Air For Combustion Residential | Mr. Heater MHT 45 instruction

Vertical Venting

Air For Combustion (Residential)

If indoor combustion air is to be supplied for a tightly enclosed area, one square inch of free area opening shall be provided below the heater for each 1,000 Btu/hr of heater input.

When outside air is used, the opening below the heater shall be one square inch of free area for each 4,000 Btu/hr of heater input. In contaminated atmospheres or high humidity areas, optional outside air for combustion is recommended.

Adequate clearances around the perforated fresh air plate must be maintained at all times. In larger open areas of buildings, infiltration normally is adequate to provide air for combustion.

Direct Outside Air For Combustion (Residential)

Outside combustion air should be supplied directly to the heater when the building is subject to negative pressure or contaminants are present in the building air. These contaminates include paints, solvents, corrosive vapors or any other foreign particles that may cause damage to the heater or result in poor combustion.

Outside combustion air can be brought directly to the heater by a 3 inch diameter duct less than 25 feet long or equivalent. This is attached to a 3 inch starting collar that is fitted on inlet side of the control cabinet. An approved vent cap must be placed directly to the end of the outside combustion air inlet pipe. The combustion air inlet should be a minimum of 3 feet, either vertically or horizontally, from the flue vent termination. The air intake terminal must be located not less than one foot above grade. It is good installation practice to supply combustion air from the same pressure zone as the vent outlet.

In colder climates, where necessary, insulate the fresh air duct. Avoid locating the fresh air duct directly above the control box. Provide a capped cleanout T as necessary.

VERTICAL THROUGH THE ROOF

Vent Cap

(Leslie VersaCap)

	3" Dia.
3' Min.	Single-Wall Pipe

6" Min.

Flashing
3" Starting Collar	¼” per ft.
	downwards

Intake Vent

Outside Combustion Air Supply

The MHT tube heater is approved for installation with an outside air supply system. Some compounds such as halogenated hydrocarbons or other corrosive chemicals in the air can be drawn into the equipment and cause an accelerated rate of corrosion of some of the heater components. The use of such chemical compounds near the enclosure should be avoided.

IMPORTANT: If the building has a slight negative pressure or contaminants are present in the air, an outside combustion air supply to the heaters is strongly recommended.

For an outside air supply a three (3") inch O.D. single wall pipe may be attached to the heater. The duct may be up to twenty five (25') feet maximum length or two (2') feet minimum length with no more than two (2) elbows.

The air supply duct may have to be insulated to prevent condensation on the outer surface. The outside air terminal should be securely fastened to the outside wall by drilling four (4) holes in the outside flange; wood screws or bolts and expansion sleeves may be used to fasten terminal.

Non-Pressurized Outside Air Supply Duct

Mr. Heater Gas-Fired Low-Intensity Infrared Heater

Operating Instructions and Owner’s Manual

MHT 45 specifications

The Mr. Heater MHT 45 is a versatile and powerful heating solution designed for both residential and commercial spaces. This portable propane heater stands out in the market due to its efficient heating capabilities and user-friendly features, making it ideal for workshops, garages, and outdoor activities.

One of the standout features of the MHT 45 is its robust heating output. It can deliver an impressive 45,000 BTUs, ensuring that even larger spaces are heated quickly and effectively. This high output is particularly beneficial during colder months, where rapid warmth is essential for comfort and productivity. The heater offers a heating range of up to 1,000 square feet, making it suitable for various applications, whether in the home or on the job site.

The MHT 45 utilizes advanced radiant heating technology, providing even warmth without requiring a fan. This technology allows for silent operation, making it an excellent option for noise-sensitive environments. Additionally, the radiant heat minimizes air movement and helps maintain humidity levels, creating a comfortable atmosphere while reducing dust and allergens in the air.

Another noteworthy characteristic is its portability. The MHT 45 comes equipped with a sturdy handle, allowing for easy transport between locations. This makes it a favorite among tradespeople who need efficient heat in different work areas or outdoor enthusiasts who want comfort while camping or tailgating.

Safety features are abundant in the Mr. Heater MHT 45. It includes an automatic shut-off system, which activates if the heater tips over, ensuring user safety. The built-in oxygen depletion sensor automatically turns the heater off if it detects low oxygen levels in the surrounding environment, providing peace of mind while operating.

The heater runs on a 20-pound propane tank, providing a substantial amount of heating time before needing a refill. This efficiency means users can rely on the MHT 45 for extended periods without frequent interruptions.

In summary, the Mr. Heater MHT 45 is a powerful propane heater packed with features that cater to both indoor and outdoor heating needs. With its high BTU output, silent operation, portability, and extensive safety measures, it represents a reliable choice for anyone looking to stay warm in various settings. Whether for personal use or demanding job sites, the MHT 45 is engineered to deliver comfort and convenience.