Air from Outside

If air from outside is brought in for combustion and ventilation, the confined space shall be provided with two permanent openings. One opening shall be within 12” (305 mm) of the top of the enclosure and one within 12” (305 mm) of the bottom. These openings must communicate directly or by ducts with the outdoors or spaces (crawl or attic) that freely communicate with the outdoors or indirectly through vertical ducts. Each opening shall have a minimum free area of 1 square inch per 4,000 Btu (645 mm² per .59 kW) per total input rating of all equipment in the enclosure (See Figure 5).

EQUIPMENT IN CONFINED SPACE − ALL AIR FROM OUTSIDE (Inlet Air from Crawl Space and Outlet Air to Ventilated Attic)

VENTILATION LOUVERS (Each end of attic)

ROOF TERMINATED

EXHAUST PIPE

 

 

OUTLET

 

 

AIR

SIDE WALL

FURNACE

 

TERMINATED

 

VENTILATION

EXHAUST PIPE

 

 

LOUVERS

(ALTERNATE

INLET

(For unheated

LOCATION)

AIR

crawl space)

NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch per 4,000 Btu (645 mm2 per 1.17 kW) per hour of the total input rating of all equipment in the enclosure.

FIGURE 5

If air from outside is brought in for combustion and ventilation, the confined space must have two permanent openings. One opening shall be within 12 inches (305 mm) of the top of the enclosure and one opening within 12 inches (305 mm) of the bottom. These openings must communicate directly or by ducts with the outdoors or spaces (crawl or attic) that freely communicate with the outdoors or indirectly through vertical ducts. Each opening shall have a minimum free area of 1 square inch (645 mm²) per 4,000 Btu (1.17 kW) per hour of total input rating of all equipment in the enclosure. See figures 5 and 6. When communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of 1 square inch (645 mm²) per 2,000 Btu (.56 kW) per total input rating of all equipment in the enclosure. See Figure 7.

When ducts are used, they shall be of the same cross- sectional area as the free area of the openings to which they connect. The minimum dimension of rectangular air ducts shall be no less than 3 inches (75 mm). In calculating free area, the blocking effect of louvers, grilles, or screens must be considered. If the design and free area of protective covering is not known for calculating the size opening required, it may be assumed that wood louvers will have 20

to 25 percent free area and metal louvers and grilles will have 60 to 75 percent free area. Louvers and grilles must be fixed in the open position or interlocked with the equipment so that they are opened automatically during equipment operation.

EQUIPMENT IN CONFINED SPACE − ALL AIR FROM OUTSIDE (All Air Through Ventilated Attic)

ROOF TERMINATED

VENTILATION LOUVERS

EXHAUST PIPE

(Each end of attic)

 

OUTLET

 

AIR

SIDE WALL

FURNACE

INLET AIR

(Ends 12" above

TERMINATED

bottom)

EXHAUST PIPE

 

 

(ALTERNATE

 

 

LOCATION)

 

 

NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch per 4,000 Btu (645 mm2 per 1.17 kW) per hour of the total input rating of all equipment in the enclosure.

FIGURE 6

EQUIPMENT IN CONFINED SPACE −

ALL AIR FROM OUTSIDE

ROOF TERMINATED

EXHAUST PIPE

 

OUTLET AIR

SIDE WALL

FURNACE

TERMINATED

 

EXHAUST PIPE

INLET AIR

(ALTERNATE

LOCATION)

 

NOTE−Each air duct opening shall have a free area of at least one square inch per 2,000 Btu (645 mm2 per .59 kW) per hour of the total input rating of all equipment in the enclosure. If the equipment room is located against an outside wall and the air openings communi- cate directly with the outdoors, each opening shall have a free area of at least 1 square inch per 4,000 Btu (645 mm2 per 1.17 kW) per hour of the total input rating of all other equipment in the enclosure.

FIGURE 7

Page 8 of 48

Issue 1109

506725-01

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Allied Air Enterprises A95DF, 92G1DF, A93DF, 95G1DF Air from Outside, Equipment in Confined Space − ALL AIR from Outside
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A95DF, 95G1DF, A93DF, 92G1DF specifications

Allied Air Enterprises offers a range of high-efficiency commercial and residential heating and cooling systems, with models like the 92G1DF, A93DF, 95G1DF, and A95DF gaining popularity for their cutting-edge technology and advanced features. Each of these models stands out in performance, reliability, and energy efficiency, making them excellent choices for diverse applications.

The 92G1DF model features a multi-stage gas valve that enhances temperature regulation, allowing for more precise heating. With an impressive Annual Fuel Utilization Efficiency (AFUE) rating, this furnace efficiently utilizes fuel, resulting in lower energy costs and reduced emissions. Its compact design makes it suitable for installations in tight spaces, while the durable heat exchanger extends the unit’s lifespan.

In contrast, the A93DF is engineered for enhanced comfort and flexibility. This model incorporates a variable-speed blower motor, which adjusts air circulation according to the heating demands in the space. This feature not only maximizes comfort by providing consistent temperatures but also promotes energy savings by reducing unnecessary power consumption. Additionally, the A93DF includes advanced diagnostic capabilities that simplify troubleshooting and maintenance, making it a favorite among HVAC professionals.

The 95G1DF is another noteworthy model that combines versatile performance with exceptional efficiency. This furnace boasts an AFUE rating of up to 95%, making it one of the most efficient models in its class. Its innovative design includes a secondary heat exchanger that captures additional heat from exhaust gases, optimizing energy utilization. Furthermore, the 95G1DF is equipped with an advanced control system that allows homeowners to set specific comfort levels.

Lastly, the A95DF model takes efficiency to a new level. With features such as a modulating gas valve and a variable-speed blower, this unit seamlessly adapts to changing heating needs. The A95DF not only heats a space but also enhances air quality through advanced filtration options. Its whisper-quiet operation adds to user satisfaction, making it ideal for residential settings.

In summary, Allied Air Enterprises' models 92G1DF, A93DF, 95G1DF, and A95DF demonstrate a commitment to innovation and energy efficiency, with features designed to provide superior comfort and reliability. With their advanced technologies and high-performance characteristics, these models are positioned as top contenders in the heating and cooling marketplace, ensuring that customers can enjoy a comfortable environment year-round.
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