Lennox Hearth T150C operation manual Floor Protection, USA Requirements, Canada Requirements

PLANNING YOUR INSTALLATION

FLOOR PROTECTION

This appliance requires ½" (13 mm) minimum non- combustible floor protection designed for solid fuel burn- ing appliances having a thermal conductivity of k = .84 BTU in/ft or equivalent. If the floor protection is to be stone, tile, brick, etc., it must be mortared or grouted to form a continuous non-combustible surface (See Using Alternate Material As Floor Protector below). If a chimney connector extends horizontally over the floor, protection must cover the floor under the connector and at least 2" (51 mm) to either side.

The floor protection must extend completely beneath the stove and to the front, sides, and rear as indicated:

USA REQUIREMENTS

16” min. to the front of the fuel door glass

8” min. beyond the sides of the fuel door opening 6” min. to the back of the stove body

CANADA REQUIREMENTS

18” (457 mm) min. to the front of the fuel door glass 8” (203 mm) min. beyond the sides of the stove body 8” (203 mm) min. to the back of the stove body

STANDARD PARALLEL HEARTH PAD SHOWN

	6” - USA
	8” – Can.
8” (203 mm)		8” (203 mm)
Canada		Canada
8” (203 mm)		8” (203 mm)
USA
		USA
	18” (457 mm) – Canada
	16” (406 mm) - USA

USING ALTERNATE MATERIAL AS FLOOR PROTECTOR The alternate material used as a floor protector must be constructed of a durable noncombustible material having an equal or better insulating value (lower k value) of k = .84 BTU / IN FT2 HR °F or a thermal resistance that equals or exceeds r = 1.19 HR °F FT2 IN/BTU. With these values, de- termine the minimum thickness/material required using the formula and the table shown here (see chart - Alternative Floor Protection Materials).

Note: Any noncombustible material having a thickness of 1/2” (12.7 mm) whose k value is less than .84 or whose r value is more than 1.19 is acceptable. If the alternate material used has a higher k value or lower r value will require a greater thickness of the material used. In some cases, if the k value is less or the r value higher, a thinner material may be used.

Methods of determining floor protection equivalents:

To determine the thickness required for any material when either the k or r values are known:

TM = Thickness of material in inches KM = K value of desired material TL = Minimum listed thickness

rM = r value of desired material

Example: Micore CV230 is to be used for the floor pro- tection. How thick must this material be?

The following formulas give the means of determining minimum thickness required of alternate materials.

Using the k formula:

Desired Thickness		k value of desire	Minimum thickness
of the alternate	=	material (per inch) x	of Listed
material		k value of listed	Material
		material (per inch)
TM (inches) =	KM	x TL
	.84
TM (inches) =	0.43* x 1/2”
	.84

Answer using k: 0.50 x 0.50” = 0.25 = 1/4” 1/4” thickness Micore will be required.

Using the r formula:

TM (inches) = 1.19 x TL rM

TM (inches) = 1.19 x .5” 2.33*

Answer using r: 0.50 x 0.50” = .25 = 1/4” 3/8” thickness Micore will be required.

At times it is important to know what combination of ma- terials are acceptable for use as floor protection. The “R values” are used to determine acceptable combinations of materials because “R values” are additive where r and k values are not.

“R value” = 1 = r x thickness of material used k

ALTERNATIVE FLOOR PROTECTION MATERIALS

	Values		Min. Thick
	k (per inch)	r (per inch)	TL
Listed Material	.84	1.19	1/2”
Alternative	Values		Min. Thick
Materials	k (per inch)	r (per inch)	TL
Wonderboard	1.92	0.56	1 1/8"
Common brick	5.00	0.20	3”
Cement mortar	5.00	0.20	3”
Ceramic tile	12.5	0.08	7 1/2”
Marble	11.0	0.09	6 1/2”
Micore CV230	0.43	2.33	1/4”
Ceraform 126	0.27	3.70	3/16”

Example: Given that the required “R value” for a suitable floor protector used must be equal to or greater than:“R” = r x TL = 1.19 x .5” = .60.

Note: To convert inches to millimeters divide by .03937.

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