Thermo Products MDA1-50N, MHA1-75N Standard Clearances, Refer to Figure, Non-combustible Material

All installations and services must be performed by qualified service personnel.

and MDA1-75; 100CA-BASE for MDA1-100; and 125CA-BASE for MDA1-125.

refer to Figure 1.

Figure 1: Counter flow Furnace Combustible Surface-Mounting Base

D. Standard Clearances

Definitions of combustible material and non-combustible as issued by the National Fuel Gas Code are as follows:

Combustible Material:

Materials made of or surfaced with wood, compressed paper, plant fibers, plastics or other material that will ignite and burn whether flameproof or not or whether plastered or not plastered.

Non-combustible Material:

Material which will not ignite and burn; such materials consisting entirely of steel, iron, brick, concrete, slate, glass, plaster or combination thereof.

Table 1: Minimum Clearances to Combustible Materials

	Sides & Rear	Front of	Top of		Sides of
Model No.	of Furnace	Furnace	Plenum	Flue or Vent	Plenum
	(in.)	(in.)	(in.)	(in.)	(in.)
All Models
Covered by	0	6	1	*6	1
This Manual

*6 in. clearance may be reduced to 1 in. with UL Recognized type B1 vent.

The minimum clearances are listed for fire protection. Clearances for servicing and proper operation, the front of the furnaces and to all points on the furnace requiring access must be 24 in.

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