We have a number of ice machines on our project that are Energy Star certified. The manufacturer will only provide us power usage in the form of kWh/100 lbs of ice (which is the Energy Star criteria). From the spec sheet, we know that the maximum output is 390 lbs. over a 24 hour period. Is it acceptable to use this information, and calculate the watts by using the formula:
P(w) = 1000 x E(kWh) / t(hr)
For example, the machine uses 5.79kWh/100 lbs of ice. Multiply that by 390 lbs per 24 hours equals 22.581kWh per day. Using the formula above, this would translate to 952.125 watts.
Can we use this as our rated power given that the manufacturer will only provide power use in kWh/100 lbs ice?
Michelle Rosenberger
PartnerArchEcology
522 thumbs up
March 12, 2013 - 4:29 pm
Hi William,
We also often have difficulty getting the rated power of pieces of equipment. It's hard to get from manufacturers and finding a nameplate is unrealistic. We make our calculations with Volts x Amps to get kWh rated power. The ice machines I have seen cut sheets for do supply that info. We have been doing this consistently on our projects with no challenges.
Suzanne Painter-Supplee, LEED AP+ID&C
PrincipalSEESolutions LLC
126 thumbs up
April 19, 2013 - 10:25 pm
kWh per 100 lbs. of ice is one of the most effective way to determine how much ice will be used. Same goes for warewashing in determining dishwasher run time. A kitchen designer will design for a meal count, and it is very easy to determine how much ice is needed to feed X number of people. A fast food figure is considered .9 lbs./guest; a hotel, 3-5 lbs./room, 10 lbs./patient bed., 1.7 lbs. sit down restaurant guest, etc. A salad bar using ice uses 30 lbs./sq. foot. So the really easy part is to factor the guests, and where else ice is used. A cold plate on a beverage dispenser is capacity of dispenser plus 40%. I love ice because it is very simple to figure out how much you need. Something else to consider is that numbers are based on 90 degree air, 70 degree water temperature, so climate has a big impact. If you want a chart of usage per guest depending on function, contact me and I will give it to you.