Does your project need a heater? Whether you need a heater to keep your employees warm, safe, happy, and productive, or you need it to decrease drying time of a job, you’re going to need to make a decision: Is a direct fired or indirect fired heater right for your job? We’re here to help you make that decision, because understanding the difference between these two types of heaters is crucial in choosing the correct heating system for your project.
In short, a direct fired heater forces air through the flame to heat the air making it 100% fuel-efficient, while an indirect fired heater’s flame is in a burn chamber, which heats up a heat exchanger. The cool air passes over the heat exchanger in turn heating the air and losing efficiency in exchange for clean air.
Direct fired heaters
Direct fired heaters are similar to gas stovetops and work by using fuel to heat the air. To achieve this, an open flame inside the unit warms incoming air before it is exhausted, delivering a vast amount of heat output quickly. This makes them fuel efficient, but, due to the carbon dioxide output as a result of the combustion, proper ventilation is required for safety. Location and ventilation of your job site are important factors when considering if a direct fired heater is the right choice for your project. Here are key features about this type of heating system to further inform your decision-making process.
Benefits of direct fired heaters:
- Efficiency – 100% of the fuel is converted into heat lowering fuel consumption and operating costs
- Easy to transport – these units have a simple design and can easily be moved to where heat is required
- Lower rental costs and maintenance costs
Drawbacks of direct fired heaters:
- Ventilation required – Doors, windows, and open spaces required to maintain a healthy work environment
- Safety concerns – Moisture and carbon monoxide released into the air
Indirect fired heaters
An indirect heater is just like a home oil or gas burning furnace with a chimney. It is ventilated to keep combustion byproducts, such as carbon dioxide, out of the air and can therefore be utilized in enclosed spaces. Because the heated air is ventilated away from the breathable air, the heater is not emitting combustion byproducts into the workspace, but it is not as easy to set-up due to the required chimney or ducting. Here are key features about this type of heating system to further inform your decision-making process.
Benefits of indirect fired heaters:
- Clean air – The air being circulated never comes into contact with the flame and stays clean
- Thermostats – Most indirect fired heaters use a thermostat
- Can be used in enclosed spaces – Carbon dioxide is not released into the space being heated
Drawbacks of indirect fired heaters:
- Higher cost – Rental cost is more than a direct fired heater
- Lower efficiency – Fuel efficiency is lower due to the air not being directly heated by the flame
- Electricity required – Indirect fired heaters require an electrical outlet
Which is right for you?
You’ll need to consider multiple factors when deciding if you need a direct fired heater or an indirect fired heater including cost, location, reason for needing a heater, and ease of setup. Indirect fired heaters are perfect for a tightly sealed workspace such as a retail space, construction sites, and healthcare buildings, but are more expensive and more difficult to setup. Direct fired heaters are generally used at construction sites and other open ventilation worksites while being less expensive, easy to move, and more fuel efficient. Call 877-740-RENT (7368) today to reserve your equipment or any of our other services.
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