Simple AC tips to help keep your cool this summer

[Bugeater]

Originally Posted by Chief Roundup

It is always best to look. But if you can get model and serial you can also call your distrubitor and tech support of the manufacture and they can tell you. If you are doing maintenance in and or on a specific building it won't take long to find out.
This much I can tell you if it is 410 it will have an expansion valve or an R-22 that is a 13 SEER or higher it will have one as well. Most of the older units don't have them but if someone has changed a condensor and left the old coil then they should of added a TXV.
Here is something that I had to learn the hard way. That a load of people don't know. If you are working on an American Standard or a Trane and you have to change a compressor out. There are 2 line driers that look like mufflers on the side of the condensor where the lines come out of the coil and go back to the compressor.
I didnt know about those so I put a new line drier at the evaperator coil and it basicly made a restriction.
Are you working on anything other than residential split systems yet?

That's interesting that you say that, I had my condenser changed out a couple years ago and I don't believe they changed the evap, and it doesn't have a TXV. I know the pistons are model-specific as well, and I have no idea if they put the proper one in either. That's another reason I went to school for this, it drove me nuts not knowing how the heck any of this stuff worked, and you have no idea who you can trust in the business.

I haven't taken any classes on commercial systems yet, and I have PTACs at one of my properties and all I've learned from them is that they are a complete pain in the ass.

[Chief Roundup]

Originally Posted by Bugeater

That's interesting that you say that, I had my condenser changed out a couple years ago and I don't believe they changed the evap, and it doesn't have a TXV. I know the pistons are model-specific as well, and I have no idea if they put the proper one in either. That's another reason I went to school for this, it drove me nuts not knowing how the heck any of this stuff worked, and you have no idea who you can trust in the business.

I haven't taken any classes on commercial systems yet, and I have PTACs at one of my properties and all I've learned from them is that they are a complete pain in the ass.

Don't trust anyone else in this business! There are to many people that think they know what they are doing simply because they have been doing it for 20 years.
If you know the series of operations and the flow of refrigerant you should be alright. Things just get bigger. Meaning 2 speed equipment, bigger tonage attained by multiple compressors and so on. Be sure to learn your 3 phase power stuff for the commercial work.
Now you will find some equipment that uses amonia as its refrigerant in larger buildings. Be very careful with those units. Amonia is a lot more explosive than other refrigerants.
PTACS do suck but they are basicly glorified heat pump window units. Cheaply made and not meant to be repaired much.

[Bugeater]

Originally Posted by Chief Roundup

Don't trust anyone else in this business! There are to many people that think they know what they are doing simply because they have been doing it for 20 years.
If you know the series of operations and the flow of refrigerant you should be alright. Things just get bigger. Meaning 2 speed equipment, bigger tonage attained by multiple compressors and so on. Be sure to learn your 3 phase power stuff for the commercial work.
Now you will find some equipment that uses amonia as its refrigerant in larger buildings. Be very careful with those units. Amonia is a lot more explosive than other refrigerants.
PTACS do suck but they are basicly glorified heat pump window units. Cheaply made and not meant to be repaired much.

Heh, we have a commercial rooftop unit that cools the hallways in one apartment building, and I noticed the two huge compressors in it. That thing intimidates me...lol. Haven't had any trouble with it other than it inexplicably froze up after we had a power outage, but I just shut it down for a day to let it thaw and it's been fine ever since then.

[Chief Roundup]

Originally Posted by Bugeater

Heh, we have a commercial rooftop unit that cools the hallways in one apartment building, and I noticed the two huge compressors in it. That thing intimidates me...lol. Haven't had any trouble with it other than it inexplicably froze up after we had a power outage, but I just shut it down for a day to let it thaw and it's been fine ever since then.

Those 2 compressors do not pump refrigerant through the same lines. They have seperate refrigerant lines that run through the same coils. I was taught to think of them as 2 systems working in series to make it a 15 ton or whatever tonage the unit is. So if you have a problem with the charge you will have to check the charge the same number of places as you have compressors in a unit. I have worked on some that you have to crawl up in the rooftops to service all 6 compressors.