manometers on a hvac system

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Old 07-11-17, 02:10 PM
O
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manometers on a hvac system

I want to use manometer on a heat pump to check it. I have 1/4" flexibles and the test port on high pressure side is very close to compressor exit and very hot. Is there any problem to connect to this "very" hot place _ will the manometer handle it ?
If the gas is colder in the manometer (on a 6 feet long flexible), it may condense ther maybe - any problem ?

thanks
oliver


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Last edited by PJmax; 07-12-17 at 11:15 AM.
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Old 07-11-17, 05:09 PM
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Welcome to the forums.

You need dedicated gauges to check refrigerant system pressures. Each type of system/refrigerant has it's own gauges.

A manometer is sometimes used to check very low pressures but is more commonly used to measure low level vacuum. It CANNOT be connected to anything with high pressure.

Why do you want to check the pressure ?
 
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Old 07-12-17, 12:28 AM
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Hi pete,

Thanks for answering but I have to comment a bit:
I received a long time ago a full education on hvac systems, but never practiced after.
On AC systems you use a double manometer for the low pressure side of the compressor (typically 0 - 10 bars) and high pressure side (4 - 30 bars). The manometers usually have multiple scales for different refrigerants (graduated in temperatures, as strange as it may seem, there's a direct relation between pressure and temperature for a liquid/gas mix of refrigerant).
From the measurement of the low and high pressure side of the compressor, you can get a full diagnostic of the system, and the power efficiency.
The point is I haven't practiced and on the system I want to check, the high pressure port gets very hot on running. I don't remeber if special care/handling apply.

regards
Oliver
 
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Old 07-12-17, 01:00 AM
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http://www.doityourself.com/forum/ai...ng-your-c.html

This site has a rule against assisting with the refrigerant side of the system.
It seems like any post on the subject quickly gets into details on charging.
 
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Old 07-12-17, 01:04 AM
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Yes.... I understand completely the dynamics of pressure measurements, high and low differentials and how temperature affects them but I have never heard of using a manometer for checking refrigerant pressures.

I have dual gauges for all the equipment I work on.

The high pressure side of the system can be between 250psi and 400psi depending on type of refrigerant and runs extremely hot.

I can tell you this.... it is the policy of the DIY administration that charging systems and pressures are not discussed in the forums as they require an EPA certified tech licensed in refrigerant handling.

http://www.doityourself.com/forum/ai...ng-your-c.html
 
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Old 07-12-17, 01:20 AM
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I think he is in another country. Manometer usually refers to a very different tool in this country.
 
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Old 07-12-17, 04:10 AM
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Yes, the term manometer in other locations is what we refer to as a gauge.
The pressures read with our manometer is in the range of inches of water column or inches of mercury depending what you are measuring.
A bar is about 15 psi so his low pressure manometer would read 0 - 150 psi.
 
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Old 07-12-17, 11:15 AM
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Added member location to the first post.
 
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Old 07-12-17, 04:05 PM
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I thought that in the EU a license was required to work on any refrigerant system.

The OP should take a refresher course before opening up any system.
 
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Old 07-13-17, 12:31 AM
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Hi again !

Thanks to all for the discussion. You're right : it seems that what I call "manometer" is a "gauge" for you - sorry for the misleading term.
I perfectly understand the rule about not discussing charging, as this is a hot topic as related to environment.
And then Astuff is right, in EU a "license" is required for the manipulation of refrigerants, but my "diploma" (not sure for the word) is regarded legally as an equivalent for the license. Of course, the suggestion of a refresher course is a wise suggestion.

Oliver
 
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