Understanding IR

Specific Inspection Topics Thermal Imaging, Infrared Cameras & Energy Audits
#1

Explain this image if you even think you understand IR

I was playing with a heat pump Monday and shot this image for fun and got to looking a little closer in the office.

The HP was in operation at the time the image was taken the exterior ambient was about 50 degrees F Notice the compressor temp above 200 degrees the surface temp of the dischage line out of the compressor drops to about 65 F and then the inline dryer temp is 201 F. The discharge line between the compressor and the dryer is roughly 6 inches in length. Explain the temp differential between the compressor and the dryer;-)

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#2

Different material, different emissivity.

Jeff

#3

Are you saying the emissivity difference between painted steel and shined copper is over 100 degrees

#4

I don’t understand IR but I love guessing! Does it have anything to do with acid?

#5

May be on to something here…A collecting of hot fluid would be hotter than a stream of it. And painted material might not dissipate heat as quick as unpainted. Does copper dissipate heat quicker than steel?

#6

[quote=“jjimenez, post:4, topic:74162”]

I don’t understand IR but I love guessing! **Does it have anything to do with acid?/**QUOTE]

Your in left field the ball is in right field;-) why would you think acid I don’t understand

#7

[quote=“cbottger, post:6, topic:74162”]

Lol no point in being in the wrong field and then tripping and falling on my face.

#8

Tell him what the RAT was.

Jeffrey & all - you can prove / disprove what Charlie is asking by manipulating the emissivity and reflected temperature settings on your own imagers OR you can download Charlie’s image (it is radiometric) and do the experiment with FLIR tools such as any one of these that you can access for free whether you have an imager or not. Of course you will need to do your own research into typical emissivities of the materials…

http://www.flir.com/thermography/americas/us/view/?id=58384

#9

Yes copper does disipate faster than steel so your thinking 6 inches of copper would drop the temp 140 degrees.???

I don’t understand hot fluid and or Stream

When I think about Freon and the State of it I think in terms of liquid or vapor

#10

Liquid is hotter than gas but the fan is not running to help remove heat

#11

Questions to consider: So what happens as a liquid changes state from liquid to vapor and back again???

Ask Mr. Refrigeration: Does the refrigerant change state between the compressor and the dryer?

#12

From liquid in compressor to gas or vapor in dryer

#13

Now you guys are thinking!!!

Fundamental laws of physics are vitally important regardless of the application for IR.
Without that knowledge… you’re just “looking around”. :wink:

#14

Ya got it backwards the vapor is hotter than the liquid because it was just compressed by the compressor and has not been turned to a liquid until it reaches its condenser. The fan was operating at the time the image was taken

#15

OK so the heat of the liquid and gas refrigerant plus the temp of oil and electrical motor in compressor makes it hotter?

#16

No change of state its operating in the heat mode it leaves the compressor in a hot vapor and remains in that state until it arrives at the indoor A-coil where it transforms back to a liquid

#17

No liquid in a compressor or at least there is not suppose to be if there is ya have a problem. Compressor take low pressure low temp vapor and creates high pressure high temp vapor that is all they do period

#18

Oh well

#19

Go back to post #8

Think about the thermal properties of polished copper i.e., conductivity, emissivity/reflectivity…

Think about why copper clad pots and pans are so popular…

#20

Not going to help ya much think about what I said (the unit was operating in the heat mode at the time the image was taken) that is the main key ya need to fully understand the operation of a heat pump before that image makes much sense IMHO