Short #61 - EPR vs. CDS Valves

HVAC School - For Techs, By Techs

Bryan Orr

Education, Business, Self-improvement, Careers

4.9 • 1K Ratings

🗓️ 2 July 2019

⏱️ 11 minutes

🔗️ Recording | iTunes | RSS

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Summary

Bryan talks about EPR and CDS valves. We consider both to be evaporator pressure regulators, but they really function quite differently. CDS are Sporlan components that appear to be quite similar to evaporator pressure regulators (EPRs).

EPRs go in the suction line and control the evaporator pressure. The pressure and temperature relate to each other, so the goal is to keep the evaporator from freezing by controlling the pressure. However, EPRs rely on a pressure drop across them to be able to do their job, so compression ratios will increase, impacting power consumption. We primarily see EPR valves in supermarket refrigeration on rack systems.

Electronic EPRS (EEPRS) include the Sporlan CDS valve. However, EEPRs do NOT actually measure the pressure in the evaporator coil in the same way that a standard EPR does. (However, they are evaporator flow regulators.) The pressure of an EPR is fixed via mechanical parts, but the CDS valve relies on a signal from the controller to set targets depending on the air temperature. The CDS valve can modulate via a stepper motor to maintain a certain target.

Sporlan CDS valves have a lot of benefits. For example, you can reset or adjust the CDS valve without manually adjusting it; you can easily adjust the controls. CDS valves also don't require a pressure drop because they do not rely on a mechanical process to work. If you encounter modulation issues with your CDS valves, you can power cycle them. Sporlan SORIT valves have a separate solenoid, but the stepper motor allows the CDS valves to close fully.

Overall, CDS setups can save a lot of energy and are quite easy to use because of their integration with controls. Unfortunately, they are prone to failure from power surges.

Learn more about Refrigeration Technologies HERE.

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Transcript

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0:00.0	Hey this is the HVAC school podcast. Today we're going to talk about something that you may not even have any idea what I'm talking about which is the difference between EPR and CDS valves which I think even if you don't know what they are by the end of this,
0:15.8	hopefully you'll know a little bit more and you might know a little bit more about a few things,
0:19.4	hopefully. But anyway, first we got to thank our sponsors.
0:22.0	First sponsor to thank is Field Peace and Field Peace.com.
0:24.8	Field Piece makes the MR-45 recovery machine, Mr. 45, great recovery machine. We've got a bunch of
0:31.1	them out there in service at Kailos as well as the VP
0:35.1	85 vacuum pump. Both of them have a similar form factor. It's kind of like
0:39.3	rectangular. They fit really nice in the van. They both have DC motors and they both do a great job and we love them and they both work on
0:47.3	Low voltage so if you have a case where maybe you're on a roof or something and maybe you got a long cord
1:00.0	They're still generally gonna do a good job even if you get a little bit of voltage drop because of the DC motors. You can find them and much more at truetech tools. Use the offer code get schooled for a great discount at check out and also take a look at fieldpiece.com
1:05.4	I also want to thank our other sponsors refrigeration technologies
1:09.3	Navac at navac global.com and speed clean at speed clean clean
1:13.7	clean dot com find the duckless cleaning guide by us and speed clean we did it
1:17.9	together comprehensive guide by going to hvacr School.com
1:22.8	forward slash Minnes Split, HVacr School.
1:25.8	dot com forward slash Minnes Split.
1:28.4	All right, so let's talk about EPR versus CDS.
1:32.2	And CDS is actually a Sporlin model so CDS I don't really know what it stands for
1:36.6	something but it's just a particular Sporlin model that's sort of the ubiquitous most common type of valve and a lot of people will call it an EPR
1:46.6	electronic EPR but that's maybe a little bit of a misnomer and we're going to get into that
1:50.5	so first off I have to thank Jeremy Smith as always Jeremy is sort of my
1:55.2	refrigeration guru my brother Nathan also does a lot more refrigeration now but he's the
	...

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