Energyguide Labels Explanation Needed

sub3marathonmansub3marathonman Solar Expert Posts: 300 ✭✭✭
This is a basic question, but I can't find any answers after doing research.

For the Energyguide Labels on appliances, how are the numbers calculated? For example, for a refrigerator is it the amount of energy it would use just standing for a year, or is it the amount of energy it would use with a certain amount of usage every day? The same thing for a water heater. Is the label calculated on keeping a certain number of gallons at a certain temperature for a year, or is it calculated with a theoretical usage model?

As a follow-up, is there any method for determining the rate of energy loss from a water heater at a given standard temperature?


  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Energyguide Labels Explanation Needed

    Good question.

    The only answer I can give is that the numbers are relative anyway, and should only be used to compare one unit to another. In theory, they're all tested the same way. I wouldn't count on the numbers being "real world" results.

    The Gov't says the yearly electrical use figure is based on "typical" use, whatever that may be.
  • BB.BB. Super Moderators, Administrators Posts: 32,924 admin
    Re: Energyguide Labels Explanation Needed

    For refrigerators, one of the vendors (off grid) listed their energy star and 70F ratings (plus a few other temperatures too?)... As I remember it looked like the 90F vendor test had the same numbers as the Energy Star test rating (same model all for all tests).

    I don't think the Energy Star ratings include "other things"--like if you make a lot of ice every day--Measure your fridge daily kWH usage and see it go up when it is making ice. I assume it would not include place room temperature goods in the fridge/freezer every day either.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Energyguide Labels Explanation Needed

    Also note that a fridge or freezer (or any other appliance) only gets the Energy Star label if the extra cost of the additional efficiency can be paid back within 3 years. I find that weird and wrong, because you could come across the most efficient fridge the world has ever seen, but if the additional cost can't be repaid by energy savings within 3 years, it won't get the Energy Star approval!
    Also, some very heavy users, such as fridges with built in ice makers, real energy hogs compared to those without that feature, can end up with the Energy Star rating if they use somewhat less than other fridges with the same features.
    So in my opinion, Energy Star needs a real, serious, major overhaul!
  • petertearaipetertearai Solar Expert Posts: 471 ✭✭✭✭
    Re: Energyguide Labels Explanation Needed

    Hi I bought a small fridge freezer With a energy star rating of 5. This was under what was called the old rating system Under the new star rating it is 2.5 stars. The important number for me was the kwhours per year,in this it was 339kw per year This equates to .9 kw per day. Temps inside the house range between 18deg C and 28deg C. I have had it plugged into a kwh meter and It does indeed use around .9kw on the 1st day of the weekend and .8 on the next day accounting for the initial running to get down to temp on the first day.So in short energy rating helped me buy the fridge freezer.
    2225 wattts pv . Outback 2kw  fxr pure sine inverter . fm80 charge controller . Mate 3. victron battery monitor . 24 volts  in 2 volt Shoto lead carbon extreme batterys. off grid  holiday home 
  • russruss Solar Expert Posts: 593 ✭✭
    Re: Energyguide Labels Explanation Needed

    Unless a lot of money is spent to support an independent testing organization you won't get much better than energy star. Expense with no real return.

    It relies upon the manufacturers being honest with no real penalties for when they get caught lying. If there was such a penalty such as jail time for the CEO for misrepresenting energy consumption the problem would be solved. Penalties to the company are meaningless.

    If you see the testing protocol (on the energy star web site) you can see the test conditions.
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