Conversion

Very roughly, each chiller will use about 300 kw, or 1200 kw total. A real calculation would depend on the refrigerant and its evaporating and condensing temperatures. Even better for your instance is to get the electrical ratings from the chiller supplier. They should have a data sheet with motor size (hp or kw), voltage, and amperage.

thanks! our supplier is from Belgium. We are oly dealing with our Consultant frm Belgium too. They informed us of Cooling KW to prepare the power rquirements.

The electrical load will depend upon the efficiency of the cooling system. Typically 1kW elec power gives 3kW of cooling.

The only way to really know is to ask the manufacturer. Then size the cables to get the permissible voltage drop as specified by the local supply authority.

thanks. our supplier is from belgium. our consultant sent us this info and they are in belgium too. we are only preparing fo power rquirement. one manufacturer here locally told me it is 3.5 kw cooling to 1 kw power. but the conversion sent to us by our consultant dont tally with this conversion factor. 1300 kw cooling he computed to 540 kw electrical power. i think 1 kw to 3 is nearer x effeciency.

As a rule of thumb, and considering that you are using pumps etc ,

your best guess will be half the coolink capacity: 1kw cooling will definitely be more confortable with 0.5kW electric. The efficiencies and auxiliaries will prove that it could be nearer for your comfort.

At best, the manufacturer will have to give you the required electric power required per chiller and the auxiliaries... don't forget.

thanks sir, good information.

i dont knew the manufacturer yet. we are in Saudi and it's our consultant which in contact withthe manufacturer. my job is to prepare for power supply. i only want to knew where he got this 540 kw electrical power required for his chiller with 1300 kw capacity. i also wanted to know if their is a standard conversion factor for cooling KW to electrical power KW,

There is no standard conversion ratio for this.

It all depends on the efficiency of the whole chiller system including pumps and Fans etc. Every manufacturer will be slightly different.

I have already given you a good rule of thumb to be on the safe side. It also matches the #6 (instead of 1.5kW per ton of refrigeration, I would take 1.8 kW which is equivalent to dividing the cooling kW by 2 to get the electric kW).

Still I insist: if you want to be very accurate you must check with the manufacturer. The rule to divide by 2 will give you the best security to avoid under estimating the requirement and is the most safe.

Good luck

(by the way, 1TR = 12,000 BTU/h = 12,667 kJ/h = 3.518 kW cooling power which I recommend to divide by 2 = 1.76 kW electric power if you have no other info from the manufacturer of the package and you might need to add circulating pumps etc..?)

Dear Mr. LAA,

Now I got it. Our consultant use the 2 in conversion.

Thanks a lot.

You are welcome.

You need to find out what is the COP ( Coefficient of Performance ) of the chiller unit.

Typical figures range from 2 - 3.5 and depending on the type of chiller unit ( vane, centrifugal, reciprocating, absorption).

Once you have the typical COP, take the chiller capacity ( kw) and divide by the COP and that gives you the absorbed power in electrical kw into the chiller compressor.

Hope that helps

Thanks Sir, Now it is more clearer to me. Most probably we will use the vane type. We dont received yet the Chiller manual hence we are still negotiating with our prospective supplier.