Temperature tales - Vacuum pumps for the HVAC and refrigeration industry

Control.

That is the core of the HVAC and refrigeration industry.

HVAC, which stands for Heating, Ventilation and Air conditioning, focuses on controlling indoor temperature, humidity and air quality. Refrigeration, on the other hand, focuses on controlling and lowering the heat from a space to lower and maintain its temperature below that of the surroundings. 

Across industries and everyday life, HVAC and refrigeration systems work around the clock to ensure perfect temperature control at different levels - from large scale ventilation systems for corporate buildings to your simple home refrigerator. 

The efficiency and performance of these temperature control systems rely heavily on one critical process -proper system evacuation. System evacuation is just the simple process of removing air, moisture, and non- condensable gases from a refrigeration or air-conditioning system for it to function properly. 

And the tool needed for this process?... You guessed it, the humble vacuum pump.

Well, refrigeration and air-conditioning systems must operate in a clean, moisture-free environment. Even small amounts of air, moisture, or noncondensable gases can cause:

• Reduced cooling efficiency
• Higher power consumption
• Formation of acids inside the compressor
• System corrosion
• Premature component failure

That’s where vacuum technology comes to the rescue. For HVAC systems, vacuum pumps can evacuate and remove these contaminants before the refrigerant (a chemical compound used to absorb and release heat, allowing cooling or heating to take place) is released. They essentially clean the inside of the system so that the refrigerant can circulate efficiently with strange contaminants floating about inside. 

Vacuum pumps create negative pressure by removing gas molecules from a closed system. This reduction in pressure forces moisture to boil off at low temperatures, allowing it to be extracted along with air and other unwanted gases.

The process generally happens in 4 main stages:

Initial pump down - The vacuum pump begins by removing large volumes of air from the system.

Deep vacuum pull - Once most of the air is gone, the pump pulls the system down to a much lower pressure level (below 500 microns). At these deeper vacuum levels, remaining gases/air pockets begin to release from the internal surface

Moisture removal (dehydration) - By reducing the pressure inside the system, the vacuum pump causes any remaining moisture to boil off, even at room temperature.

Vacuum holding test - After reaching the target vacuum, the pump is isolated or turned off to see if the pressure holds steady. If the vacuum rises (loses depth), that indicates a leak. Testing for leaks is extremely essential during HVAC installation, AC servicing, and refrigeration maintenance time.

The kind of vacuum pump needed for a HVAC and refrigeration system really depends on the size of the system, and its cooling or heating needs. Different jobs call for different pump technologies.

Oil-sealed rotary vane vacuum pumps are an industry standard technology. They are preferred for everything from residential and light commercial HVAC installations, routine HVAC servicing, and small refrigeration units etc. Our Atlas Copco’s GVD series is an ideal choice for this. They are known for their high ultimate vacuum, rapid pumping speeds, quiet operation and ability to handle water vapour.

For laboratory-grade refrigeration systems and specialized HVAC applications, dry rotary vane vacuum pumps are more suitable. Unlike oil-sealed models, these operate without lubricating oil, reducing risk of oil backflow and ensuring clean functioning. For this, you can explore our Atlas Copco DVS range of dry rotary vane pumps - they offer a clean operation, free of emissions and no contamination to the process, in simple and compact design.