FAQ

Frequently Asked Questions

Find answers to the questions you may have about getting a heat exhancher for your business.

What is the maximum operating pressure for air-to-air heat exchangers?

Plate units – Operating pressure 1 Psig, differential pressure (pressure difference between the two streams) 1 Psig.
Tubular units – Up to 5 Psig

What is the maximum operating temperature for air-to-air heat exchangers?

Plate units – 1200°F (uninsulated), 1500°F (insulated)
Tubular units – 1600°F (fresh air outlet temperature limited to 800°F)

I have a dirty air stream. What heat exchanger should I use?

A tubular heat exchanger with large ID tubes. PRE-heat recommends that the dirty flow goes through the tubes in a vertical down direction.

I have an air stream that includes corrosive elements. What type of heat exchanger should I use?

With robust construction, thicker gauge materials and the availability of higher-grade alloys, a tubular heat exchanger can provide the best corrosion resistance.

I have limited space. What type of heat exchanger should I use?

A plate type heat exchanger is the most effective type of air-to-air heat exchanger and will take up the least amount of space.

I do not have space for a tubular heat exchanger, but I’m afraid of fouling. Can I still use a plate unit?

For moderate dust loads, yes. To reduce the likelihood of fouling, PRE-heat will increase the plate spacing (>1/2”) and use an inline dimple pattern. To help with cleaning, the heat exchanger can be supplied with removable panels which provide access to the heat exchange surfaces for cleaning and inspection. Finally, PRE-heat recommends that the dirty flow goes through the straight through pass (I-pass) in a vertical down direction.

What is the difference between effectiveness and efficiency?

Thermal efficiency is based on the flue temperature, the type of fuel used, ambient conditions and any excess air.
Effectiveness takes into consideration heat capacitance differences between streams, mass flow differences, moisture content and total heat, making effectiveness a better measure of the performance.