question on chiller

[iczboi]

Hi everyone,

I have 2 questions about chiller:

1. Is the power consumption of chilling the water from 28 to 26 the same as from 27 to 25?

2. If it takes 30 minutes to heat up from 26 back to 28, does it takes the same time for it to heat up from 25 to 27?

Thanks alot for the help rendered.

[klim]

Logically it is different, although both the parameter is diff by 2 degrees but one is chill to 26 and the other is 25. The 1 degree coldness is a lot

[n3xt]

From what I know, the rate of temperature change increase with the difference in temperature. So for an ambient temperature of say 30, the tank will heat up faster from 25 to 27 faster than 26 to 28.

[iczboi]

So that would translate to increase in power consumption.

[QwekSengKiang]

Your chiller will take more effort to cool the temperature from 27 to 25 degree, thereby consuming more power as compared to 28 to 26 degree. The same chiller will kick in more often for the case of cooling to a lower temperature.

Assuming both tanks of same setup and room condition and the heat up time of 30 mins from 26 back to 28 degree. The likelyhood is that it will take lesser time for it to heat up from 25 to 27 degree.

During a hot season, it will take a shorter time for the temperature to heat up and a longer time for the tank to cool down and the opposite applies during colder seasons.

[skyjuice123]

Assuming that one has a 100% insulated tank with no pumps and lights etc i.e. no heat can get out or into the tank. The chiller will get the same energy out of the tank irrespective of the tank's temperature because both scenarios have the same temperature differences of 2C. In the real world, the tanks are exposed to the ambient air and therefore, gains heat from its surroundings, The lower the tank temperature, the more heat gain from the surroundings and hence, the harder the chiller will have to work. The principle is about the same as our room air conditioning system.

Depending on the tank sizes, the heat gain from the exposed glasses can be responsible for 15-50% of the chiller load; therefore, by insulating the tanks, one can save up to 35% of this energy depending on the size of the tank. Raising the tank temperature will save energy too. For every 1C raise, one should save at least 5-6% (assuming same as room airconditioning) of the heat gain through the glasses.

http://skyjuiceiswater.blogspot.sg/2012/12/insulation-for-reef-tanks.html