321 Studios FLR085D36E, FLF110D48E, FH110D48E Typical Installation of FR26 FR27 Filter Racks

AIR FILTERS

Only Lo-Boy models are shipped with air filters. Filter kits are available from your local distributor for Upflow and Counterflow models. Knockouts are provided in the sides of the FH series models to facilitate the cutting of the return openings.

The upflow filter kit part numbers are FR23 for a 16x25x1 filter size and FR24 for a 20x25x1 filter size. These filter kits come complete with the filter and all necessary brackets for installing on the furnace. Each comes with a washable aluminum mesh filter. When installing a five ton AC unit on the furnace, one FR24 or Two FR23 must be used due to the high airflow requirements. It is important to note that a minimum of one inch spacing is required between the filter and the unit side. Do not exceed 400 fpm for fiberglass (disposable) type filters and 575 fpm for washable type filters. See Figure 16.

The counterflow filter kit part number FR25 comes with two washable filters. If not installing the FR25 kit remember not to exceed 400 fpm for fiberglass (disposable) type filters and 575 for washable type filters. See Figure 17.

See Table 11 for filter sizes and quantities.

FIGURE 16

TYPICAL INSTALLATION OF FR26 AND

FR27 FILTER RACKS

19 1/4"

16"

	Filter
(2) screws	Frame
	Filter
Filter	MIS-1839 A
Door

TABLE 11

FILTER SIZES FOR OIL FURNACES

Model		Size
FH085D36E	(1)	16 x 25 x 1
Hi-Boy
FH110D48E	(1)	16 x 25 x 1
Hi-Boy
FH110D60E	(1)	20 x 25 x 1
Hi-Boy
FLF085D36E
FLR085D36E	(1)	16 x 20 x 1
Lo-Boys
FLF110D48E
FLR110D48E
FLF110D60E	(1)	20 x 20 x 1
FLR110D60E
Lo-Boys
FLR140D60E	(1)	20 x 25 x 1
Lo-Boy
FC085D36E	(2)	16 x 20 x 1
Counterflow

FIGURE 17

TYPICAL INSTALLATION OF FR25

FILTER KIT

Optional

Filter

Box

"FC" Unit

70 5/16"

MIS-1841

Manual 2100-422 Page 27