power rating in the nameplate
power rating in the nameplate
(OP)
Does the power rating at the back or nameplate of an airconditioning unit if converted to tons of refrigeration (TOR) can cool a space of the same TOR?
For example, if the nameplate has a power rating of say 3.517 kW and if converted to TOR is equivalent to 1 tons. Does this mean that it can extract 1 ton of heat in the space?
If so, are all ac units 100% efficient?
For example, if the nameplate has a power rating of say 3.517 kW and if converted to TOR is equivalent to 1 tons. Does this mean that it can extract 1 ton of heat in the space?
If so, are all ac units 100% efficient?





RE: power rating in the nameplate
RE: power rating in the nameplate
If both, then if I calculated a space heat load of about 1ton, what type of ac unit should I buy? I mean what nameplate rating should I choose?
RE: power rating in the nameplate
I assume you just talk about a 2 ton residential unit, then just use that capacity if your ambient design temperature is not much more than 90°F. Load calculation is more a good estimate when you don't know the users. In an office it is more predictable by the number of PCs, lights etc. In residential, one day my wife bakes cookies (cooling load), the other day not
RE: power rating in the nameplate
RE: power rating in the nameplate
AS far as name plate rating is concerned.... its the electrical power. which means the power required for the unit like a 60 W electrical bulb.
When an air conditioning unit is sized and rated lile 2 tons capacity or 5 tons.... this is the thermal power. Its not the electrical power. this means that this unit is capable of prducing 5*12000 of cooling every hour.
Basic principleas of physics are not wrong. Its not 100% efficient. If you see the cooling capacity (thermal power) of this machine ... and divide electrical power by it, You will get more than 1.
Normally DX type units have a range of about 1.8 to 2 kW / Tons. Which means for every ton electrical [power consumed is 1.8 to 2 kW. Now if we express the thermal power One ton also in kW which is 3.51 kW. the ratio becomes
1.8 (electrical power) / (3.51 Thermal Power)= 0.514
Dont mix the two powers... One of them is electrical, other is thermal
RE: power rating in the nameplate
<b>So, the question now is becoming clearer, if after calculating the space heat load as say for example 1 ton (thermal power) how much factor would you recommend so I could multiply it to the calculated thermal power so I could correctly size my ac unit? Or are there any standards where I could used to properly choose an ac unit after calculating the space heat load?<b>
By the way, all reply are of big help to me...
Thank you so much.
RE: power rating in the nameplate
RE: power rating in the nameplate
Regards,
EEJaime
RE: power rating in the nameplate
RE: power rating in the nameplate
RE: power rating in the nameplate
There is so called the coefficient of performance or COP (sometimes CP), of a AC or heat pump is the ratio of the change in heat at the "output" (the heat reservoir of interest) to the supplied work.
COPcooling = deltaQcold/deltaW
deltaQcold - is the heat moved from the cold reservoir (to the hot reservoir;
deltaW - is the work consumed by AC.
COP (or CP) also can be shown in a nameplate.
Regards,
curtis