Space Heaters

Which space heater consumes the least electricity?

Heating Trends, last updated on November 21, 2022

When colder days come, many are looking for heaters to heat their space. Consumption also needs to be taken into account if we want to avoid a large electricity bill.


Which space heater consumes the least electricity?

In the offer of cheaper heating devices, heaters, convector radiators, oil radiators and quartz heaters can most often be found. The question is - which heater will heat us the best, while consuming the least electricity? Although one can often read texts and marketing tricks on the topic of more energy efficient and less efficient convector heaters, the answer is very simple and lies in the laws of physics. Speaking of electric heaters that use heaters for heating, all heaters will give exactly the same amount of heat. The efficiency of electricity when converting into thermal energy is almost 100%, and the heater will consume exactly as many kilowatts as declared. This rule does not apply to inverter air conditioners (heat pumps) which can give 3, 4 or even over 5 kW of heat energy for the consumed 1 kW of power. Heating with air conditioning is the most cost-effective way of heating with electricity, but it also has its drawbacks.

How much electricity does the heater actually consume?

You can easily calculate the real consumption of the heater by using a wattmeter, which can be purchased in the centers for a hundred kuna. Sometimes the heater has minor deviations and consumes slightly less or slightly more than the declared power. Also, you can measure consumption by turning off all consumers and turning on only the heater for an hour and recording the state of the meter before and after the measurement. Note that devices in stand-by mode (turned off the TV, refrigerator, wifi router) also consume some energy, but this method will give you an deductive result of consumption. Suppose that the heater you purchased consumes exactly as much as it says on the declaration - 2000 W (2 kW). Whether your heater is a heater, convector, oil radiator, thermal storage stove - it will transfer the same amount of heat energy to the space.

2 kW * 1 h = 2 kWh

If you leave a 2 kW heater running at full intensity continuously for an hour, it will consume exactly 2 kWh. Let's assume the price of electricity for households with a two-tariff meter during the higher daily tariff is about $0.16. With a simple calculation, we come to the conclusion that our heater consumed 2 kWh in an hour, which we will pay $0.32. There is also a fixed fee for the supply point on the electricity bill, but it does not depend on the monthly consumption. If you turn on the heater between 9 pm and 7 am, you will use a lower daily tariff and pay about half a kilowatt hour. But at night, while we sleep, we usually do not need heating.

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Heat accumulation during lower tariffs

The only way to save on electricity used for heating with traditional heaters is to accumulate heat energy at night during the lower tariff and release heat during the day when we actually need heating. The 3.5 kW heat storage furnace will still consume the same as any other heater of the same power, but it will consume "cheaper electricity" at night, so the monthly bill will be much lower compared to heaters that heat during the day.

Insulation - energy savings

It is important to know that the most common reasons for high heating costs are poor thermal insulation of the space (non-existent or dilapidated thermal facade), poor, dilapidated windows and doors and poor or non-existent insulation of roofs or blankets of upper floors. By investing in quality insulation of the building, you reduce heat losses by 40% - 60%. An uninsulated or poorly insulated building loses large amounts of energy, so it is necessary to invest large amounts of energy in order to heat the space, and by turning off the heating, the temperature in the room drops very quickly. With large losses, each method of heating is expensive.

Feeling of warmth

Although all heaters will transfer the same amount of heat energy to the space for the same electricity consumption, the heat sensation may not be the same. Thus, the oil radiator will gradually heat the air and the objects around it with radiation, while, for example, the heater will quickly fill the room with warm air. The quartz heater will instantly heat people and objects in its vicinity with infrared radiation, but it will not heat the air either. Also, by deploying lower power heaters to more strategic locations (under windows, on the north or exterior walls) it will give a more comfortable and even feeling of warmth.