Show and Tell Time

Ok you shutter bugs tell me what you know, I am going to provide just a little info here, you fill in the rest. Two pics of the suction and liquid dryers on a operating A/C unit that has been operating for approximately 15 minutes. Outside ambient 65 degrees or there abouts and rain on and off. I scanned the dryers and you are looking at what I observed. Tell me what you see would it send a red flag or would it be of no concern , what further action would be required or necessary by the Hi to ensure you are providing accurate information to your client.
I have additional pics I will post when I get a good answer. :wink:

Should be of be of no concern.



Is that suction dryer hooked up to anything?

Sure is the unit was operating just buried in leaves:D I would not mess with you buddy;-)

I see both suction and liquid too close in temp with each other.

Proper suction pressure is 70# psig is about 41 degrees f.
We should have a 10 degree superheat at the coil and about 15 at the compressor. So 56 deg f is the most we should see; you have 68.5.

Liquid line is too hot for outdoor ambient.

“Blocked condenser coil” or if it were a heat pump, leaking reversing valve.

Not a heat pump and the condenser was clean.

My point of this thread was to indicate that the IR camera can make a reasonable replacement for the refrigeration gages that HI’s do not use if one knows what to look for.

Geez I posted a simple question and everyone ran from this thread like rats from a burning barn Whats the deal do I have a social disease I know I used my right guard this morning:D Don’t we have any IR/HVAC guys.</IMG>

You can’t get quantitative (accurate temp readings) from the camera of you do not tune it properly. What is the emisivity of the paint on the dryers? What about the ground thermal conductivity? Reflectivity? etc.

In any case, why use a complicated, hard to tune, instument when you can easily use a dual electronic thermocouple meter.

I will admit that a picture can be useful in helping to (visually) explain things to your client, but that delta T is not quantitative.

A good, general, indicator, but you really have to get down and take thermocouple readings of the lines to be accurate.

Just my opinion.

You do not need accurate readings the thermal pattern will work just fine as in the case of the image I posted I just used the camera which was handy at the time. To be trueful I already new this system had a problem before I ever broke out the camera because I had used my hands to feel the dryer and did not need an electronic thermocoupler either. The dryer felt to the touch almost as warm as the liquid line due to the rain that was falling at the time. That dryer should have been down in the 40’s to the touch and would have indicated very blue to the camera not even close to the 68 degrees that was indicated by the camera. I was not checking superheat temp where accuracy is important was just making the point the camera can be used as a quick indicator that something is wrong but yes so can your hand. You do not have to tune the camera for this can leave it on auto for that matter.

Oh by the way my Buddy David A. missed this one also I am going to post the pics of what I found because of this warm dryer. Whom beside David can tell me what is happening;-) Before Bushart comes along I do not consider removing 4 screws in the front of a A-coil exceeding SOP I consider it a normal excess panel.:smiley:

My poimt was that the camera could not be used, for quantitative evaluation, unless you tuned it.

since you already knew that there was a problem, you would probably only be using the IR picture to explain to the client.

I would not do that because, if I ever got sued, I would be opening myself up to a boatload of liability.

Good for a quick scan, but I would back it up with quantitative data by other means.

Just to clarify.

You are hung up on quantitative there was no intention on my part to determine quantitative. I just used the image to point me in the right direction as to a known problem. Any HVAC person in their right mind would not dispute the ice on the A-coil as not being a problem, the iced up coil was the Digital pic that I used in my report not the IR pic of the dryer. The Ir pic of the dryer was for my own use and to stirr up the thinking of this BB

BTW I have been looking for almost a year now of a dryer of this nature to show on this board they are not very common. I am also on the look out for one that has a restriction as it will have a different thermal pattern

I can’t play no more! :sad: ??

Good post Charley!!


Sorry if I offended you, Charley. Just trying to play the game you set forth.

You presented and image and asked us to interpret it, but without the necessary data.

From your previous posts, it was clear that you had more information, but wouldn’t share it as part of the problem.

You did an invasive inspection (and there is nothing wrong with that if you know what you are doing, and you seem to) but, that was not the presented problem.

What you implied with your first post (go back and read it) is that the IR camera would tell you something that you could not find other wise, yet you had already found it by other means.

Therefore, the use of your image was, and only slightly, helpful to the client and was not helpful to thermographers on this board.

You set up a test that was not really helpful.

That was my point. Sorry if you are offended (I got a red).

Hope this helps;

Will I don’t get offended and I don’t play the red game. But I disagree that the image was not helpful to my client because it was, he never knew what led me to discover the frost. He **is **going to get the A/C repaired because of what I discovered.

I can guarantee you if the Thermographers on this board would scan the suction dryers and if they find a nice yellow or red one there will be a problem I am sorry that you seem to have no knowledge of HVAC. I can teach you if you will just listen. Don’t get offended this is how the cow ate the cabbage:D :smiley: :smiley:

I suspect a blocked or restricted orifice tube or expansion valve… am I close?

Great discussion Charley!

You are right Bill I suspected the TXV was bad the A-coil was what we refer to as a starved coil when it is frosted but It could also have been low on refrigerant and I would not have know which unless I was actually troubling shooting which I did not do. Just viewed the A-coil the covers were already split 4 screws to let me have a peek that way when the HVAC tries to tell a different story I have the proof in hand. I have followed so many Hvac tech that miss bad TXV valves and just start adding more freon which does nothing but flood the condenser. I hope when you see those big old suction dryers in use that you will at least
feel for temp but it is so easy to use the IR camera for this it just jumps right out at you. E-value and reflective temp will have little to nothing to do with this.

BTW I did not write in my report that I thought the TXV was bad or it was low on freon my statement was. The A/C unit does not appear to be performing as intended and I showed the digital images of the frosted A-coil. Let the Tech make his own decisions as to what is wrong but he better be right.

Actually the frosting near the TXV was what narrowed it down, but the thermal image made me think restriction in the line somewhere. I actually often forget to use the camera on the A/C and lines… but of course we’ve only had a few days so far this year that we could use A/C.

I agree… qualitative has nothing to do with it. What we are looking at is all merely relative temps. You sure as heck can’t tune an IR thermometer for emissivity and most of us used those prior to a thermal camera.

(Sorry Will, I’m just not following your arguement on this one.):slight_smile:

Anyway, like I said… great discussion and made me put my think cap on which is what we should be doing anyhow when we use a thermal imager.