Absolutely not. The refrigerant is in a closed loop. If you are topping it off yearly, you have a leak. If a tech told you that, never let him or his company touch your HVAC.

Just for info, i recently checked my HP DF system 9+ yr old, and charge is right on the money, never ever added any refrigerant.

IMO

I had mine refilled in 2011. Now, the serviceman says he added 2.59lb and that it will run more efficiently. There is really no way for me to check it, since the access to the roof of the building is closed.

You got what in the industry is called a gas n go. Problem is still there and will bite you again in the pocket. Unless you don't have a leak and he charged you for a service that never took place.

IMO

Evelina74

tigerdunes is correct, the refrigerant system is (supposed to be) a closed loop. It does not need additional refrigerant unless it's leaking.

It's not just the access to the roof that prevents you from verifying that he added anything, you would need a lot of equipment and know-how and to have checked things before he did any work.

But the bottom line is that if a system is low on refrigerant then it's leaking (assuming it was charged properly to start). It's not an acceptable practice just to add some refrigerant -- you have to find and repair the leak.

But the other issue is that it's not easy to determine the proper charge on an existing system. Many repair techs just "wing it" and guess because they were never trained to do it correctly. On a system with a TXV (many systems now) the only correct way to determine the correct charge is using the sub-cooling method.

Ask your service tech:

1.) how did he determine that it was low?
2.) where was it leaking and how did he fix it?

If he answers anything but using the sub-cooling (or superheat if you don't have TXV) method for question 1 then he should not be working on your system at all.

If he didn't find a leak and didn't look for a leak then he shouldn't be working on your system at all.

I think the answer to both questions in this case will turn out to be, "he shouldn't be working on your system at all".

The link below explains the sub-cool method of determining the proper charge on a unit. I don't expect anyone who's not an HVAC person to understand it completely, but I post it so people get that it's more involved than "feeling the pipe and seeing if it's cold" or "I looked at my gauges".

Here is a link that might be useful: Sub-cool method of charging AC unit

This post was edited by jakethewonderdog on Mon, May 12, 14 at 14:24

His explanation is that the unit is a cheaper builders model. Thank you Tigerdunes and Jakethewonderdog. You have been a big help.