Overview
An air heater passes a hot medium through finned tubes and across the tubes forces the air that has to be heated. The first decision is always the heat source, because it sets the pressure rating, the temperature ceiling and the control behaviour of the whole unit. Saturated steam releases latent heat and heats up quickly but pressurises the tubes; hot water is gentle and needs no pressure rating; thermal oil reaches high temperature at low pressure and can be controlled closely.
Features
- Three heat sources: saturated steam, hot water and thermal oil
- High-pressure construction available for steam duties
- Tube materials: copper, stainless steel and carbon steel
- Fin spacing matched to whether the air stream carries dust
- Connection positions and casing shaped to your duct
- Series supply proven on washing and drying equipment lines
Materials and specifications
| Heat source | Saturated steam, superheated steam, hot water, thermal oil |
| Tube material | Copper, stainless steel, carbon steel |
| Fin material | Copper, aluminium, stainless steel |
| Fin type | Wound, sleeve-on, embedded, high-frequency welded, brazed |
| Heated medium | Air, process gas |
| Construction | Finned tube bundle with casing and inlet / outlet connections |
Typical applications
| Application | Description |
|---|---|
| Washing and drying equipment | Steam coils built into tunnel washers and drying lines, sized to the duct. |
| Food and agricultural drying | Continuous dryers needing a stable supply of hot air. |
| Textile finishing | Heating air for stenter and drying processes. |
| Space heating | Hot water coils for workshops and make-up air units. |
| Chemical and pharmaceutical | Process air heating as part of a drying or reaction stage. |
FAQ
Which heat source should I use?
Use whatever is already available on site. If you have a steam system, steam is usually best because the latent heat transfer keeps the coil compact. If you only have a hot water boiler, a hot water coil is simpler but the achievable air temperature is lower. Where high temperature is needed without high pressure, thermal oil is the answer.
Can you supply high-pressure steam air heaters?
Yes. Copper tube bodies have a lower pressure rating than steel, so we use thick-wall tubes with specific expansion and brazing processes for high-pressure steam duties. We have supplied high-pressure copper tube, copper fin steam heaters to the Russian market for a number of years.
How do I specify an air heater?
Give us the air flow rate, inlet and outlet air temperature, the allowable air-side pressure drop, the heat source parameters and the installation envelope. We then calculate the surface area and propose the tube and fin arrangement.
Does dust in the air stream matter?
It does. Dusty air streams need a wider fin spacing so the passages do not clog, and the coil should be accessible for cleaning. Clean air streams can use a denser fin pack, which makes the unit more compact.