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# R-22 Conversion

Member Posts: 66
I take it you are using the professor pressure enthalphy
chart.
That where he left us in the dark, just like the mfg does when it comes to compressor hp.
I just use 1hp for every 12000 btus and it seem to fall into place for me.

• Member Posts: 1
R-22 Conversion

How do i convert R-22 Tonnage over to HorsePower?
• Member Posts: 2,343
Great info

GO to Ask.com "Convert Btu's to hp", = 12000BTU/HR =4.72 HP, Watts 3,516.85, KW 3.5 etc...

Mike T.
• Member Posts: 66
Hi Mike

Hows ya doing? I'll tell you why I'm not sleeping if you tell me your problem first.LOL.

When dealing with hp that the compressor is rated at it would serve you well to call the mfg.

Depending on how the compressor was made and the refrigerant and temps that the compressor was rated for...one could be confuse as to which numbers to go by.

Example...low temp back pressure compressor.-10 degree evaporator using r12 refrigerant.1hp=6000 btu/hr at 230 volt single phase.

Now take a high temp comp and the evaporator temp is 45 degree using r22 refrigerant at 230/1 and rated for 12000btus at 1hp.That a aka5512exd tecumseh compressor.

Then if you were to look it would show a tecumseh model aka5512exv at 1hp will give you 15000 btus at the same voltage and refrigerant.
• Member Posts: 1,380
Horsepower

Without having to go through a ton (no pun intended) of calculations, the 1 hp = 1 ton rule of thumb will put you very close for high temperature (cooling) refrigeration applications.

As Don mentioned, in order to actually calculate the relationship for a particular system operating as a specific set of conditions, you would need to plot the system on a pressure-enthalpy diagram, determine the theoretical horsepower per ton and the system capacity. Once this is done, you can obtain the actual conversion factor at that point in time.
• Member Posts: 2,144
H.P.to tons

Hi servicewiz ,the OLD rule of thumb was,for AC it was 12,000 btu's per ton { 5 tons =5 hp =60,000 btu};for a medium temp refrgerator it was 9000 btu's per hp and for a freezer @ 0* it was 6000 btu's per hp .But now for refrigeration, if you know the btu's of a walkin,you MUST look up the RATED btu's of the comp and use that comp which matches the btu's at the evap temp of the system you are working on.A 2hp r22 med temp comp may produce only9000 btu's , so get used to looking up the info.Or relie on a knowledgeable counter person.
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