When You Should Choose an Air to Air Heat Exchanger
An air to air heat exchanger is an excellent enclosure cooling choice that outperforms conventional filtered fan solutions yet is more economical than enclosure air conditioning. The low power consumption coupled with excellent heat removal capabilities make it a good option for cooling remote electrical enclosures, and its low noise levels means that air to air heat exchangers can be placed in quiet areas.
Key Characteristics
The air to air heat exchanger uses a heat pipe to remove heat from an enclosure and discharge it to the ambient air. The heat pipe is a sealed copper tube clad with aluminum fins that aid heat transfer. The tube is partially evacuated and filled with a small amount of refrigerant that boils when exposed to the hot air inside the enclosure. As the refrigerant boils, it absorbs heat, cooling the bottom end of the heat pipe. The hot vapor rises to the top of the heat pipe and condenses, giving up its heat as it is cooled by the cooler ambient air, and flows back to the bottom.
This process requires no outside energy, and the rate of heat transfer simply depends on the temperature difference between the enclosure and the ambient air. Small air circulation fans move the enclosure air and the ambient air across the heat pipe.
Air to air heat exchangers are efficient, economical and simple, and these characteristics make them ideal for many enclosure cooling applications.
When to Use an Air to Air heat Exchanger
Low Power Requirements
Because the only power required for an air to air heat exchanger is for the air circulating fans, these units are ideal for locations where available power is limited. In fact, their low power requirements mean that they can be easily powered by a small solar panel.
Despite this a large air to air heat exchanger operating at a temperature differential of 15 °F can remove 600 watts of heat, which is equivalent to over 2,000 BTU/H.
Moderate Ambient Temperature
Due to the fact that air to air heat exchangers depend on a difference in temperature between the ambient air and the air inside the electrical enclosure, they are used for applications where the ambient temperature is lower than the maximum allowed enclosure temperature.
Remote Locations
Because air to air heat exchangers have no moving parts, they are inherently reliable: they require no maintenance apart from occasional inspection and cleaning of the external air circulation fans and the heat pipe fins. This means they are a good choice for remote and difficult-to-reach locations, and they can be left unattended for long periods of time. The design of the units is such that no filters are required, even in dusty locations.
Noise-Sensitive Areas
Besides the slight hum of the air circulation fans, air to air heat exchangers are silent. They can be used anywhere that excessive noise would be a problem, including in control rooms, office locations, hospitals and residential areas.
Dirty and Dusty Areas
An air to air heat exchanger is a closed loop cooling solution, and the bottom of the heat pipe is completely sealed off from the ambient air. Air to air heat exchangers can be fitted to electrical enclosures designed for use in dirty and dusty areas. Depending upon the intensity of the dust and dirt, air to air heat exchangers can be supplied for use with NEMA Type 12 and NEMA Type 4 enclosures.
Wet and Corrosive Locations
Thermal Edge air to air heat exchangers are available with NEMA Type 4X ratings. These units can be supplied with type 304 or 316 stainless steel housings and are designed to withstand prolonged exposure to water jets and corrosive chemicals, such as those used in the food and beverage industry or in wastewater treatment plants. Additionally, there are models suitable for use in hazardous areas.
In Preference to Filtered Fans
Air to air heat exchangers are a good alternative to the use of filtered fans. They have similar heat-removal capabilities, and the closed loop cooling design means that there are no filters to get clogged and reduce the cooling capacity. Additionally, the interior of the enclosure is kept in pristine condition because no dust or airborne dirt can enter the enclosure.
Air To Air Heat Exchangers: The Rational Alternative
Air to air heat exchangers use hardly any power yet offer a low-cost closed loop cooling solution that is superior to forced ventilation of electrical enclosures. Their simple design and low running costs make them a great solution for use in remote and difficult to reach areas.
To understand more about Thermal Edge air to air heat exchangers, contact your local sales representative.
