Pipe Temperatures

[chuckcrj]

How would you go about that on a typical cased coil with a pen type probe?

Wouldn't be very easy or accurate in that situation. I was thinking of walk ins where the evap tubing is readily accessible.

[itsiceman]

Russell if you made a quick responding pen type probe for surface temps, I would buy it. Something that can clip in my pocket that I could take quick, accurate surface temp readings would be a huge value.

As said above, you can get SH without pressures.

How would you go about that on a typical cased coil with a pen type probe?

For a quick check wouldn't you focus on how the highside is running and just air temps across the evap coil anyway.
You can be running perfect SH with a messed up system.

[itsiceman]

Hey Dex Did you see the new Cooper thermocouple pipe strap in the RSES Journal?
Looks just like the Cooper 4011 thermistor pipe strap.
Bet you could get rid of the strap and make a small clamp out of it for those sizes you wanted. Not sure if it will do a hot discharge line with out melting. I haven't seen the spec but the 4011 isn't all that high.

[itsiceman]

Found it says 300 on the top end

http://www.cooperinstrument.com/prod...et.asp?pid=381

[RussellHarju]

Russell if you made a quick responding pen type probe for surface temps, I would buy it. Something that can clip in my pocket that I could take quick, accurate surface temp readings would be a huge value.

As said above, you can get SH without pressures.

This is the type of thing we thinking just for quick checks. I imagine a tech doing a basic walk around to get his bearings on the system and taking some quick measurements to get an idea of where to start the diagnostics.

To do the diagnostics he probably wouldn't be using the same pen tool, and would probably want to have his gauges, pipeclamps, airflow instruments, etc. to properly diagnose the system.

Am i on the right track about how you guys do the job?

[RussellHarju]

Russell, I work in residential and light commercial. I always hook up my gauges and check superheat and subcool. I use analogs with the srh2 digital psychrometer for pipe temps. I think the srh2 is a great tool but it would be even better with 2 k type plugs and the ability to show both line temps simultaneously. This would also make it so that you could check supply and return temp simultaneously as well. You guys probably already have a dual plug temp meter but I think it should come on the srh2 as well because we always look to carry as few tools as possible if we can help it. I also second a pipe clamp that can fit into smaller spaces. I've seen your new line of clamps have the spring break through the plastic when guys squeeze at the end of the handles. Two out of 6 did this at our shop. On the wireless scale it's not a biggie but with how beefy and tough the scale is I would like to see the plastic handle come with a rubber skin for protection from drops, just like how the srh2 had a rubber outer skin/boot.

Great info. I like the idea of have 3 temp measurements on one meter.

[Dr.phil]

This is the type of thing we thinking just for quick checks. I imagine a tech doing a basic walk around to get his bearings on the system and taking some quick measurements to get an idea of where to start the diagnostics.

To do the diagnostics he probably wouldn't be using the same pen tool, and would probably want to have his gauges, pipeclamps, airflow instruments, etc. to properly diagnose the system.

Am i on the right track about how you guys do the job?

Exactly, can you have one by the end of the month?

[itsiceman]

This is the type of thing we thinking just for quick checks. I imagine a tech doing a basic walk around to get his bearings on the system and taking some quick measurements to get an idea of where to start the diagnostics.

To do the diagnostics he probably wouldn't be using the same pen tool, and would probably want to have his gauges, pipeclamps, airflow instruments, etc. to properly diagnose the system.

Am i on the right track about how you guys do the job?

If the sensor will work just as good reading at reading air and liquid temps you will have something. Pipe temps alone is not enough info for a meaningful quick check. The testo works well for all three but the whole thing is fragile. Also would like to see a sliding shield for taking surface measurements around air movement and exposed for air temps. I think one sensor only especially if it is a TC is the only way to go with this. It's more accurate for taking differential temps. in the same environment.

[RussellHarju]

If the sensor will work just as good reading at reading air and liquid temps you will have something. Pipe temps alone is not enough info for a meaningful quick check. The testo works well for all three but the whole thing is fragile. Also would like to see a sliding shield for taking surface measurements around air movement and exposed for air temps. I think one sensor only especially if it is a TC is the only way to go with this. It's more accurate for taking differential temps. in the same environment.

Good info. Thanks!

[darctangent]

First let me say that I think it's absolutely brilliant of Fieldpiece to use HVAC-Talk as a sounding board for product development. I think there are a bunch of great creative guys here that would love to see some of their ideas realized and/or wants and needs met by a instrument company, so thank you Fieldpeice! I hope this proves worthwhile to you.

If the sensor will work just as good reading at reading air and liquid temps you will have something. Pipe temps alone is not enough info for a meaningful quick check. The testo works well for all three but the whole thing is fragile. Also would like to see a sliding shield for taking surface measurements around air movement and exposed for air temps. I think one sensor only especially if it is a TC is the only way to go with this. It's more accurate for taking differential temps. in the same environment.

Double down on the dittos for Iceman's post. If we are talking resi forced air application, then it really needs to do both air and pipe(surface) temps.

Let me firm up my concept of how this might work. First, the format of a retractable pen comes to mind, using the outer case to protect the sensor from damage. You click the "pen" and the sensor pops into view, and it turns on. It should be noted that the sensor, what ever it's makeup should be isolated from other masses to improve speed and accuracy of the reading. (I am aware that this is intended to be a fairly low budget item, but I would suggest some effort to do what can be done. Please see the testo and also the Fluke 80pk-8 as an example of trying to minimize thermal bridging) You can use the testo 550 pipe clamp as an example of how NOT to do it.

The sensor could be attached to the end of an collapsible pole (think 70's style antenna) so that it could extend into the duct something like 8-12" for air readings. It would be a plus if it had two additional features-

1) some kind of sharp point for cutting a small hole in the canvas connector.

2) memory for four readings- Return Air, Supply Air, Liquid Line, Suction Line

could be powered by AAA or button cell, AAA would be better.


BTW, I don't do a "walk around" currently, but if I had a tool like this I might!


I have been interested in somebody producing a dual temp thermometer for RA/SA for a while now, this has got me wondering if I should explain the idea to you Russell! I think it would be right up Fieldpeice's alley.

[itsiceman]

Russ is the SIL2 I/R pen style for these "pipe temperatures" you were asking about or is there still a true contact version in the works?




http://www.fieldpiece.com/PDF/Manual...n-SIL2-web.pdf

[chuckcrj]

Russ is the SIL2 I/R pen style for these "pipe temperatures" you were asking about or is there still a true contact version in the works?




http://www.fieldpiece.com/PDF/Manual...n-SIL2-web.pdf

I'm listening... I was wondering just a few days ago if anything came of it. I'm not interested in an IR type.

[RussellHarju]

Russ is the SIL2 I/R pen style for these "pipe temperatures" you were asking about or is there still a true contact version in the works?




http://www.fieldpiece.com/PDF/Manual...n-SIL2-web.pdf

No the IR really can't be used easily for pipe temps. Because the surface is metallic and reflects the light it won't give you accurate readings. And even if you cover with dull tape the it's difficult to measure a small area on a rounded pipe accurately. IR is meant for flat dull surfaces and usually just a "check".