best technique opinions

[Michael Inwards]

please give personal opinions of how to best measure temp differential on ac split system. laser gun doesnt seem to be accurate for me....perhaps I have a bad one, or doesnt like trying to pull temp from a reflective surface, I dont know....but would like other ideas

[Bob Elliott]

Then use a traditional thermometer or learn to not hit the reflective materials.

Bear in mind that the closer you are the more accurate you are since your measurement cone radiates.

[Robert J. OConnor]

For info on temp splits see these topics ...

http://www.nachi.org/forum/f20/ac-splits-yea-nay-3809/
http://www.nachi.org/forum/f20/check...entials-51388/

And about taking the readings try one of these ...

[David A. Andersen]

There is one and only one way.
Get a hygrometer and a Psychrometric chart...

[Dale Duffy]

Originally Posted by dandersen

There is one and only one way.
Get a hygrometer and a Psychrometric chart...

If the suction line is as cold as the Beer I like, its working....

I like Cold Beer.

[David A. Andersen]

Who taught you that?

Do you bring a "reference" beer to the site (lord knows you need one after some of those love shacks)!??

[Michael Inwards]

thanks for replies....though dales beer test may be the most unique approach i feel i benefitted the most by following robs links to past discussions regarding the topic. it appears that there is a wide variety of opinion weather one should even test split in depth at all....and pretty much figure if theres cool air coming out of the registers thats good enough....taking into account the myriad of possible variables along the way. ok thats cool....(little pun there) techique at kaplan by that particular instructor was inserting a thermometer right before intake (at the furnace) and somewhere right after evap coil but i just wanted opinions on how to do this, (he claimed in his eleven years of inspecting results are almost invariably 18 degree split) or other methods....or if other folks had any luck with laser thermometer. i believe i can establish a subjective technique with the provided input.
thanks
mike in MN

[Robert J. OConnor]

Originally Posted by dandersen

There is one and only one way.
Get a hygrometer and a Psychrometric chart...

Not for your average home inspector (lets not get started on that again) ... ... but if they want to try, the following is a link to a pretty good article on psychrometrics from ASHRAE ... http://www.handsdownsoftware.com/Ove...hrometrics.pdf

BTW ... for someone who's not an engineer I am very impressed with your technical knowledge about the mechanics of heating and cooling systems.

Originally Posted by dduffy

If the suction line is as cold as the Beer I like, its working....

Thats one of the big things I teach my students to look for. They like the analogy, and always ask if they can bring some "reference material" when we get to the practical field training part of the classes ...
.