Air leaks in HVAC systems in data centers can cause major losses in energy. Studies approximate that 25-30% more energy is wasted just overcoming the ‘leaked cooling’. On a large scale, for example a data center 25-30% amounts to a massive sum. It is possible to detect and plug these leaks. Here’s how:
Typically air leaks in data centers happen at the joints between the wall and the adjoining row of tiles; floor cut outs for cabling, piping, pillars and so on. Additionally drop ceilings, sill plates, water flues, door frames, window frames, electrical boards and plumbing utilities are also major players in the ‘cool’. These locations seem very small in size considering a large HVAC unit but when in tandem they can drain a whole lot of cooling.
There are a number of ways to detect air leaks. Not all the time is it possible to detect air leaks with a wet finger! A different method is adopted to discover different types of air leaks. Here are a few simple tried and tested methods.
An infrared camera is employed to detect air leaks. A solid object will be relatively warmer than a spot that is subjected to continuous air flow. If the infrared camera is set on a high sensitivity, the edge of the solid object will be pictured much cooler than the rest; this is a possible location for an air leak. Cracks are easy to find, a cooler hairline region will be detected to look cooler. It’s that simple with an infrared camera!
In the case of closed rooms a blower test can be employed to detect leaks. All major doors of the room are closed; data center rooms typically do not house windows that can be opened. The blower or a really large fan is placed at the one entrance, oriented outward; this causes all the air inside the room to flow outside. Tiny drafts of air will then be detected at regions of air leakage.
This one’s a little complicated. First a standard list of air pressure with no leakage is made. This would be a benchmark for all the tests. Correlating the ideal data and actual data collected in the room an approximation of the magnitude of air leakage in that room can be detected.
Shut off all HVAC equipment abruptly. Light an incense stick and pass it around common areas of air leakage. An inward draft or a ‘suck out’ of air would mean a leak. This test can be applied in collaboration with the blower test; it would provide continuity in the outflow or inflow that way.
This test is based on a very simple concept and cheap equipment, air drafts and a balloon. In this test, first the HVAC unit is shut off abruptly. A medium sized helium filled balloon is moved along the places where leaks approximated, the tie of the balloon is kept loose to provide adequate motion. Based on the air draft direction the balloon will move. This test is beneficial when there is low ceiling accessibility and there is more need for detection and isolation rather than a fix.
The Air Cookie!
Air leaks can add unnecessary load to an HVAC system. Extra load would mean extra power consumption and heavy electricity bills. Leak detection and a special sweep for air leaks are very essential for smooth HVAC operation. This may be very beneficial if incorporated with a monthly maintenance regime especially in the case of older infrastructure. Plug the leaks, save cooling, save energy and finally save the planet.
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