Restroom Calculator

Need an estimate for how many porta potties your event needs? Use this handy calculator! For a more specific quote tailored to your needs, call us today at 800-210-8407!

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Portable Heat Calculator

Need an estimate for how many BTU's you'll need to heat up your space? Use this handy calculator! For a more specific quote tailored to your needs, call us today at 800-210-8407!

Heating Calculator
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Direct Fired Heaters

Efficient Vapor Propane or Natural Gas Heating

Benefits of Direct Fire Heating

Direct fired heaters are very much like your typical gas grill or stove top, in which a propane tank or other type of natural gas forces air directly through a flame to heat the air. Direct fired heaters are a great addition to any outdoor party in the fall, winter or early spring, as well as construction sites or disaster relief. What are some of the benefits to direct fire heaters? Here are just a few:


First off, the main benefit to using a direct fire heater is the efficiency it provides. As a fuel heater, they convert 100 percent of the fuel being used to heat which lowers fuel consumption and operating costs. This is great if you’re using a heater all day long at a construction site and are trying to keep energy costs down.


High amounts of heat (BTU’s) are produced in smaller units when compared to indirect fire heaters. OnSite provides heaters that supply 400,000 BTU’s all the way up to 4,000,000 BTU’s. Now that is power!

Easy to Move

Because they are on wheels and portable, direct fired heaters are pretty easy to set up, move around and turn off when heat is not needed. All it takes is some simple knowledge and common sense to use one of these types of heaters. A few of OnSite’s heaters are also small enough to be moved by one person, requiring less manpower to get heat where you need it.

Lower Energy Cost

Direct fired heaters are lower cost than other types of heaters, meaning you can pump out heat all day long without compromising your budget. If you’re looking for a cost-effective way to boost the temperature in your job site, business or work area, direct fired heaters are the way to go.

Safe for Everyone

Numerous safety features give power to the user, allowing the heaters to stay running without oversight. If you’re throwing a party outdoors, or working a construction site during the winter, the last thing you need to worry about is heater upkeep. With direct fired heaters, even the most novice user can have steady heat flowing all day long.

Lower Maintenance Costs

Unlike indirect fired heaters, direct fired heaters are easy to maintain and a simple way to provide heat. Because all it takes is a full propane tank, many times if your heat runs out, the only thing you need is more gas. A quick stop at the gas station or hardware store to refill your tank is all the maintenance that’s required on most direct heater models.

Built in Thermostat

On many direct heater models, a thermostat is displayed to inform the user on what the temperature is. This helps control the climate and temperature, giving the worker the option to turn it off when the temperature reaches the perfect point.


The 950H Direct Fire Heater, provided by On Site Companies, can provide your home, business or job site with the heating capabilities that you require. This heater is equipped with a cast iron and stainless steel burner that will work through extreme weather all year round. With flame safeguard control and self-diagnostic L.E.D. lights, you can be easily notified if your unit is not operating at the correct capacity. The 950H’s light weight design is ductable up to 50’ to provide heat directly where you need it.

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S405 Direct Fired Heater

The S405 Portable Direct Fired Heater, provided by On Site Companies is the smallest direct fired heating solution that we provide. This portable heater is CSA Approved for unintended use, which makes it easy to keep your job site warm. It is also light enough so only one person is needed for operation. It is designed for use on construction sites and has a thermostat to help conserve fuel.

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S1505 Direct Fired Heater

The S1505 Portable Direct Fired Heater, provided by On Site Companies, is an efficient direct fired heater that can meet the needs of large job sites or homes. This heater is designed to use less amp draw, which allows it to run on a 15 amp circuit. The updated heater control board also allows you to start the heater with as few as 95 volts and can run stable when voltage drops below 83 volts. With the cold winters in the Mid-West, you can also be assured that this heater can run in temperatures as low as -40F.

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3050 Direct Fired Heater

The 3050 Portable Direct Fired Heater, provided by On Site Companies, is a great tool for a large and busy job site. The 3050 heater has many safeguards in place to make sure that nothing goes wrong with the equipment. For instance, if the combustion air is interrupted, the 3050 will automatically shut down the system. It also shuts down if the product is being over fired. The heat can also be ducted up to 300 feet from where the equipment is stationed.

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1801 Direct Fired Heater

The 1801 Portable Direct Fired Heater, provided by On Site Companies, will equip your home, business or job site with the heat that you require to be comfortable and efficient. This AGA Certified unit has an air flow switch, burner heat shield and flame safeguard control to ensure safety and efficiency during use. With dual fuel capabilities, you will also have more options on how to run your equipment. The 1801 also has a hi limit switch, panel mounted thermostat and weather sealed control box for optimal usage during the colder months.

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On Site Companies heat branch offers a full range of direct fired portable heaters available for rent. These heaters are perfect for temporary use at locations where you need to leave heating units unattended for periods of time. On Site Companies inventory can provide your commercial job site with heating solutions that will improve working conditions and work quality. Through pressurized methods, direct fired heaters will rapidly heat large spaces and forces moisture and contaminates outside. No other system can match this type of heater for ease of use and cost effectiveness. These heaters are perfect for use on your construction site or commercial area.All burn 100% outside air.

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