Roof Air units - Recharging?

[WEC4104]

We must be getting into the season, 'cause there are a lot of air conditioning questions flying on the board recently.   It has been unseasonally cool and rainy here lately, but I have my own question to toss out.

My 4104 only has a single roof air unit (Coleman 13.5 BTU) and it really does a pretty decent job.  Mind you I don't spend a lot of time in Phoenix, but it did make Georgia and Alabama tolerable last July.

This unit was installed my the previous owner, and it has to be at least 15 years old.  My questions deals with recharging the refrigerant.  How can I tell if I could eek out another 10-15%  in cooling by having it recharged?   How many of you have ever had your's recharged? Cost?   I have an IR temperature gun, and conventional thermometers, is there a benchmark test I should run?

[Nick Badame Refrig/ACC]

Hi Wayne,

It sounds like your system is free of refrigerant leaks as you said it cooled fine last summer. Adding more refrigerant then needed will only shorten the life of the

compressor as well as do just the oppisite of what you think. With a 15 year old unit the best thing you could do is clean the condencer and evaporator coils.

This will help the unit to berath better and in turn use less electricity. Short of that, an upgrade to a unit with a scroll compressor would use less juice..

Good Luck
Nick-

[Airbag]

Hi Wayne,

It sounds like your system is free of refrigerant leaks as you said it cooled fine last summer. Adding more refrigerant then needed will only shorten the life of the

compressor as well as do just the oppisite of what you think. With a 15 year old unit the best thing you could do is clean the condencer and evaporator coils.

This will help the unit to berath better and in turn use less electricity. Short of that, an upgrade to a unit with a scroll compressor would use less juice..

Good Luck
Nick-

Hey Nick
I had the same thought with my old Dometic but sooned learned there were no fittings to charge it with. By the way I took a peek at the new unit and it looks OK just a little soot and at first glance the coil appears clean. I was going to install it tomorrow but it rained pretty hard here today and I will have to wait to get it out of the yard because of mud.

[WEC4104]

Thanks, Nick.  It doesn't appear that I have any leaks, as I still get chilled air out of the unit, even with it's advanced age.  Given that I only have the one unit to keep us comfortable, it is important that I make sure she is running at her absolute best.  Cleaning the coils is the preferred answer anyway, since I can do that myself for free rather than incurring the cost of a recharge. 

[baker4106]

You might check air temperature in and out and post that.   That will tell some what the unit is doing.   High temp. difference means not enough air flow and low difference means too much air flow or low freon as a start.