Piston Orifice Sizing

[walker]

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?

[Admin]

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.

[walker]

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.

[slo-115]

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

[walker]

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. 

[Admin]

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 

[walker]

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.