Lenoxx Electronics Optima 3 FS operation manual Floor Protection / Hearth Extension Using

PLANNING YOUR INSTALLATION

FLOOR PROTECTION - Optima 3 FS
The floor protector must						Top View
meet	or	exceed		the
						*Up to 6”
minimum		thermal		re-	1
quirements as			defined			53 mm minimum
on this page (see Floor
Protection/Hearth				Ex-
tension Using Alternate
Material As Floor Pro-
tector). If the floor				pro-	153mm6”/	6”/
tection	is	to be	stone,			153mm
tile, brick,		etc.,	it	must	min.	min.
be mortared or grouted
to form		a continuous
noncombustible				sur-
face. If a chimney con-						6”/153mm
nector extends horizon-
tally over the floor, pro-						minimum

tection must also cover

the floor under the connector and at least 2" (51 mm) to either side.

The floor protector must fully cover the area beneath the appli- ance and extend 6” to the front, 6” to the sides, and 6” from the back as shown in the illustration to the right (Note: When installed at clearances less than 6”, the floor protection is only required to extend to the wall).

TM (inches) = kM x TL

.84

TM (inches) = 1.92 x .375 (3/8”)

.84

Answer using k: 2.29 x 0.375” = 0.858 = ~7/8”

7/8” thickness (minimum) Durock Cement will be required. Using the r formula:

TM (inches) = 1.19 x TL rM

TM (inches) = 1.19 x 375 (3/8”)

.52

Answer using r: 2.29 x 0. 375” = 0.858 = ~7/8”

7/8” thickness (minimum) Durock Cement will be required.

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

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

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 .375” = .45.

Listed Material

FLOOR PROTECTION / HEARTH EXTENSION USING								Thermal Values		Specified
ALTERNATE MATERIAL AS FLOOR PROTECTOR (also										Minimum
see Floor	Protection above for freestanding models and									Thickness
							k (per inch)		r (per inch)	TL
Hearth Requirements, page 8 for the insert model)
						Listed Material →	.84		1.19	3/8” (.375)
The hearth pad or alternate material used as a floor/hearth
protector must be constructed of a durable noncombustible						Approved Alternate Materials for
material having an equal or better thermal conductivity value
(lower k value) of k = .84 BTU / IN FT2 HR °F or a thermal						Floor/Hearth Protection (**)
resistance that equals or exceeds r = 1.19 HR °F FT2 IN/BTU						Alternative		Thermal Values		* Minimum
with a minimum thickness of 3/8”. With these values, deter-						Materials ↓				Thickness
mine the minimum thickness of the alternate material required								k (per inch)	r (per inch)	TM
using the formula(s) and the table shown here (see chart -						Kaowool M Board		.47	2.13	* 3/8”
Approved Alternate Materials for Floor/Hearth Protection).
						Micore 160		.35	2.86	* 3/8”
Note: Any noncombustible material having a minimum thickness						Micore 300		.46	2.18	* 3/8”
of 3/8” (10 mm) whose k value is less than .84 or whose r value						Durock Cement		1.92	.52	7/8”
is more than 1.19 is acceptable. If the alternate material used has						Hardibacker		1.95	.51	7/8”
a higher k value or lower r value will require a greater thickness of
						Hardibacker 500		2.30	.44	1 1/8”
the material used. In some cases, if the k value is less or the r
						Cultered Stone		2.82	.35	1 5/8”
value higher, a thinner material may be used.						Hearthstone
Methods of determining floor protection equivalents:						Wonderboard		3.23	0.31	1 1/2”
To determine the thickness required for the alternate material						Face brick		9.00	0.11	4 1/8”
when either the k value or r value is known, use either the k						Common brick		5.00	0.20	2 1/4”
formula or r formula:
						Cement mortar		5.00	0.20	2 1/4”
		Cement is to be used for the floor protec-				Ceramic tile		12.5	.08	5 5/8”
Example: Durock
tion. How thick must this material be? The following formulas						Marble		~20.0	~.05	9”
give the means of determining minimum thickness required.						Note: To convert inches to millimeters divide by .03937.
TM = minimum thickness required for alternate material
						* After minimum thickness is calculated, the thickness can be
kM = k value per inch of alternate material
TL = minimum thickness of listed material						no less than 3/8” (.375” / 10mm).
rM = r value per inch of alternate material						(**) If the floor protector to be used is a noncombustible material
Using the k formula:						and is NOT listed on the chart above, the manufacturer of the ma-
Minimum		k-value (per Inch)		Specified min.		terial must provide either the listed k-value per inch or r-value per
						inch and the minimum acceptable thickness will need to be calcu-
thickness of	=	of alternate material	x	thickness
alternate		k-value (per inch)		of listed		lated per instructions on this page.
material		of listed material		material	.

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