HVAC gauges for home AC?

[plain garage]

We have an old Goodman central AC in the house, the air is not cooling. I suspect the refrigerant is low, but want to confirm before calling an HVAC tech. What would be a reasonable (read not cheapo, but also not too expensive) set of gauges to take some measurements? The Goodman unit uses R22, but I'd prefer one that reads 410A as well. Thanks.

 

[PelicanPines]

I like the Yellow Jacket gauges. It reads both R22 and 410A. I got mine thru Amazon.com. You will need to learn how to prime the hoses, etc. You don't want contaminates in your system.

You will also need to learn how to read the guages. Outside temp vs readings, etc. You should also look into an EPA certification in order to safely use them.

 

[Rookie2]

how are you going to tell if its low ? pressure readings are dependent on inside/outside air temperature . The a/c guy i know has a gauge set for each .

 

[LS6 Tommy]

Technically, you can't buy a gauge manifold set if you're not EPA certified, but in my experience most supply houses don't ask for your card unless you're trying to buy refrigerant.

Tommy

 

[Trey T]

edit for Tommy: you can buy the manifold set but technically you can NOT use it to service your HVAC system w/o being EPA certified

Technically, you can't buy a gauge manifold set if you're not EPA certified, but in my experience most supply houses don't ask for your card unless you're trying to buy refrigerant.

Tommy

 

[Mike007]

If you want to use a set of service gauges properly, you really need a temperature probe also that can read the temp of the refrigerant lines. You would need to understand superheat for a 22 Goodman system. It's not rocket science.

 

[Strouty]

If you want to use a set of service gauges properly, you really need a temperature probe also that can read the temp of the refrigerant lines. You would need to understand superheat for a 22 Goodman system. It's not rocket science.

That doesn't sound hard.

 

[Mike007]

That doesn't sound hard.

Are you being sarcastic? It really isn't that difficult to attach a temp probe to the suction line and read the temp.

 

[Strouty]

I was talking about understanding john goodman's 22 super heat. (yes a little sarcasm too.)

 

[Mike007]

I was talking about understanding john goodman's 22 super heat. (yes a little sarcasm too.)

So you find superheat hard to understand?

 

[Strouty]

So you find superheat hard to understand?

I find I don't know what you are talking about and I was too lazy to google it.

I do know it is super hot in my shop right now without AC, does that count?

 

[Mike007]

I find I don't know what you are talking about and I was too lazy to google it.

I do know it is super hot in my shop right now without AC, does that count?

That's pretty close.

 

[Strouty]

That's pretty close.

I figured. I do need to start learning, after finding out what they charge to repair my AC I am thinking about a new career.

Can you just take the EPA certs or is there actually a formal training requirement?

 

[Mike007]

I figured. I do need to start learning, after finding out what they charge to repair my AC I am thinking about a new career.

Can you just take the EPA certs or is there actually a formal training requirement?

It's been a long time, but I'd say you can just take the test. There was no technical info on the test when I took it back in 1990. I was all about the environment and the requirements to protect it.

 

[Trey T]

Well, I find it very hard to understand. I took two courses of thermodynamic over a decade ago but refrigerant stuff never sunken in. I have to research it once in awhile

So you find superheat hard to understand?

 

[justsam]

I have to keep it in my head that I am not making something cold, but rather removing heat, than the formulas work.

 

[LS6 Tommy]

edit for Tommy: you can buy the manifold set but technically you can NOT use it to service your HVAC system w/o being EPA certified

Very well put!

Tommy

 

[LS6 Tommy]

If you want to use a set of service gauges properly, you really need a temperature probe also that can read the temp of the refrigerant lines. You would need to understand superheat for a 22 Goodman system. It's not rocket science.

If he doesn't want to learn to check superheat, he can always go "Old School" and just get the suction pressure to line up with the return air temp, then charge a little more 22 until the suction line starts to sweat...

Tommy

 

[Mike007]

If he doesn't want to learn to check superheat, he can always go "Old School" and just get the suction pressure to line up with the return air temp, then charge a little more 22 until the suction line starts to sweat...

Tommy

Or "Charge it until it's sweating right to the compressor"

"Charge it until the suction line is really cold"

Or my favorite "Look for 75 on the suction side".

I was told all of these and I'm sure others when I was stating in the trade.

 

[Mike007]

Oh yeah, and this one really screwed me up, "Charge it until there is a 20* split across the evap coil." Being new and not knowing CFM, humidity and a few other factors affect the split across the coil I heavily over charged the system and never got to 20*.

Luckily at some point I realized all these "seasoned pro's" I looked up to really didn't have a clue.

 

[plain garage]

I like the Yellow Jacket gauges. It reads both R22 and 410A. I got mine thru Amazon.com. You will need to learn how to prime the hoses, etc. You don't want contaminates in your system.

You will also need to learn how to read the guages. Outside temp vs readings, etc. You should also look into an EPA certification in order to safely use them.

Thanks for the advice. Yellow Jackets look like quality products, is there any difference between the Brute II vs Titan lines? Is the compact ball ends (#49968) necessary or will regular hoses be fine (#49967)?

Technically, you can't buy a gauge manifold set if you're not EPA certified, but in my experience most supply houses don't ask for your card unless you're trying to buy refrigerant.

Tommy

I did not realize you need EPA cert to buy the gauges, only they won't sell you refrigerant without the license. I need to educate myself more on the topic, but essentially trying to avoid having to be sold a new system if it's an easier fix.

 

[danielzig]

I also recommend the Brute II. It is what we use at work and have taken some punishment. I just received a second home set of the 410A variety with liquid filled gauges. They are sweet!

Don't skimp. Get the ball valves on the end. I prefer the variety with the short hose piece prior to the valve as opposed to the kind where the valve is directly on the end. It makes access easier.

 

[LS6 Tommy]

Can you just take the EPA certs or is there actually a formal training requirement?

You can take the test on line or in a mail-in format, but the passing grade is 84% for those testing methods. The proctored test passing grade is 70%. I'd check out your local Votech school. They sometimes have adult courses.

BTW, I've been very pleased with my Imperial 600 series manifolds & low loss hoses. I've only had to rebuild one valve in at least 20 years and that's for all 3 manifolds I own.





Tommy

 

[brewchief]

I've got a couple sets of yellowjackets and one set of the imperial, both are fine.
Anything that's not super cheap should be fine for home use, riding around in a service van will be far harder on them then hanging in the garage.

 

[RTUmark]

Buy a fieldpiece sman3. You won't be disappointed.

 

[LS6 Tommy]

Buy a fieldpiece sman3. You won't be disappointed.

Not to discount the tool, but I think it's a LITTLE out of the "home use" range...

Tommy

 

[98ssuck]

A yellow jacket series 41 fits your needs very well. Pair it with some yellow jacket ball valve hoses. Ball end hoses are very important as it will reduce refrigerant loss. A must on critically charged ac units.

 

[LS6 Tommy]

A yellow jacket series 41 fits your needs very well. Pair it with some yellow jacket ball valve hoses. Ball end hoses are very important as it will reduce refrigerant loss. A must on critically charged ac units.

A Yellow Jacket 41 would be good, although I prefer the low loss hoses that allow you to attach the hose ends onto the port without it leaking as you screw them on and off.

Tommy

 

[kaffine]

Not to discount the tool, but I think it's a LITTLE out of the "home use" range...

Tommy

I just got a Digi-Cool AK900 for home use. Don't see why an SMAN3 is out of the question. Now if he had said a fully loaded iManifold with the smart phone app that might be a bit much for a homeowner. Then again I can't see most professionals buying that either since they tend to want to justify a tools cost.

EPA certified for both mobile and stationary. Never worked in the HVAC field and have no plans to however I maintain all of my own equipment. I also have a recovery machine, vacuum pump and micron gauge. Next on my list is nitrogen purge equipment and torch set. I am a very avid DIY.

 

[dclassical]

SMAN3 is on my to-buy list and just for my home use. Not having to manually calculate subcool (or superheat) and having a micron gauge incorporated makes it worth it for me. Amazon just reduced the priced on it too.

 

[LS6 Tommy]

I just got a Digi-Cool AK900 for home use. Don't see why an SMAN3 is out of the question. Now if he had said a fully loaded iManifold with the smart phone app that might be a bit much for a homeowner. Then again I can't see most professionals buying that either since they tend to want to justify a tools cost.

EPA certified for both mobile and stationary. Never worked in the HVAC field and have no plans to however I maintain all of my own equipment. I also have a recovery machine, vacuum pump and micron gauge. Next on my list is nitrogen purge equipment and torch set. I am a very avid DIY.

Good for you, man! It's nice to see someone who is willing to do it "right" just because...

Tommy

 

[brewchief]

I've seen way to many failures of digital gauges to jump on that bandwagon, I would rather see a quality digital thermometer with a pipe clamp probe and a separate vacuum gauge then a high priced set of gauges that may or may not work next year when you need them.

I like to keep my eggs in separate baskets whenever possible.

FWIW I'm still using the yellow jacket manifold set I bought in 1997 and a cooper digital thermometer from the same time, both still get used daily, I doubt a set of digital gauges will make it that long.

 

[jad3675]

SMAN3 is on my to-buy list and just for my home use. Not having to manually calculate subcool (or superheat) and having a micron gauge incorporated makes it worth it for me. Amazon just reduced the priced on it too.

You know, the sman4 is just 80 more and the sman460 was just released...

John

 

[dclassical]

You know, the sman4 is just 80 more and the sman460 was just released...

John

I see the SMAN4 at $120 above SMAN3 (at $320), but when the time comes I will look again.

I must say I had not looked at A/C tools in a while and I need to do some reading again. I find it a very interesting field.

 

[kaffine]

Good for you, man! It's nice to see someone who is willing to do it "right" just because...

Tommy

Thanks. I figure it costs more to do it wrong the first time.

 

[RTUmark]

Not to discount the tool, but I think it's a LITTLE out of the "home use" range...

Tommy

I think it works better for home use with superheat and subcooling calculations. The average joe checking system once or twice a year has everything he needs in one tool.

 

[dclassical]

I agree with RTUmark. For me it is the ease for use... no need to look up tables and do calculations (though really basics).

With SMAN3 take the measurements and enter them and you get your target superheat (which is what I need). You can redo the measurements as time goes by.

With the SMAN4 and accessories, you get real time wet bulb (inside - return air) and dry bulb (outside by condenser), so your target superheat is updated. Ease of use. Less prone to making a mistake.

 

[LS6 Tommy]

IDK what the big deal with the "calculations & tables" is that I'd want/need ridiculously expensive digital gauges that may be unreliable. Two of these & good gauges has gotten me through without failure for over 10 years...



Tommy

 

[kaffine]

I hadn't seen a thermometer setup like that. I am assuming the brass assembly is a valve core remover setup and then you put the thermometer in instead of the valve core to get a good temp reading? Then a side port to attach your gauges?

I was looking at getting separate temp probes and an analog gauge set but there wasn't much difference in price so I went ahead and got the digital gauges. The Digi-cool ones had good reviews. It limits my flexibility a bit since the temp probes are part of the gauge setup and not separate tools but I think the ease of use will make up for it.

For those with the SMAN 3 or 4 how do you like them?

 

[RonRock]

IDK what the big deal with the "calculations & tables" is that I'd want/need ridiculously expensive digital gauges that may be unreliable. Two of these & good gauges has gotten me through without failure for over 10 years...



Tommy

I'm bumping this thread to ask about this setup. Is this stuff still available? Where?