Positive Pressure vs. Negative Pressure
Positive pressure heaters have a blower with the burner and it pushes the air into the tube to the exhaust end. The negative pressure heater has the blower on the exhaust end and pulls the air into the heater at the burner end. In many applications you can use either type of heater just fine. The positive pressure heater should be used when you have a “dirty” atmosphere, such as in a car wash, wood shop, pool, or spray paint is used. The reason is the burner and blower are enclosed in a single housing, so it can be isolated from the ambient air. You run vent pipe from outside to the box and then exhaust through vent pipe to the outside. It is not explosion proof. With the negative pressure type heater, the blower is exposed to the air. Dust, dirt, and moisture can accumulate on the motor and blower wheel and cause problems.
Where do they heat?
They are designed to heat large commercial spaces such as: warehouses, auto dealerships, aircraft hangars, farm buildings, garages, shops and open air business’s like car washes. Tube heaters are long straight or U shaped tubes that carry heat over a long distance, they come in 15, 20, 30, 40 and 50 foot lengths. They come in both propane and gas radiant tube heater options.
What is Infrared heat?
Infrared heat works from the bottom up, warming people, the floor and machinery first. Heat is retained in the lower working areas of the building making it more efficient and more uniform heating. Benefits include: fuels savings of between 30% to 50% in some cases. The efficiency of a heater radiant tube distributes heat in a wide area allowing objects in a fab shop, plant or pole barn to absorb more heat.
How to Determine Heater Sizing?
One of the first steps in sizing the right heater is to take a few measurements in your shop. Take a measurement of the length, width and height of your space. From there you can calculate the square footage by multiplying length times the width.
For example: a 50' x 50' space is 2500 square feet. Next pay attention to the height of the ceiling. Our Sunstar radiant heaters have recommended mounting height requirements when suspended in a building. If you are too close it might make it too uncomfortable for the people underneath the heater or you can possibly damage the paint or material of your vehicle or machinery. It's a good idea to view the min clearances of the heater under the manufacturers specifications.
Where are they used?
Another important aspect is the location or the state you live in. Each state has different outside temperatures during the colder winter months. This will give you a baseline of worst case or best case scenario if the heaters were off and your space was as cold as the outside temperature.
How to set the temperature
What is your desired temperature? Do you want to get to a comfortable 60-70 degree's or do you have a different application? Take note of that temperature setting it will play a key role in your configuration.
Structure composition
What type of material is your building, a metal or concrete structure? Depending on your insulation, this will allow you to understand the heat loss estimation a little bit better. Concrete structures like a shop tend to have less heat loss than metal structures. Does your space have garage doors that open and close during the day, windows or other openings? All these variables should be taken into consideration when sizing the correct sunstar heater. If heating a residential property a garage tube heater is typically smaller then standard heaters and come in around 10 feet and can be suspended at a lower height and are lower intensity.
Helpful Hints
When specking out your heater always try to stay above the required BTU otherwise if you're under that desired BTU your units may stay on longer using more power to run them and the fuel savings may go down. Find out the current and possible future cost of propane or natural gas as these fuel costs can change quickly.
We also recommend when you leave your shop, or warehouse do not turn off the heaters but set them to a lower temp say 50 degree's so the space has a baseline of heat before you come in the next morning. This way the heater or heaters won't have to work as hard to heat the space.
Do you need a Straight Tube or U Tube?
There are 2 different styles to choose from, you have the option of a low intensity straight tube system which is Sunstars SIS unit or u-tube heater which has a u shape. The SIS systems come in 15' lengths all the way up to 50' depending on the BTU for that unit. The SIU units come in similar lengths but have a smaller foot print as the tube has a 180 degree bend at the end. Other sunstar heaters include SIR, SPS and SPU.
SIU systems tend to heat more uniform overall then your standard straight tube. This is why the SIU or U tube heaters work better in a spot heating environment where you're trying to get heat for example to a work area or specific place in your space.
