How To Vacuum AC Without A Pump?

Replacing the refrigerant gas in your domestic mini-split-level air conditioning unit or your car or fridge must have a root cause. It is either a new installation, replacing a major component such as the compressor, or repairing leaks in the closed-loop gas system. The refrigerant gas is nasty to the environment and potential to the unskilled DIY enthusiast, trying to step over a dollar to pick up a penny.

There are no shortcuts to refilling the air conditioner system with Freon gas. A vacuum pump must draw out all the air and moisture in the system, and then a leak check is done.  Moisture will destroy the compressor seals and corrode the system leading to premature failure.

Air conditioner manufacturers and installation experts stress the importance of drawing a strong vacuum on the system before filling it with Freon gas. Properly installed and commissioned, the domestic split level air conditioner should never need to be recharged with gas during its 12 to 15-year service life.

Let’s look at why this issue of charging an air conditioner system without using a vacuum pump is being asked.

Why Should A Vacuum Pump Be Used To Evacuate The AC System?

Doing a job right the first time is a motto that is well worn and yet still not accepted by all. In researching this report, I did some extensive reading on the internet. I watched a few YouTube videos of people claiming to be able to recharge their AC without the need for a vacuum pump.

The evidence presented by these claimants was not compelling, to say the least. Their reason for attempting the operation without a vacuum pump was that they did not have a vacuum pump. Hopefully, they will avoid sky diving!

Of the two YouTube videos, it was clear that the AC system that was being refilled was not new and looked to be well used. On the internet, the instructions are very similar. All started by requiring the installation of high-pressure and low-pressure valves, an installation best done by experts in air conditioner installation.

The sketchy procedure then describes how to re-gas the system while ignoring that there will still be some traces of moisture in the system. The process also does not allow the re-gassing technician (let’s be kind) to check for any system leaks.

The method may work for a while but will result in premature AC system failure. Just like the parachute manufacturer will insist that it is critical to deploy the chute when jumping out of a plane if you want to survive the landing, the manufacturers of AC systems all insist that a vacuum pump is used to thoroughly draw all moisture out of their system.

Only the refrigerant gas/liquid should be inside the closed-loop system for an air conditioner to function optimally. The compressed refrigerant liquid expands to become a gas when it flows into the tubes inside the AC lines. The gas will absorb the heat and expand as it exits the cooling zone and enters the condenser, where the gas will lose the heat before the compressor once again forces the gas into a cold liquid.

Air conditioners fail when the closed-loop system develops a leak due to the successive cooling and heating cycles that can cause metal fatigue. Soft aluminum or copper is used in AC loops as these metals are good heat conductors and are good at coping with the mental fatigue of heating and cooling.

Critical joints in the AC system will contain high-precision rubber seals to ensure that the system is leak-free. These rubber seals can become brittle and crack as the solvent oils in the rubber compound escape.

Leaks in the system will allow the Freon gas to escape and draw moisture into the system. The moisture will form an acid which is deadly to the metal tubes and rubber joints. Complete AC failure is imminent.

Do you have Intex pool? If yes, know “How To Vacuum Intex Pool Without Skimmer?

What About Slow Leaks On Car AC Systems?

Small leaks in your car or truck AC system may cause the system to work below par during the hottest summer months but be good enough during the rest of the year. A complete system repair may cost you a lot of money for keeping cool during the hottest two months of the year.

Quick-fill kits are available from automotive repair shops that allow a DIY recharge to be done quickly and easily, just before the hot months start. The AC Pro Car Air Conditioner Synthetic R134A Refrigerant and AC Recharge Kit with Hose and Gauge are available from Amazon at $50 for a 20oz bottle.

This annual procedure can save you from making an expensive repair on a very slow leak but is just delaying the inevitable. A complete AC recharge kit includes the vacuum pump, pressure gauges, pipes, connectors, and oil costs a mere $130 on Amazon.

The vacuum pump and recharge kit will be required to properly recharge the AC system after the repairs have been done.

Slow Leaks On Home AC Systems – Quick Fixes?

Searching for leaks on a split-level domestic AC unit is not a job that a novice should attempt. If you value your time and sanity, getting an AC expert in to troubleshoot a unit that is not performing to expectation is well worth the money.

An expert AC technician can quickly detect the leaks using UV dye and a Halogen Refrigerant Leak Detector. The remedy may be as simple as injecting some leak sealant in the lines and replenishing the refrigerant gas. Or it may entail a more extensive repair above the pay-grade of the DIY homeowner.

Domestic AC systems are designed to have a useful service life of 12 to 15 years. Professionally installed and serviced units will provide you with many seasons of comfort. The refrigerant gasses are very bad for the environment, making AC systems’ service and repair a task for the qualified technician.


Charging an air conditioner with refrigerant gas requires the thorough evacuation of all gas in the system to remove all traces of moisture and air. The system must hold the vacuum for at least 30 minutes to check for any leaks. 

The vacuum pump must be used to draw the refrigerant gas into the system slowly and steadily over 45 minutes. The amount of gas must be measured to assure that the system is not over or under filled.

Do not follow the false claims of DIY air conditioner experts on the internet. You can avoid the discomfort and cost of a poorly functioning AC system by paying an expert or investing in the correct tools to do the job right the first time yourself. 


This is the site where I share all of the information about home security. I have been working in this industry from last 10 years and therefore, sharing all my experiences and learnings.

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