Water Heaters / Geysers Power Consumption



We have seen the BEE star ratings for water heaters and geysers. But the question remains: how much power does a water heater consume? Let us explore this question.

There is no clear-cut calculation for determining the water heater power consumption because the consumption depends on multiple factors, like the water heater’s capacity, the Standing Loss factor, and the appliance’s star rating. Other factors include the average usage time and the number of people in the house using the geyser.

The General Formula

The standard formula for calculating water heater power consumption is as follows.

Total Power consumption = Rated capacity of the water heater X Total operating hours.

Therefore, if you have a 3Kw geyser at home and use it for two hours daily, the daily power consumption equals 3Kw x 2 hours = 6Kwh. One unit of electricity consumed equals 1Kwh. Therefore, your water heater consumes six units of electricity per day.

Accordingly, you can calculate your monthly and annual consumption. However, these calculations are based on ideal conditions and give reasonably accurate readings. Note that we have not accounted for the standing loss factor. Ideally, we must add the Standing Loss figure to the power consumption to get more accurate results.

Factors that determine energy consumption

The calculation appears simple, but various factors determine the water heater’s power consumption.

  • If more people use the geyser, it functions for more time. Hence, power consumption is higher.
  • Similarly, if the water is cold, especially in the monsoon and winter, the water heater takes more time to heat the water. Therefore, power consumption is more.
  • An oversized geyser consumes more power because it will take more time to heat the water. Secondly, you will not consume the entire water and leave it in the geyser. Finally, the standing loss concept will come into the picture.
  • It is better to use 5-star water heaters because they can retain heat for extended periods compared to 3-star and 4-star geysers.

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