DIY A/C Refill/Recharge

[bmarshall1]

Hello A/C Gurus- My outbuilding has 2 HVAC units that have not been run since I purchased the property (@ 3 years ago). Yesterday I confirmed they will run and I want to get them working; they don't have to be perfect, as I only need something to cool the air in a FL outbuilding (30x60) while I'm in there.

Unit #1 - Trane XB 13, year 2006, Unit #2 - Rheem RAKA-042JAZ, year 2000

Unit 1 runs, but not cools, there seems to be no difference in temp between the hot and cold lines.

Unit #2 runs, does not cool, there is a SLIGHT temp differential btw the hot/cold lines outside (maybe 5 degrees). This unit also has a buzzing/bad electrical contact noise from the outside unit. I just looked and see exposed contacts, capacitor, and wasp nests, lots of wasp nests.

I am quite handy but have not done this before. I know many replies will be to contact a professional, but I can't justify $1,500 for 2 refills on a system that may not work for any length of time nor $8k for a new one. I can buy the equipment and supplies online for $300 and learn at the same time, and if one unit dies, well, I still have the other (I really only need one to work and will use them fairly infrequently). Both units are clean down in the condenser coil.

So... Since these are R22, should I use R22 again or use one of the replacements, if so which one?

Since both units still have pressure in the lines do they need vacuumed.

Should oil be added.

What about some sort of 'seal swell' conditioner (I have very good luck w/ it on a car one time, I know, different thing...)

Is it as simple as getting gauges, following directions, adding oil/seal swell, adding refrigerant, measure temp and done?

What are the main difficulties and any PRO tips to look out for. Thanks for any and all help.

 

[lbpd716]

Hi there bmarshall1

Not trying to be a jerk - but the fear of stumbling onto the situation you are describing here is one of the reasons I'm signing up for a HVAC class at the local community college once I retire from my day job in a few weeks. Just my opinions here.

There are MANY variables to what you have going on, and lots of specialized gear you will be needing to repair those units, and do it properly. It's not like the leaky hose in your car that needs a top off.

Vacuum pump, manifold set, refrigerant, scales and a decent meter (for A/C work I have a Fieldpiece HS35) are just some of the things you will be needing.

There is a lot to learn, and it's fun to learn these things. It's not an impossible task for the DIY guy. Check the availability of a class in your area at a community college and good luck.

 

[htmdude57]

I think Lbpd716 has a good suggestion. There is a lot to know about AC. Too much to describe in a forum post. In addition, a person needs to be EPA Certified (learn, then pass a test) to work with refrigerants. Release of refrigerant is punishable by a hefty ($10k?) fine.

 

[LS6 Tommy]

In a nutshell, you can't do legally it yourself. Now, tossing that out of the way, I'm all for DIY stuff, but from what I've read, your technical knowledge of it makes it something I wouldn't recommend to you as a DIY right away. Classes are a good idea. You won't be able to get what you need for $300.00, either.

There are no direct drop-in replacements for R22. All require system changes and retrofit work that is also probably a little over your head.

IDK where the $1500.00 number came from, but for right now I'd call a tech. It may be as simple as a leaking Schrader valve and recharging the system. If it's a hard to find leak or they just want to top it off, doing so is up to you. R22 units sometimes aren't worth saving.

Tommy

 

[theoldwizard1]

R22 is getting scarce, which means expensive. From Wikipedia

Beginning January 1, 2020: The Montreal Protocol requires the U.S. to reduce its consumption of HCFCs by 99.5% below the U.S. baseline.

As a DIYer, I doubt you can even buy any.

Things To Be Aware Of When Considering R 22 Replacement Refrigerants

At a minimum you would need to remove all R22, probably purge the system with nitrogen and then install the replacement refrigerant. Most substitutes do not work as well.

 

[bonneyman]

I'm a well-to-do DIY and have been in HVAC for over 30 years. There's only so much of the job that you can MacGyver through. Most people don't believe it, but there is some serious science involved that requires the 'touch", finesse, and experience.
I'd say talk to your friends, neighbors, and co-workers. Ask who they have do their A/C. Most companies are like doctors these days - get you hooked, and then bleed you dry. But there are still some guys out there like me who want to fix the machine and not just make a killing. You might not have the time to do as thorough a search as you'd like, but talk to those you know.

 

[Terry D]

Agreed, their are some many things it could be. The replacement Freon's for R22 require something's before they can be installed. MO-99 being one of them. You must evacuate all the R22 from the system, which requires special equipment and EPA certification, replace the filter dryer and then do a standard leak test, vac down and recharge. I believe, but maybe wrong, you do not need to be EPA certified to purchase this Freon. But a supply house still might not sell it to you if your not a contractor. I have heard people dumping this right on top the R22 in the system and not having a problem, but that is not the proper way of doing it

 

[bmarshall1]

Thanks for the replies, a class is out of the question for now. I know there are a lot of small variables and intricate knowledge and I'm not trying to short change the HVAC tech's on here, but based on what I have seen a handy person should be able to do a refill. Google says average price for a refill is $600 to $800 per unit, times that by 2, I'll call a local shop but doubt they will give me an estimate over the phone.

Many years ago I was told I needed a whole new A/C system for my car due to the freon changeover, so I said "F" it. I filled it with the new (at the time (R134?)) and it worked better that ever. I can change a clutch, rebuild a motor, I am my own electrician, plumber, mechanic, roofer, cabinet installer, tractor mechanic, I do my own alignments, I have repaired a dead refrigerator, fixed a pool leak etc... I hope you get the idea. One thing I am good at is learning, it's my passion.

A little research show me at least one replacement "RS-44b requires no oil or system component changes". So that aside, is this something anyone has done?

 

[Jim greengo]

In a nutshell, you can't do legally it yourself. Now, tossing that out of the way, I'm all for DIY stuff, but from what I've read, your technical knowledge of it makes it something I wouldn't recommend to you as a DIY right away. Classes are a good idea. You won't be able to get what you need for $300.00, either.

There are no direct drop-in replacements for R22. All require system changes and retrofit work that is also probably a little over your head.

IDK where the $1500.00 number came from, but for right now I'd call a tech. It may be as simple as a leaking Schrader valve and recharging the system. If it's a hard to find leak or they just want to top it off, doing so is up to you. R22 units sometimes aren't worth saving.

Tommy

There are plenty of drop ins that can be used on an empty/dry r22 system with no changes.
You just cant mix them with existing freon.

 

[Jim greengo]

Agreed, their are some many things it could be. The replacement Freon's for R22 require something's before they can be installed. MO-99 being one of them. You must evacuate all the R22 from the system, which requires special equipment and EPA certification, replace the filter dryer and then do a standard leak test, vac down and recharge. I believe, but maybe wrong, you do not need to be EPA certified to purchase this Freon. But a supply house still might not sell it to you if your not a contractor. I have heard people dumping this right on top the R22 in the system and not having a problem, but that is not the proper way of doing it

I'm not aware of any actual supply house that will sell you any freon without atleast an EPA card.
Other than maybe finding a jug on craigslist.

 

[brewchief]

R22 is available from sources like ebay, you have to verify that you are epa certified or purchasing it for use by someone who is, I would not use one of the replacements in this case especially with limited experience.

At a bare minimum you need a set of gauges and a digital thermometer, you will need to know what type of metering device each unit has so it can be charged properly via superheat or subcooling.

If they are both low on refrigerant then they both have leaks, how major of a leak is unknown at this point.

Looking at the factory charge listed on the nameplate will give you a general idea of how much refrigerant you will need assuming they are both nearly empty. An extra pound or two per unit wouldn't be uncommon depending on coil matchup and lineset length.

It's entirely possible that you could spend 400-500$ and have both working or they both could leak it all out in no time.

Sent from my SM-T510 using Tapatalk

 

[bmarshall1]

There are plenty of drop ins that can be used on an empty/dry r22 system with no changes.
You just cant mix them with existing freon.

This is the info I am collecting - is there a drop-in that is best/easiest?

Once again - no disrespect to any HVAC guys, and I am likely oversimplifying this, but with a manifold set, temp gauge, leak detector, and some Internet knowledge, it would seem that adding some R22 (assuming I have some) on a system (assuming no diagnosis) is doable?

Would I need to weigh the charge I am putting in, or could I look for temp differentials etc...

 

[Terry D]

I'm not aware of any actual supply house that will sell you any freon without atleast an EPA card.
Other than maybe finding a jug on craigslist.

I didn't really know, just going by what I've heard. I'm EPA certified, so I don't have a problem. Some one told me that you can buy 410a without a license also, don't know how true that is. I do know, I just ordered a MR Cool unit through Home Depot for my garage, Its not the DIY model, Its the professional install one. It comes precharged with 410a and I did not have to prove any EPA certification, but on the other hand, I needed a burner control module for a furnace, had nothing to do with Freon and had to show my card at a supply house in order to buy it.

 

[SALIV8]

This is the info I am collecting - is there a drop-in that is best/easiest?

Once again - no disrespect to any HVAC guys, and I am likely oversimplifying this, but with a manifold set, temp gauge, leak detector, and some Internet knowledge, it would seem that adding some R22 (assuming I have some) on a system (assuming no diagnosis) is doable?

Would I need to weigh the charge I am putting in, or could I look for temp differentials etc...

I would add to that list a vacuum pump (if the system is empty) and Compatible leak stop. If empty I’d replace the Shader valves also and caps.

They have a small leak stop hose now that you can add to your gauges.

But first, make sure Of the basics: the condenser fan is running and the compressor is running. Clean the coils. Make sure the indoor fan is running. Sometimes pouring warm water over the expansion valve/txv can unstick them.

Could be a bad capacitor or contactor. The system is not suppose to leak out. Good chance you need no refrigerant.

 

[dacuda]

freeon for older systems is 100$ plus per pound which is very expensive to fill a system. ac guy told me i had a leak in my system but couldn't tell me where and wanted to sell me a new system for 8$grand.i recently sold a house that had a 22 yr old system that i was told needed replacing 3 different time over 18 yr span and just added some freon and was good. found a guy thru a friend and he filled it for $100 bucks.just ask around and you will find someone who knows someone who does ac work.i will never pay a guy from a big ac company to do work on my house.most guys do work on the side for less than half the cost.i live in florida so most companies know in the middle of summer people will pay any amount to have cold ac.

 

[Gotcha640]

How will you pressure test to make sure that you don't pump new, expensive freon in to a wide open line?

Depending on where you live, maybe there are companies that do free diagnostics, and you could sweet talk them long enough to tell you exactly what's wrong before you tell them no thanks. Not exactly ethical, but I've done similar to an auto mechanic.

Other choice on a cheap call would be a one man operation, tell them on the phone you're only interested in paying for an hour of diagnostic and a few dollars in parts.

My house, the ac buzzed so bad a month after we moved in, we moved out of the master bedroom for the summer. The following summer, we called a guy, who told us the lines were just touching the wrong thing, a p clip to hold them in the right place took care of the buzzing, and he pressure tested the system, checked out the attic unit, and made suggestions on where to spend money to make the most impact. Totally fair for $55.

 

[danski0224]

I am quite handy but have not done this before. I know many replies will be to contact a professional, but I can't justify $1,500 for 2 refills on a system that may not work for any length of time nor $8k for a new one. I can buy the equipment and supplies online for $300 and learn at the same time, and if one unit dies, well, I still have the other (I really only need one to work and will use them fairly infrequently).

Well, if you can get the stuff to fix it for $300, what are you doing wasting your time here?

 

[bmarshall1]

Well, if you can get the stuff to fix it for $300, what are you doing wasting your time here?

Well, as Dirty Harry said "A man's got to know his limitations", and I am lookingg for mine, but you knew that, right?

As luck would have it I received in the mail a HVAC check up for $29, I also know the whole idea is to up-sell me but as long as the price is in line for the work I will have them come out and post results.

I cannot believe that with all the DIY'ers on here no one has done this before.

 

[kneeman]

Well, as Dirty Harry said "A man's got to know his limitations", and I am lookingg for mine, but you knew that, right?



As luck would have it I received in the mail a HVAC check up for $29, I also know the whole idea is to up-sell me but as long as the price is in line for the work I will have them come out and post results.



I cannot believe that with all the DIY'ers on here no one has done this before.

Check your messages

 

[danski0224]

I cannot believe that with all the DIY'ers on here no one has done this before.

You can download the factory provided kneepads (the instruction manual) and actually read how to install the units correctly.

It really wouldn't matter what brand, the installation is pretty much the same.

The factory provided kneepads also cover charging.

If there is industry specific terminology that you do not understand contained within the kneepads, there is this thing called Google that will assist.

 

[Earp69]

i recharged my old system twice to keep her going,each time i charged it it lasted a couple years atleast. i have no prior training in hvac,just hooked up the gauges and let the juice flow until your line starts to frost is what i did. if i was closer i would sell you some r22 for a reasonable price.i have 45 pounds i need to get rid of

 

[Balvar24]

If the system is out of R22, what has replaced it? Unless it was under a vacuum, the answer could very well be non-condenseables.

Got a bottle of nitrogen? Pressure test it. Find where it leaked out. Repair leaks. Hire someone with equipment and knowledge to pull a good vacuum and re-charge.

As stated before, R-22 is getting higher every day.

 

[danski0224]

As stated before, R-22 is getting higher every day.

Not really.

 

[Terry D]

Well, as Dirty Harry said "A man's got to know his limitations", and I am lookingg for mine, but you knew that, right?

As luck would have it I received in the mail a HVAC check up for $29, I also know the whole idea is to up-sell me but as long as the price is in line for the work I will have them come out and post results.

I cannot believe that with all the DIY'ers on here no one has done this before.

Dont expect a whole lot for 29.00

Sent from my SM-G960U using The Garage Journal mobile app

 

[Rusty Fords]

$29 show up at door and confirm you have a/c

 

[bczygan]

I just finished 2 classes of automotive HVAC at the Jr. College.

I thought HVAC was simple. It is and it isn't. And there is a reason there are laws requiring you to be certified to work on it.

Bill

 

[jjrbus]

Get a tech they said. I am in SW Florida and AC service here is horrible, worst thing I have ever seen. The bulk of them are smash and grab types. I am sure there are good honest techs out there but they are very difficult to find! This applies to auto AC also.

I am retired and learn as much as I can about AC and have spent hundreds on tools to do as much as I can by myself. Spent hundreds and saved thousands!

 

[nadogail]

While you are in school, cultivate your instructor and after developing a relationship ask your instructor for guidance.

 

[Gila Monster]

If it really is just a few pounds low on R22, this should be an inexpensive repair for a tech, but it's hard to find ones that don't just want to sell you a new unit or want to gouge you. The $100+ a pound nonsense is a game I just won't play, did that one time and then learned how to do it myself and bought my own tank. Had an elderly relative where they charged like $1,500 to just add R22. You can get a tank for $350.

I had an honest tech that I really liked, but he retired. Found a new one through a recommendation, but he's close to retirement also. Asking around is the best advice.

 

[theoldwizard1]

... with a manifold set, temp gauge, leak detector, and some Internet knowledge, it would seem that adding some R22 (assuming I have some) on a system (assuming no diagnosis) is doable?

You forgot vacuum pump. Assuming they have no refrigerant, the first step is to pull a vacuum and see if it holds. Probably not (if there is no refrigerant, where did it go). Soldering condensers/evaporators is a hit and miss even for pros which is why they usually get replaced.

You probably should have a micron gauge (special, very low vacuum gauge) also.

 

[theoldwizard1]

freeon for older systems is 100$ plus per pound which is very expensive to fill a system.

Surprisingly, you can get a 30 lb bottle of R22 on eBay for <$400 including shipping.

 

[theoldwizard1]

How will you pressure test to make sure that you don't pump new, expensive freon in to a wide open line?

You start by pulling a vacuum. If it won't hold a vacuum then you know it has a leak.

Many (?) pros will also use nitrogen to pressurize the system. Do they make nitrogen detector wands ?

 

[theoldwizard1]

I just finished 2 classes of automotive HVAC at the Jr. College

The biggest issue now a days with auto A/C are all of the "extra" safety devices that prevent the actual compressor clutch from engaging. Some are wired in series with the clutch, but some are just inputs to the PCM which decides when to engage the clutch.

Although 12VDC powered refrigerant compressors do exist, the existing technology in automotive refrigerant compressors make them dirt cheap.

 

[theoldwizard1]

Neighbor's step son is a tech. Case of beer and buy your own refrigerant.

 

[Bigblockyeti]

Soldering condensers/evaporators is a hit and miss even for pros which is why they usually get replaced.

My brother had a tech come out and add 4.5lb and check everything out on both units for $350 NW of ATL. He found a pin hole worth about 1.5lb per year and my brother in his infinite wisdom fixed it with JB Weld. I didn't think it would hold but it is, sort of. The annual checkup is now ~$150 covering both and adding usually a pound to the one with JB Weld on the evap coil. I think $150/yr. limping it along and have it still perform well isn't a bad deal, especially compared to $6K for one and $8K for the other to be replaced.

 

[Gotcha640]

You start by pulling a vacuum. If it won't hold a vacuum then you know it has a leak.



Many (?) pros will also use nitrogen to pressurize the system. Do they make nitrogen detector wands ?

I know how it's supposed to be done, I'm asking the OP how he intends to do it. We get a lot of these types of questions where the plan is to use whatever is in the garage, usually a screwdriver and an ax and a watermelon.

 

[bczygan]

I just finished 2 classes of automotive HVAC at the Jr. College.

I thought HVAC was simple. It is and it isn't. And there is a reason there are laws requiring you to be certified to work on it.

Bill

By the way.........I just took the test and got my 609 certification at 1:30 this morning!

Bill

 

[firebirdparts]

I cannot believe that with all the DIY'ers on here no one has done this before.

This subforum here is really for professional advice (I guess). This and the other specific subforums generally have a pretty high level of expertise.

Here is what you must do:

1. Figure out if your compressor came on. Why or why not? Most of the time, when an a/c won't cool, it's a $15 capacitor. If the compressor's phased locked, yeah, it's going to sound funny. You be the judge, but I think I fixed one of them just with that.
2. if you can get the compressor and two fans running, then you can enjoy a beverage while you wait to see if it gets cool. No? Put on the gauges. You should easily find information about what the pressure should be.

if you need freon, then call somebody. Don't call them until you fix everything but the freon yourself.

 

[Showkey]

By the way.........I just took the test and got my 609 certification at 1:30 this morning!

Bill

In 40 years nobody as ever asked to see that certificate

 

[LS6 Tommy]

There are plenty of drop ins that can be used on an empty/dry r22 system with no changes.
You just cant mix them with existing freon.

There may be something new on the market, but to my knowledge any that are EPA approved need to have the oil removed and replaced.

Tommy