Advanced Evacuation w/ Jim Bergmann

HVAC School - For Techs, By Techs

Bryan Orr

Training, Careers, Airconditioning, Self-improvement, Hvac, Business, Education, Refrigeration, Heating, Ac, Apprenticeship

4.8 • 985 Ratings

🗓️ 16 August 2017

⏱️ 71 minutes

🔗️ Recording | iTunes | RSS

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Summary

Jim Bergmann returns to the HVAC School podcast to cover some advanced topics in evacuation, including rig setups and triple evacuation.

To increase the speed of evacuation, you need two large-diameter vacuum hoses to overcome the limitations of pressure. Core removal is also critical, as Schrader cores are a significant restriction. It's also unwise to use a manifold for evacuation; a manifold will double your hose length, provide a restriction, and serve as a leak point.

The vacuum pump is full of opportunities to expand your advanced evacuation knowledge. The pump oil needs to stay clean, and Jim recommends changing the oil after every use. When it comes to pulling the vacuum, it's worth noting that the vacuum is deeper at the pump than at the system itself. The vacuum at the pump does NOT reflect the vacuum at the system; core tools can isolate the vacuum pump from the system so that you can measure the true vacuum at the system.

When we "break" with nitrogen, we're referring to nitrogen sweeps at different stages of evacuation (especially in the case of a triple evacuation). Triple evacuations are rarely necessary nowadays, but you may need to break with nitrogen from time to time. Nitrogen moves through the system so quickly that breaking with nitrogen often has a minimal impact on the vacuum.

The length of evacuation doesn't really affect dehydration until you get below about 300 microns. Dehydration has more to do with the strength of the vacuum than its length.

Jim and Bryan also discuss:

Locking refrigerant caps
Assembly lubricants
Outgassing odors and gas permeability
Hygroscopic vs. hydrophobic vacuum pump oil
Vacuum pump oil management
Average air conditioning decay rate
Thermistor vacuum gauges
Nitrogen regulators
Metering devices
Gas ballast on vacuum pumps

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Transcript

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0:00.0	This episode of the H.E.A.C. School Podcast is made possible by generous support from all of our sponsors, which include carrier, makers of fine quality, air conditioners, heat pumps, all kinds of different stuff.
0:16.0	You know that.
0:17.0	You know carrier.
0:18.0	Carrier.
0:19.0	Turn to the experts.
0:20.0	Also, thank you to Rector Seal.
0:23.0	Rector Seal sent me recently the new clear-bodied safety switch, Model SS1, I'm sure you've seen the
0:28.5	SS1 switch, but it also comes with a really neat little adapter that you can use to actually blow out
0:34.7	the tee if you use it in line. I'm grabbing it right now. You can actually insert it into the T and use it to,
0:39.7	if you can use it in the primary drain, you can actually use it as a clean out for the primary drain, either like a normal clean out T, or you can use it and actually pressurize it with nitrogen and blow the drain out that way.
0:50.0	It's a pretty cool device and the clear body is actually really nice on it because you can see if there's any water in it no matter what the configuration is.
0:57.0	This episode is also made possible by one of our original sponsors, Testo.
1:02.0	Big thank you, Testo.
1:02.5	Big thank you to Testo for partnering with HVAC School
1:04.9	and thank you to Testo for being willing to work
1:06.6	with the Measure Quick app.
1:07.4	We're really excited to see that.
1:09.0	Relationship gets started.
1:10.5	Testo.
1:11.6	Perfect for testing. Perfect for service. This episode also sponsored by Parker
1:16.5	Zoomlock. Meet Zoomlock, the 10 second flame-free refrigerant fitting from
1:21.0	Parker. Reduce labor costs by 60% with no braising, no flame,
	...

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