Confined Space

A confined space is an area with a volume less than 50 cu- bic feet (1.42 m3) per 1,000 Btu (.29 kW) per hour of the combined input rating of all appliances installed in that space. This definition includes furnace closets or small equipment rooms.

When the furnace is installed so that supply ducts carry air circulated by the furnace to areas outside the space contain- ing the furnace, the return air must be handled by ducts which are sealed to the furnace casing and which terminate outside the space containing the furnace. This is especially important when the furnace is mounted on a platform in a confined space such as a closet or small equipment room. Even a small leak around the base of the unit at the platform or at the return air duct connection can cause a potentially dangerous negative pressure condition. Air for combustion and ventilation can be brought into the confined space either from inside the building or from outside.

EQUIPMENT IN CONFINED

SPACE ALL AIR FROM INSIDE

CHIMNEY

OR GAS

VENT

 

WATER

FURNACE

HEATER

 

OPENINGS

 

(To Adjacent

 

Room)

NOTE − Each opening shall have a free area of at least one square inch (645 mm2) per 1,000 Btu (.29 kW) per hour of the total input rat- ing of all equipment in the enclosure, but not less than 100 square inches (64516 mm2).

FIGURE 2

Air from Inside

If the confined space that houses the furnace adjoins a space categorized as unconfined, air can be brought in by providing two permanent openings between the two spaces. Each opening must have a minimum free area of 1 square inch (645 mm2) per 1,000 Btu (.29 kW) per hour of total input rating of all gas−fired equipment in the confined space. Each opening must be at least 100 square inches (64516 mm2). 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. See figure 2.

Air from Outside

If air from outside is brought in for combustion and ventila- tion, the confined space must have two permanent open- ings. 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 di- rectly or by ducts with the outdoors or spaces (crawl or at- tic) 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 en- closure. See figures 3 and 4. 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 5.

When ducts are used, they shall be of the same cross−sec- tional 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 cov- ering is not known for calculating the size opening required, it may be assumed that wood louvers will have 20 to 25 per- cent 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.

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Lennox International Inc EL280DF installation instructions Equipment in Confined Space ALL AIR from Inside
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EL280DF specifications

Lennox International Inc. has been a leader in the HVAC (Heating, Ventilation, and Air Conditioning) industry for decades, consistently delivering high-quality and energy-efficient products. Among their lineup, the Lennox EL280DF Gas Furnace stands out as an excellent option for homeowners seeking reliable heating solutions.

The EL280DF is a two-stage gas furnace that offers improved efficiency and comfort, making it an ideal choice for moderate climates. One of the main features of the EL280DF is its energy efficiency, boasting an AFUE (Annual Fuel Utilization Efficiency) rating of up to 80%. This means that a significant portion of the fuel consumed is converted into heating energy, resulting in lower energy bills and reduced environmental impact.

Another noteworthy characteristic of the EL280DF is its quiet operation. Equipped with advanced sound-dampening technologies, the furnace operates with minimal noise, ensuring that your home remains a serene environment. This is especially important during the colder months when the furnace is often in frequent use.

The EL280DF also employs a two-stage heating system, which allows it to operate at a lower capacity during milder temperatures and ramp up to full capacity during the coldest days. This feature not only enhances comfort by maintaining a more consistent temperature but also contributes to energy savings by reducing unnecessary energy consumption.

In terms of installation, the EL280DF is designed for flexibility. It can be configured for various types of homes and installations, making it suitable for both new constructions and system replacements. Its compact size allows it to fit in tight spaces, providing versatility in home design.

Moreover, the EL280DF is equipped with a durable heat exchanger that ensures longevity and reliability. Lennox has also included features like a self-diagnostic control board, making troubleshooting easier and enhancing the overall reliability of the system.

In conclusion, the Lennox EL280DF Gas Furnace is a remarkable combination of efficiency, quiet operation, and versatility. With its two-stage heating capabilities and advanced technologies, it stands as a solid choice for homeowners looking to invest in a durable and energy-efficient heating solution. Whether building a new home or upgrading an old system, the EL280DF promises comfort and reliability during the coldest months of the year.
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