Q&A – Vacuum Questions Answered

In this episode of the HVAC School podcast, host Bryan dives deep into the topic of vacuum in HVAC and refrigeration systems. He addresses two questions from social media about vacuum, expanding them into a comprehensive discussion of best practices, common issues, and techniques for effective vacuum procedures.

Bryan starts by explaining where to ideally locate a vacuum pump when working on a refrigeration system. He emphasizes the importance of pulling from the largest volume locations possible, often at multi-position service valves on the compressor or wherever accessible ports are available. He notes that systems that have been in operation pose unique challenges due to refrigerant dissolved in the oil, which can significantly increase vacuum time.

The podcast then covers the “one hose method” for pulling vacuum, detailing the process of using a single large hose connected to the suction side with the core removed, while placing the micron gauge on the liquid side. Bryan explains how this method can be highly effective for new systems but may take longer for systems that have been in operation. He also discusses the importance of valve quality.

Key topics covered in the podcast include:

Ideal vacuum pump location in refrigeration systems
The “one hose method” for pulling vacuum
Challenges of vacuuming systems that have been in operation
Using heat and nitrogen to improve vacuum efficiency
Importance of quality valves and tools in vacuum procedures
Proper maintenance of vacuum pumps and micron gauges
Dealing with refrigerant dissolved in oil during vacuum
The science behind evaporation at the oil-vapor interface
Tips for speeding up vacuum in difficult conditions
Recommended resources for further learning about vacuum techniques

Get your copy of Review of Vacuum for Service Engineers at TruTech Tools HERE.

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.

Subscribe to our podcast on your iPhone or Android.

Subscribe to our YouTube channel.

Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

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#deep vacuum #evacuation #hvac #micron #micron gauge #nitrogen #vacuum

Author:

Bryan Orr

Company: HVAC School

Position: Founder

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In this short Q&A podcast episode, Bryan answers Edward’s question about how to deal with customers who ask, “Why didn’t you notice it last time?”

There isn’t an easy answer to that question. The truth is that air conditioning and home health and comfort issues are complicated, and it’s entirely possible that an issue simply went unnoticed (or the symptoms simply weren’t apparent yet). The HVAC industry doesn’t have a standard slate of tests that can give a comprehensive view of everything that’s wrong with a system all at once. It’s similar to how a doctor can offer a second opinion that differs from the first doctor you saw.

You have to determine whether the customer wants to place blame or solve the problem when they ask, “Why didn’t you notice it last time?” Sometimes, we need to dig deeper to find the root of the problem. We can offer advanced diagnostics and be honest about what that will entail (including pricing), though it’s natural for customers to be apprehensive about being sold options. However, we don’t want to avoid pursuing solutions either.

There are ways to talk about previous sloppy or incomplete work without placing blame on another technician. The immediate problem is what requires attention, not the last person who worked on the system. Ask the customer to state their goals and the results they want to see, and you can forge a path ahead.

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.