The Mr. Heater Portable 35K Forced Air Propane heater offers efficient temporary heat for construction sites, agricultural buildings, industrial workspaces, remodeling jobs and more. Features a high-output fan to maximize air circulation, 10-ft. hose and regulator (tank sold separately). High-temperature limit switch/flame safety. Compact and lightweight with attached carrying handle. CSA certified.
The MH125FAV is the least powerful of Mr. Heater’s line of propane forced-air heaters for smaller jobs (see the MH55FAV and the MH85FAV). The heater gives you 35,000 Btu–enough to heat 800 square feet. Though the larger models give you more Btus, each heater in the line shares the same basic features, including an automatic shutoff with loss of flame or power supply and a high-output fan that circulates heat quickly. Hooking the heater up to the 20-pound propane cylinder (not included) is easy, and the 10-foot hose and regulator are included. CSA certified. One-year limited warranty.–Josh Dettweiler
What’s in the Box
Heater (heater body kit, control box assembly, valve with thermocouple, wire assembly, electrode, high limit switch [240 degrees F], thermocouple, motor 0.74 A, grille assembly, fan blade, 6.75 x .75 pitch, power, cord assembly, strain relief bushing, piezo ignitor, clip handle, handle), 10-foot hose, regulator, operating instructions and owner’s manual
Five Tips for Buying a Heater
Choosing a space heater is a matter of sifting through a bewildering array of types, power ratings, and fuel sources. Let’s break it down a little to make the process easier.
What are the different types of space heaters?
- Radiant heaters emit infrared radiation that directly warms the objects in front of the heaters (rather than the surrounding air). If you only need heat by a desk or in a small section of a room, a radiant heater is quiet and will use very little power.
- Forced-air heaters use a fan to blow air that has been warmed by metal or ceramic heating elements. A forced-air heater is appropriate for quickly heating up a small- to medium-sized room, but can be noisy.
- Convection heaters draw cold air from the floor; the air is warmed by heating coils and emitted from the top of the heater. A convection heater is appropriate for quickly heating up a small- to medium-sized room, but also can be noisy.
- Radiators work by heating oil enclosed in a reservoir, gradually heating the surrounding air. If heating speed isn’t an issue, you might want to opt for a radiator. These are extremely quiet and effective–perfect for bedrooms.
Should I buy an electric or a combustion model?
If you want a heater that will be available in emergencies, or that can heat areas larger than a single room, choose a “combustion” model–one that is powered by a gas or fuel like propane, kerosene, natural gas, or diesel. Which fuel type you choose depends largely on convenience and local availability. For example, diesel would be appropriate for a heater you take with you on long car trips.
How powerful a heater do I need?
Heaters are rated by BTU, which stands for British Thermal Unit (the amount of heat needed to heat one pound of water by 1 degree F). To find out how many BTU you need:
- Calculate the volume of the space to be heated by multiplying square footage by height.
- Multiply that number by 4 if your insulation is poor, 3 if it’s average, or 2 if it’s good.
The resulting number is a ballpark figure for how many BTU you’ll need.
Do space heaters cost a lot to operate?
As a general rule, electric space heaters are more expensive to use than combustion models. To ensure energy efficiency, a thermostat is a must-have feature for any heater. For radiant heaters, models with a 360 degree heating surface can heat larger spaces. If you need a forced-air heater, models with ceramic elements tend to be more efficient.
Are space heaters a fire hazard?
Space heaters are implicated in about 25,000 residential fires every year. To ensure proper safety, always follow the manufacturer’s usage instructions and fill out the warranty card to receive informational updates from the manufacturer. Also, look for extra safety features such as an automatic shutoff switch that can shut down the unit if, for example, it gets upended. In addition, choose a model where the heating element is adequately enclosed within the unit.
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35,000 Btu forced-air propane heater
Ideal for smaller industrial/commercial workspaces; heats up to 800 square feet
Runs up to 12 hours
Requires 20-pound propane tank (not included); 10-foot hose and regulator included
Adequate combustion and ventilation air must be provided; 1-year limited warranty