VRF in Real Life w/ John Oaks

HVAC School - For Techs, By Techs

Bryan Orr

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

4.8 • 985 Ratings

🗓️ 17 January 2019

⏱️ 52 minutes

🔗️ Recording | iTunes | RSS

🧾️ Download transcript

Summary

In today's podcast, I talk to John Oaks about his experience as a VRF tech in the field, including branch boxes and two-pipe vs. three-pipe technology. John primarily works on the troubleshooting and service side rather than the installation and programming side of the field.

Variable refrigerant flow (VRF) systems, also called VRV systems when manufactured by Daikin, are commercial HVAC systems. VRF systems work best in commercial buildings with some degree of fragmentation, like offices and medical facilities. These systems are similar to multi-zone ductless systems, but they operate on a much larger scale. VRF systems have a branch box, which acts to direct traffic between the various zones of a building and parts of the system; the branch box allows the unit to heat and cool simultaneously.

A 24v signal drives most of the controls. These controls are "daisy-chained," as VRF systems are very interconnected, and a defrost signal can have up to about 50 destinations to various components. The entire VRF installation process requires careful attention to detail, not just on the programming side.

When it comes to common issues with VRF systems, the refrigerant charge is one of the most critical problem areas. These systems mask issues with the charge, so it is difficult to find out if a system is undercharged or overcharged. In addition, you can't weigh out the charge in the same way that you would in a residential system.

John and Bryan also discuss:

Metering device placement
Industry improvements and upgrades
Inverter boards
Line set length and charge issues
Flares, brazing, and ZoomLock
Condensate removal and drainage strategies
Diversity of zones and efficiency
Two-pipe vs. three-pipe configurations
Cooling mode, heating mode, and mixed conditions

Learn more about Refrigeration Technologies HERE.

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Transcript

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0:00.0	and This episode of the HVAC School podcast is made possible, truly made possible by our
0:20.4	sponsors.
0:21.4	Carrier, carrier.com, we are carrier dealers, I'm proud to be a carrier dealer and there's a lot to like about
0:26.3	carrier you can find out more by going to carrier.com or talk to your local carrier
0:30.4	distributor ours is carrier enterprise.
0:32.8	I also want to thank Field Piece for coming on board and supporting the
0:35.6	podcast.
0:36.6	I'm very thankful for their integration with Measure Quick.
0:39.3	A very wise decision that they made to work with Measure Quick and it really is a perfect marriage
0:43.8	between their probes and the Measure Quick app. If you haven't tried them together, I would
0:48.3	suggest looking at their JL3 probes, but also their MR45 recovery machine and VP
0:53.8	85 vacuum pumps. We use a ton of them at Kailos. They really are
0:57.8	industry leading products, very, very nice products. You're going to
1:00.6	want to check those out. Find out more by going to
1:02.8	Fieldpiece.com and then Navac, Navac Global.com, Navac makes lots of really
1:08.0	high quality products, recovery machines, vacuum pumps. They're coming out with a
1:11.6	new line of hoses and some other products, but they also make a compact
1:15.4	swedge tool that I actually am coming around to. When I first saw it, I didn't quite know
1:19.9	how to use it, and I didn't get the results that I was hoping for but once I learned
1:23.4	how to use it it really is a nice swedge tool to keep in the bag. My oldest son
1:27.1	just got his first veto bag and I'm gonna give him one of those hand
1:30.9	swedges to put in his veto bag. Nice tool.
	...

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