air conditioner vs refrigerator compressor

[tinsnano]

Dear all,

I am building ice maker. I have passed many of the challenges I faced, but now is another challenge i am facing. And i will ask you if the solution that i am thinking might work

the problem is:- i cant get compressor(hermetic piston type) with enough HP like 3-5Hp for ice making but those type of compressor used for air conditioning that look like cylinder are available for example 14000btu/hr when i convert this to hp it is about 5Hp. 1/2 hp compressor for refrigeration is available for my ice maker so to raise my ice production rate i am planning to build cooler/chiller with the air conditioner 5hp compressor and chill the water and feed it to the ice maker

does this solution sound good?

 

[MintJulep]

Although BTU/hr and Hp are both units of power, as used when talking about compressors BTU/hr is exclusively cooling capacity and Hp is compressor motor input.

They are not directly interchangeable to compare compressors.

 

[tinsnano]

ok thankyou i got your point. but can i use air conditioner compressor for cooling/chilling water which then i feed to the ice maker and hence enhance production rate?

 

[IRstuff]

As MJ explained, an AC compressor rating is NOT the cooling capacity of the AC system. A typical compressor for a 1-ton AC is, itself, only about a 1-hp compressor, but much depends on the exact design and operating point of the system as a whole.

TTFN (ta ta for now)
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[tinsnano]

so is there any limitation building water cooler with AC compressor? because AC compressor is more available to me

 

[MintJulep]

Provided that the suction and discharge conditions are within the limits established by the manufacturer the compressor will not know or care what it is cooling.

 

[berkshire]

Here is a reply to a similar post on the Refrigeration engineer forum. Unfortunately not one of the forums here.
You are looking for the difference between high back pressure and low back pressure compressors.


Low temp compressors definitely cannot be used with medium or high temperature evaporators because they will overload. They have a larger displacement to compensate for the lower suction pressure. That is why many low temp systems include a crankcase pressure regulator for warm box pulldowns or when recovering from defrosts. On the other hand, a compressor designed for high back pressure will be under loaded when used on low temp systems. This can result in motor overheating on a hermetic or refrigerant cooled semi-hermetic compressor. The superheat must be kept to a minimum in the suction gas. I have had very good luck with a few Copelaweld CR model compressors used on freezers. Although, they are not recommended for such applications, my experience has been very good. Another consideration is that the compressor will not have the capacity when under loaded. For instance, a three HP air-conditioning compressor will not pump the same volume as a three HP freezer compressor.


B.E.

You are judged not by what you know, but by what you can do.

 

[EnergyProfessional]

Typically you work with a manufacturer rep or study their literature to learn what conditions the equipment can operate in. For example high ambient temperature and freezer application is different from low ambient and building HVAC.
The topic of refrigeration huge. In a nutsheell COP and compressor power depend on:
- refrigerant
- temperatures on condenser and evaporator
- compressor type
- heat exchanger UA (i.e. coil sizes)
- lubrication system and oil return
- for each of the above multiple variatiosn and options of all the misc. equipment required.

You typically specify a refrigeration equipment and it comes with the proper motor and compressor. The only reason to worry is because you need to size electrical system and for energy consumption. Other than that we only care about refrigeration performance (i.e. tonnage)

 

[itsmoked]

tinsnano; Consider yourself creeping along a rocky shoreline with high surf.

Setting up a reliable refrigeration system is filled with pitfalls. Professionals screw it up frequently. Whatever you cobble together is going to have lots of issues. Some will will be small, lots will be energy wasters, and some may be immediate show-stoppers. Most will just be slow nefarious show stoppers guaranteed to hit you at the worst time, which is always when the highest loads are demanded or the most food is at risk.

Do not bother attempting to use A/C equipment to do refrigeration jobs you will be wasting a bunch of time and all your money.

You want ice for what?
What size ice?
How much do you need made in 24 hours?
What electrical power do you have available?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[tinsnano]

Dear itsmoked

look i dont want the A/C compressor to make ice directly. what i want is let the A/C compressor chill a water say 5 degree celesius and another freezer compressor will make this water to ice

i want the ice for drinking
ice size 4-5cm and diam of 1cm

80-120 kg/24hr


my compressor
freezer compressor 0.5hp
A/C compressor about 14000btu/hr
electric supply is up to 3kw is available

 

[IRstuff]

Again, the 14000 BTU/hr rating is for the A/C, not the compressor.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[tinsnano]

ok 14ton is for A/C, so does the system seems feasible?

 

[EnergyProfessional]

You need to hire someone to design this. And you can't just build your own refrigerant system without in-depth knowledge. Manufacturers have this all figured out, you can't just solder something in your garage and think this is cheaper and better. You also need EPa certification to handle refrigerant, electrical license....

 

[chicopee]

What's the point of spending all that time to build a machine when it is already available for purchase. I realize that building things is fun but foolish time spent is wasting money.

 

[tinsnano]

cause it seems purchasing it is expensive than building it at least in may country

 

[DrRTU]

To lower the approach temp to your freezer, find a used food grade 2 ton aircooled chiller. If you can’t find a food grade unit, use a chiller from the injection molding industry and run PG solution to a heat exchanger you build or a small brazed plate & frame unit. The evap/barrel design will be just as complex as the refrigeration. If your design is not correct, you will freeze the feed water evap. Ebay?