Difference Between Refrigerator and A/C compressors

Hello.

I noticed that refrigerator compressors are leaps and bounds more expensive per watt than air conditioner compressors here, but, I am also curious, what is the difference?

Could it be that refrigerator compressors can operate safely at low freezing temperatures that typical air conditioner compressors cannot?

Also, does anyone know what the minimum temperature a 9,000 BTU standard A/C can safely operate at is?

Thank you for your time.

One more question I forgot to ask. Are refrigerator compressors built better to last longer with continuous use?

I really want to know the answers to these questions.

Hi Kompulsa

the cost you state of refrigerator compressors being more expensive is surprising

a compressor/pot is a pot in my eyes

maybe I am missing something, but struggle to see what

I presume its just suppliers and their mark up on domestic pots

An a/c unit will only operate at chilled temps, normally locked out to plus 10*c or higher

Setting a lower temperature than is required say between plus 18*c & 22*c is not required

The unit will reach these temps dependant upon abient temp and room temp and heat load

And running within design criteria of full charge of refrigerant, clean coils/air flow/good working order compressor

R's chillerman

Quote:

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Originally Posted by chillerman2006

Hi Kompulsa

the cost you state of refrigerator compressors being more expensive is surprising

a compressor/pot is a pot in my eyes

maybe I am missing something, but struggle to see what

I presume its just suppliers and their mark up on domestic pots

An a/c unit will only operate at chilled temps, normally locked out to plus 10*c or higher

Setting a lower temperature than is required say between plus 18*c & 22*c is not required

The unit will reach these temps dependant upon abient temp and room temp and heat load

And running within design criteria of full charge of refrigerant, clean coils/air flow/good working order compressor

R's chillerman

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When you say "locked out", do you mean that it shuts itself off when the evaporator temperature drops below 10 C?

I still wish I could find out why the cost of the refrigerator ones is so much more if it isn't determined by the ability of the fridge ones to handle colder temperatures.

Quote:

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Originally Posted by Kompulsa

When you say "locked out", do you mean that it shuts itself off when the evaporator temperature drops below 10 C?

I still wish I could find out why the cost of the refrigerator ones is so much more if it isn't determined by the ability of the fridge ones to handle colder temperatures.

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Hi Kompulsa

By ''locked out'' I mean the manufacturer has pre set the adjustable parameters that you are able to use

All compressors differ in price, mate

If a freezer and an a/c unit used the same compressor they would be the same price

Its a bit like saying why does a bitzer screw compressor cost about £10,000GBP and a copeland scroll a fraction of that

R's chillerman

Quote:

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Originally Posted by Kompulsa

Hello.

I noticed that refrigerator compressors are leaps and bounds more expensive per watt than air conditioner compressors here, but, I am also curious, what is the difference?

Could it be that refrigerator compressors can operate safely at low freezing temperatures that typical air conditioner compressors cannot?

Also, does anyone know what the minimum temperature a 9,000 BTU standard A/C can safely operate at is?

Thank you for your time.

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Compressors are manufactured to handle different pressures, i.e. Low Back pressure, Medium Back pressure and High Back pressure.

If you are using a high pressure refrigerant, you wouldn't select a LBP compressor, and vice versa.

Most high pressure refrigerants aren't suitable for low temperature applications.

Are you able to post the 9000btu compressor details?

a 9k btu compressor at 20c is a lot smaller than a 9k at zero. However many have used air con condensing units for refrigeration systems with great success.

Quote:

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Originally Posted by frank

Compressors are manufactured to handle different pressures, i.e. Low Back pressure, Medium Back pressure and High Back pressure.

If you are using a high pressure refrigerant, you wouldn't select a LBP compressor, and vice versa.

Most high pressure refrigerants aren't suitable for low temperature applications.

Are you able to post the 9000btu compressor details?

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I haven't obtained it as yet. I will in 3 weeks.

I didn't fully understand the relationship between what you mentioned about pressure and the reason why the fridge compressors are more expensive.

I admit that I am still learning and experimenting with these things. The compressor isn't to replace one in an existing air conditioner, but I love building these things and learning more about them.

I plan to try projects involving especially the refrigeration of water, not particularly for food, but room cooling as well. Also water heating as well.

I want to be sure of what I cannot do with the 9,000 BTU and the fridge compressor. the fridge compressor I have in mind is only 1/3 HP which is far less powerful than the 9,000 BTU but is a little more expensive.

Here is one of the most important questions and determining factors of which I would choose first: Can I at least safely freeze water with the 9,000 BTU A/C compressor? If so, then great because it is what I want primarily.