Downflow Installation

Downflow unit installs in three ways: on non−combustible flooring, on combustible flooring using a downflow com- bustible flooring base, or on a reverse−flow cooling cabinet. Do not drag the unit across the floor.

Installation on Non−Combustible Flooring (Figure 6)

1 − Cut floor opening keeping in mind clearances listed on unit rating plate. Also keep in mind gas supply connec- tions, electrical supply, flue and air intake connections and sufficient installation and servicing clearances. See table 1 for correct floor opening size.

2 − Flange warm air plenum and lower the plenum into the opening.

3 − Set the unit over the plenum and seal the plenum to the unit.

4 − Ensure that the seal is adequate.

SL280DFV UNIT
OPENING	SUPPLY AIR
OPENING	PLENUM

FIGURE 6

TABLE 1

NON−COMBUSTIBLE FLOOR OPENING SIZE

	Front to Rear		Side to Side
Cabinet Width
Cabinet Width	in.	mm	in.	mm
	in.	mm	in.	mm


A (14.5")	19−3/4	502	13−1/4	337
B (17.5")	19−3/4	502	16−1/4	413

C (21")	19−3/4	502	19−3/4	502

NOTE − Door opening dimensions listed are 1/4 inch (6 mm) larger than the unit opening. See unit dimensions on page 2.

Installation on Combustible Flooring (Figure 7)

1 − When unit is installed on a combustible floor, a down- flow combustible flooring base must be installed be- tween the furnace and the floor. The base must be or- dered separately.

See table 2 for opening size to cut in floor.

CAUTION

The furnace and downflow combustible flooring base shall not be installed directly on carpeting, tile, or other combustible material other than wood floor- ing.

	SL280DFV UNIT
		SUPPLY AIR PLENUM
	PROPERLY	DOWNFLOW
	PROPERLY	COMBUSTIBLE
	SIZED FLOOR	COMBUSTIBLE
	SIZED FLOOR	FLOORING BASE
	OPENING	FLOORING BASE
	OPENING

FIGURE 7

TABLE 2

COMBUSTIBLE FLOOR OPENING SIZE

	Front to Rear		Side to Side
Cabinet Width
Cabinet Width	in.	mm	in.	mm
	in.	mm	in.	mm


A (14.5")	22	559	15−3/4	400

B (17.5")	22	559	18−3/4	476

C (21")	22	559	22−3/4	578

NOTE − Floor opening dimensions listed are 1/4 inch (6 mm) larger than unit opening. See unit dimensions on page 2.

2 − After opening is cut, set combustible flooring base into opening.

3 − Check sealing strips on combustible flooring base to make sure they are properly glued and positioned.

4 − Lower supply air plenum into downflow combustible flooring base until plenum flanges seal against the strips.

NOTE − Be careful not to damage sealing strips. Check for a tight seal.

5 − Set the furnace over the plenum.

6 − Ensure that the seal between the furnace and plenum is adequate.

Installation on Cooling Cabinet (Figure 8)

1 − Refer to reverse−flow coil installation instructions for correctly sized opening in floor and installation of cabi- net.

NOTE − Downflow combustible flooring kit is not used

2 − When cooling cabinet is in place, set and secure the furnace according to the instructions that are provided with the cooling coil. Secure the furnace to the cabinet.

3 − Seal the cabinet and check for air leaks.

Page 9

DAVE LENNOX SIGNATURE COLLECTION GAS FURNACE, SL280DFV specifications

Lennox International Inc has made a significant mark in the heating, ventilation, and air conditioning (HVAC) industry, known for its commitment to innovation and energy efficiency. One of its standout products is the SL280DFV model, a high-efficiency gas furnace designed to meet the needs of modern homes.

The SL280DFV boasts an impressive Annual Fuel Utilization Efficiency (AFUE) rating of up to 80%. This rating indicates that the furnace converts 80% of the fuel it consumes into usable heat, making it a cost-effective choice for homeowners. The high efficiency not only reduces energy bills but also lessens the environmental impact by minimizing greenhouse gas emissions.

One of the key features of the SL280DFV is its two-stage gas valve operation. This technology allows the furnace to operate at two levels of heating output: low stage for milder days and high stage for extremely cold temperatures. This adaptability enhances comfort by maintaining more consistent indoor temperatures while also saving energy when full power is unnecessary.

Another innovative aspect of the SL280DFV is its variable-speed blower motor. This smart technology enables the furnace to adjust airflow based on the heating needs of a home, which promotes quiet operation and improved temperature consistency throughout living spaces.

The SL280DFV is equipped with a durable heat exchanger that is designed to withstand the rigors of daily use, contributing to the unit’s longevity. Additionally, the furnace features a smart ignition system that ensures reliable start-ups, so homeowners can depend on it through the coldest winter nights.

Safety is also a priority in the design of the SL280DFV. It includes various safety features such as a built-in flame sensor and advanced venting system, designed to avert hazardous situations and ensure optimal operation.

Furthermore, Lennox offers convenient installation and maintenance support, making the SL280DFV not only an efficient heating solution but also a practical choice for homeowners. With its blend of advanced technology, high efficiency, and reliability, the Lennox SL280DFV is an appealing option for those looking to upgrade their home’s heating system, promising comfort and peace of mind for many winters to come.

Lennox International Inc DAVE LENNOX SIGNATURE COLLECTION GAS FURNACE Downflow Installation

Models: DAVE LENNOX SIGNATURE COLLECTION GAS FURNACE SL280DFV