Installation & Maintenance Manual Owner's manual

ManualsBrandsKees ManualsHoodsIFG (INDIRECT FIRED GAS) MAKE-UP AIR UNITS - Duct Furnace

– 10 –

The appliance must be isolated from the gas supply

piping system by closing its individual manual shutoff

valve during any pressure testing of the gas supply

piping system at test pressure equal to or less than

1/2 psig (3.5 kPa).

For additional piping information, refer to National Fuel

Gas Code ANSI Z233.1-1999, or latest edition.

Figure 9a - Drip Leg Installation

Figure 9b - Field Piping Recommendations

DUCT SPECIFICATIONS

Ductwork connected to duct furnaces should have

removable access panels on both the upstream and

downstream sides of the unit. These openings should be

accessible when the unit is installed, and should be

sized so that smoke or reflected light can be observed

inside the casing to indicate the presence of leaks in the

heating equipment. The covers of the openings should

be attached in a manner that prevents leaks.

Ductwork which is outdoors must be insulated and

sealed to prevent water from entering either furnace or

building through the duct. Do not alter the flange

connection for the duct attachment; air may bypass

and cause combustion problems. Be sure to properly

seal to avoid any air leakage (refer to Figures 1 and 2).

GAS CONNECTIONS

All gas piping should be installed in accordance with

local codes. It is required that a ground union be

installed adjacent to the manifold for easy servicing. On

vertical runs, a drip leg should be provided upstream of

the control manifold (see figure 9a). An additional shut-

off must be located externally of the jacket enclosure

where required by local code. The location of this valve

must comply with the local codes. A 1/8-inch N.P.T.

plugged tapping, accessible for test gauge connection,

must be installed immediately upstream of the gas

supply connection to the unit. Field gas piping

recommendations are shown in Figure 9b.

It is recommended that the gas piping not be installed

through the bottom of the duct furnace bottom panel. If

piping must penetrate the duct furnace bottom panel, it

must be sealed to prevent water leakage.

To avoid equipment damage or

possible personal injury, do not connect gas

piping to this unit until a supply line pressure/leak

test has been completed. Connecting the unit

before completing the pressure/leak test may

damage the unit gas valve and result in a fire

hazard.

Do not rely on a shutoff valve to

isolate the unit while conducting gas pressure/leak

tests. These valves may not be completely shut off,

exposing the unit gas valve to excessive pressure

and damage. Do not overtighten the inlet gas piping.

This may cause stresses that would crack the valve.

Never use an open flame to detect

gas leaks. Explosive conditions may exist which

would result in personal injury or death.

The gas line should be supported so that no strain is

placed on the unit. Pipe compounds which are not

soluble to liquid petroleum gases should be used on

threaded joints.

The appliance and its individual shutoff valve must be

disconnected from the gas supply piping system during

any pressure testing of that system at test pressure in

excess of 1/2 psig (3.5 kPa).

3 In. (Min.)

76mm. (Min)

TO GAS CONTROLS

TO GAS LINE

ALTERNATE TO

GAS LINE

DRIP LEG

D3587

UNION

NIPPLE

ELBOW

NIPPLE

UNION

NIPPLE

D3726