Author Topic: Piston Orifice Sizing  (Read 5139 times)

Offline walker

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Piston Orifice Sizing
« on: July 24, 2015, 11:32:40 AM »
Does the SEER rating of an A/C make a difference with what orifice size should be used on a A/C? ie would a 10 or 13 or 14 seer use a different size?

Offline Admin

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Re: Piston Orifice Sizing
« Reply #1 on: July 24, 2015, 12:28:41 PM »
I believe the indoor coil and tonnage of the system would dictate the piston size.

Download the Goodman Piston Chart - Here

If you look at the chart the piston size seems to be the same on some 13 and 14 seer systems, but changes with tonnage or coil type.

Offline walker

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Re: Piston Orifice Sizing
« Reply #2 on: July 24, 2015, 03:29:34 PM »
Ah OK thanks.  Been doing a lot of piston changes from txv on all these Rheem units with the stuck txv issue and have been getting some funny readings in some of them.

Offline slo-115

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Re: Piston Orifice Sizing
« Reply #3 on: July 27, 2015, 12:11:38 PM »
Last year i had a nightmare with adp coils with tx valves, some slammed right shut on start up, other failed several weeks later. Im still afraid of icp coils after constant micro leaks, i see they have gone to a all aluminium "N" coil. Ive always been a believer in the best and most efficient equipment , its sad that a cheap aspen piston coil seems the most reliable. For the extra 1 seer im on the page that the tx valve isnt worth it

Offline walker

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Re: Piston Orifice Sizing
« Reply #4 on: July 27, 2015, 02:10:14 PM »
We've been instructed to remove the txv and change it to a piston.  Replace the filter drier and add in the A/C renew. 

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Re: Piston Orifice Sizing
« Reply #5 on: July 27, 2015, 05:35:31 PM »
I was under the impression this recent TXV problem was caused by a rust inhibitor that Copeland was adding to their compressors.  I believe Rheem uses Copeland compressors.  I found the Lennox C-15-03 TXV Update Bulletin - Here

I wonder how many 15 seer systems that qualified for the OPA rebate will now be turned into 13 or 14 seer systems by switching from a TXV to piston.  That will mess with someone's experiment  :-X

Offline walker

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Re: Piston Orifice Sizing
« Reply #6 on: August 02, 2015, 06:46:22 PM »
well I changed about 15 of them in the last 2 weeks.  customers already received there rebate so they're aren't really to worried about it, they're just happy to have a properly working A/C finally.