Why Do You Need a Proper Vacuum Pump for Your HVAC System?

HVAC system is the abbreviation for heating, ventilation, and air conditioning. It is the technology used in households, and in vehicles to achieve temperature control. It is used for acceptable and inhalable air quality; to regulate the temperature per the outside climate and purify the inside air to remove unwanted moisture. HVAC is used almost everywhere these days starting from apartment flats, duplex houses, hospitals, office buildings, a startup to giant industries, police stations, airports, and community halls to vehicles like cars, buses, trains, airplanes, ships, cruise, submarines, etc.

Vacuum Pump

A vacuum pump’s mechanism is to create a vacuum in the required vessel by removing any air or gas particles present. It is generally used for industrial purposes such as in electronic manufacturing units to produce CRT tubes, electric bulbs, etc.

In a HVAC system, V stands for ventilation which is the process of interchanging air from indoor and outdoor and hence regulating the temperature and purifying the air. It involves two processes: it introduces outside air inside and circulates the interior air to prevent saturation of the air. It is also responsible for removing not so pleasant smells and excessive moisture. It can be done both naturally and mechanically.

The Need of a Vacuum Pump in a HVAC System

Since the HVAC system ventilates air from inside to outside and vice versa, it is possible to have some of the gas particles trapped inside. The system needs servicing from time to time to ensure the flawless function of the heating system and air conditioners. A vacuum pump is used to remove unwanted air and water vapors from the air conditioning system while it is under service and to restore the vacuum. CFM (Cubic Feet per Minute) is the unit on which vacuum pumps are evaluated; bigger pumps don’t ensure better quality or faster to use. CFM defines the speed at which it can evacuate the system; it can be at times even more than the size of the pump itself.

How the Vacuum Pump Works for HVAC System

The first step is to take out the refrigerant from the system and save it for later usage. Then, proceed with a thorough check-up for any defects, such as leakage. At times, water starts to flow back from air conditioners; this is an indication of leakage in the system which requires immediate attention. When the leakage is detected during service, it should be fixed first, or the total vacuum condition cannot be attained. Also, refrigerant will leak leading to its wastage. After the reassurance of no more defects, we can now evacuate the air and moisture using a vacuum pump. A full integration testing is done before it is handed over to the customer to ensure flawless delivery.

Evacuation Process

In an ideal system, only the refrigerant and oil should be circulating in the system. However, after many years of operating the device without servicing it may accumulate air and moisture. The air from the atmosphere includes oxygen, nitrogen, and moisture. These particles can cause unwanted results such as a rise in head pressure causing higher compression ratios. This will overall result in the decreased efficiency of the system. Also, acids produced in refrigerant can cause chemical reactions and acids might also corrode the walls of metal over time.

Tips to Keep in Mind While Selecting an Air Conditioning Vacuum Pump:

  • Sight Glass Oil

To see the level of oil before operating, it is needed to have sight glass oil.

  • Anti-Suck Back Feature

Both the refrigerant and the pump have oils but they are quite different from one another, hence anti-suck back feature is needed before servicing so that oil from the pump does not flow into the refrigerant system in case there is a power outage. The oil in the refrigerant is different from the ones in the pump.

  • CFM Rating

The higher the CFM the faster the evacuation process is.

  • One-Stage or Two-Stage Design

As the name suggests, one-stage and two-stage designs have one and two rotors and vanes respectively. The dual-stage vacuum exerts greater pressure and hence, the two-stage design pump is more efficient and can produce a deeper vacuum than the former one. Single-stage vacuum pumps are less expensive and work well with a rough vacuum level. Depending on the requirement, single-stage or dual-stage vacuum pumps should be used.

  • The Lowest Vacuum Level That the Pump Can Achieve

The vacuum level is defined as the difference between evacuated volume and surrounding pressure. The lower the vacuum level, the lesser the difference with the surroundings. Hence the lowest possible pressure is zero.

  • Intake Fittings

Proper intake fittings are important with any and every gauge. Hence, it is very important to ensure proper fittings of the vacuum pump before starting the whole troubleshooting service. Otherwise, there remains a chance of accidents or wastage of oil and refrigerant which will ultimately lead to an inefficient vacuum created in the resulting vessel.

  • Weight

Lightweight vacuum pumps are easy to handle, hence preferred.


After concluding all the facts specified here, we can conclude that a proper vacuum pump is very much required for any HVAC system. Starting from the troubleshooting procedure to create the vacuum perfectly and lastly testing the end product to ensure it is free of any defect. Hence, we should analyze the HVAC system and then the required vacuum pumps accordingly for a working system.

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