Is 500 Microns a Good Vacuum? [Explained]

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Installing a vacuum pump in your HVAC system can be a big hassle. 

What’d be more frustrating is if you’ve installed a vacuum that doesn’t remove moisture from the environment. Thus, it’s highly important to know about micron levels before installing it. 

Now, you might be thinking, is 500 microns a good vacuum? 

The answer is yes, 500 microns is a good vacuum. In fact, 500 microns is a standard vacuum value in many cases. It eliminates 99.99% of the moisture and minimizes the chances of leakages in the system. A vacuum level of 500 microns or below is considered a deep vacuum. Thus it is considered a good vacuum.

However, there’s more to come. Spare us a few minutes, and you will know a lot about the issue.

Why Use 500 Microns

It is considered ideal in many cases. Even some manufacturers accept 500 microns as dry enough. 

For some achieving a micron reading of 500 in their vacuum pump can be a sigh of relief and joy as you can see-

According to vacuum micron charts, a 500-micron vacuum eliminates 99.99% of the moisture. This type of efficiency you won’t find in a 1200 micron vacuum and that’s exactly why 1200 micron isn’t recommended.

500 microns offers better air cleaning and moisture control. Plus, it’s ideal for most home and small commercial applications.

However, a couple of factors and things to consider while making a judgment.

Vacuum level, moisture content, polyester oil & low-temperature application are important factors for maintaining vacuum level.

500 micron vacuum

4 Reasons Why 500 Microns is a Good Vacuum

Several reasons why some consider 500 microns a sweet spot for vacuum systems. The following are the four primary reasons why-

Reason 1: Low Evacuation Time 

While using a vacuum, evacuation time is one of the key factors to consider. A higher evacuation time results in more cost.

A lower evacuation time is cost-effective and indicates a good vacuum system.

500-micron vacuums have an evacuation time of 15-45 minutes which is relatively faster than most systems. 

Reason 2: Good Moisture Control 

One of the key functions of a vacuum is controlling. The core job of a vacuum is to dry out the moisture. 

500 microns or below means 99.99% of the moisture has been removed from the system. And if your system can hold it for 15-30 minutes, there are no leaks.

Such systems are ideal for home and small commercial use. It is efficient in maintaining a standard CFM.

Reason 3: Quick Setup Time 

Setting up an HVAC system can be quite a difficult and tedious task. The setup time is also an essential factor for users.

Setting up a system for less than 500 microns takes much time and requires precision work.

The process is complicated too.

On the other hand, systems greater than 500 microns are not good for moisture control. Even small leaks may happen while setting up the system despite having a low setup time.

Setup Time 

A 500-micron system can be easily set up in 1 or 2 days at best. This is a good time and causes less hassle than other systems.

Reason 4: Holding Time

Perhaps, the most important factor for measuring a vacuum system is the holding time. You can measure it by isolating the vacuum from it’s core tools and allowing the system to stand.

Tips for Getting Accurate Micron For HVAC

You have established your vacuum system, but you require precise micron measurements at this time. A cautious and accurate measurement is needed for any HVAC system. 

Here are some tips on getting a better flow and accurate micron levels;

Tip 1: Choose the Proper Tool: 

A vacuum gauge is needed for measuring the deep vacuum of your system. 

Now, there is a lot of micron measuring gauges in the market. But I’ve tested quite a few and found that some micron gauges are not sensitive enough. 

So I came up with a list of good quality micron gauges for your convenience. Here are some:

  • Digital Manifold Gauge Set – This is perfect for you if you want an accurate reading on a low budget. It’s also well built so durability is in check.
  • YELLOW JACKET – You can set the target vacuum and receive both audio and visual indicators while reaching.
  • CPS VG200 – Has automatic temperature compensation and advanced technology.

An increase in microns that is too slow shows that moisture is still being burned off. An increase that is too fast suggests a leak in the system.

However, readings are impacted by distance from the system and leaking hoses/connections.

Tip 2: Get The Gauge Positioning

Your gauge positioning is important for getting an accurate reading.

Placing it near the vacuum pump will not give you accurate results. Putting it near the pump might even show 20 microns in the meter.

This is because the pump produces a maximum vacuum in the inlet.

Gauge Positioning

Ideally, the vacuum gauge should be located as far back in the system as possible. This will give you the most accurate gauge readings of your system.

Clear off Flow Restrictions:

To vacuum quickly and efficiently, it is recommended to eliminate flow restrictions as much as possible.

Sometimes it might be easier to hook up the pump with a pair of charging hoses. This would prevent any obstruction of airflow. 

But vacuum-rated hoses have a larger diameter. This lets more airflow and makes pulling a vacuum easier. Hence, the pressure is reduced significantly.

Also, it is advised to take the valve cores out of the system’s service ports.

Frequently Asked Questions (FAQs)

Can You still have leaks at 500 microns?

Yes, you can still have leaks at 500 microns but the chances are very low. A good vacuum setup with a powerful pump will prevent leaks at 500 microns. But you need to test the system to confirm this. There are no leaks if your system holds for 15-30 minutes. However, significant fluctuations indicate leaks in the system.

What type of gauge is used to measure a vacuum of 500 microns?

A micron gauge is used to measure a vacuum of 500 microns. A full-range vacuum gauge can measure atmospheric pressure down to 1 micron. However, it is recommended to set the gauge away from the vacuum pump for testing. The gauge gives accurate results up to 2 digits after the decimal.

How many microns is considered a deep vacuum?

Anything on or below 500 microns is considered a deep vacuum. A vacuum of 500 microns eliminates 99.99% moisture and lowers leakage possibility. However, if you cannot hit below 5000 microns, there is a leak in the system. A lower micron value indicates the vacuum is better/deep.


Hopefully, that helped you decide if 500 microns is a good vacuum or not. Do keep in mind that evacuation should not be rushed or hastened.

Finally, don’t forget to keep your piping, vacuum rig, and oils clean. Forming good cleaning habits will keep your HVAC system running for longer periods. 

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