) common vent, 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 14, Figure 7.

A vent shall not extend less than 2' (.6m) above the

highest point where it passes through a flat roof of a
building.

7.5 Maximum Vent Lengths Table

7.6 Vent Material

Vent material may be single wall 26 ga. (minimum)

galvanized steel or equal thickness stainless steel.

Completely seal all joints, refer to Page 10, Section
7.2.
If penetrating a combustible wall or roof, a listed
thimble with 2" (5 cm) clearance must be used.

Where local codes permit, a single section of type

B-1 vent material may be used at the roof or wall
penetration instead of a thimble. Ensure vent
manufacturer's clearance from vent material is
maintained. Seal annular space of the type B-1 vent
as well as all joints in the remaining vent.

7.7 Replacing an Existing Heater in a Venting
System

When replacing an existing heater in a venting

system, the venting system may not be properly
sized to vent the new heater. The following steps
must be followed with each piece of equipment
connected to the venting system placed in
operation, while any other equipment connected to
the venting system are not in operation.

1. Seal any unused openings in the venting

system.

2. Inspect the venting system for proper size and

horizontal pitch, as required by the NFPA 54/

ANSI Z223.1 - latest revision, National Fuel

Gas Code (US) or Standard CSA B149.1
Natural Gas and Propane Installation Code
(Canada) and these instructions. Determine
that there is no blockage or restriction, leakage,
corrosion and other deficiencies which could
cause an unsafe condition.

3. Close all building doors and windows and all

doors between the space in which the piece(s)
of equipment connected to the venting system
are located and other spaces of the building.

Turn on clothes dryers and any exhaust fans,

such as range hoods and bathroom exhausts
so that they shall operate at maximum speed.
Do not operate a summer exhaust fan. Close
fireplace dampers.

4. Follow the lighting instructions. Place the

equipment being inspected in operation. Adjust
thermostat so that the equipment will operate
continuously.

5. For any equipment having a draft hood, test for

draft hood equipment spillage at the draft hood
relief opening after five minutes of main burner
operation. Use the flame of a match or candle.

6. After it has been determined that each piece(s)

of equipment connected to the venting system
properly vents when tested as outlined above,
return doors, windows, exhaust fans, fireplace

Model UHA[T][M][X][S]150-400

# of Elbows