Space heaters are portable electric devices used for heating up a single room or an area of the house. Convection space heaters heat up a room by heating up the air, most common convection space heaters will use around 1500 watts. Click calculate to find the energy consumption of a space heater using 1500 Watts for 5 hours a day @ $0.10 per kWh. Hours Used Per Day: Enter how many hours the device is being used on average per day, if the power consumption is lower than 1 hour per day enter as a decimal. (For example: 30 minutes per day is 0.5) Power Use (Watts): Enter the average power consumption of the device in watts. Price (kWh): Enter the cost you are paying on average per kilowatt hour, our caculators use the default value of 0.10 or 10 cents. To find an exact price check your electricity bill or take a look at Global Electricity Prices. Space heaters can be expensive to run and are generally less efficient than central furnace heating, however if you are only in a single room of the house during winter and do not want to heat up the entire home than a space heater can cost less to operate. You can lower the temperature of the entire house and set up a space heater in a room you are in, if you have good insulation and can retain heat in a single room this would save you money. There are some models of space heaters that are more environmentally friendly and use less energy, they may use as little as 400-500 watts compared to regular convection heaters. Space heaters can be dangerous if they are not carefully monitored, always read the manual of your space heater and make sure you are using it properly. > Suggest Corrections 12 This energy efficiency calculator is a simple tool for calculating the ratio of useful energy output to the energy input. You can use it for determining the proportions of heat energy, electric power, mechanical work, or even chemical energy. Continue reading to learn how to calculate efficiency, and discover the real-life applications of the efficiency formula.
The efficiency calculator is simple to use:
Efficiency is defined as the ratio of energy output to energy input. Every time that you supply energy or heat to a machine (for example, to a car engine), a certain part of this energy is wasted, and only some is converted to output in the form of actual work. The more efficient the machine, the greater output it produces for a given input. A special type of efficiency is the Carnot efficency. It is defined as the efficiency of the Carnot engine, which is an ideal engine that maximizes the energy output.
In order to calculate efficiency, you need to apply the following formula: η=Eout/Ein⋅100%η = E_\text{out} / E_\text{in} \cdot 100\%η=Eout/Ein⋅100% where:
Any efficiency calculated from real-world values will be between 0% and 100%.
The fundamental law of energy conservation states that you cannot create energy. Therefore, the efficiency of any machine can never exceed 100%. Nevertheless, you will probably come across articles saying that LED lights or heat pumps can have an efficiency of 300% or more. How is it possible? The apparent efficiency of 300% results from the definition of efficiency that we use. The electrical power supplied to LED lights might be actually lower than the output, but it doesn't mean that energy was created in the process. It merely means that the lights have received some heat energy from the surroundings and converted it into the output energy. As we aren't able to measure this additional input, the apparent efficiency rises above 100%.
Even though you probably don't notice it, we apply the definition of efficiency to other real-life phenomena. Some examples include:
To calculate the efficiency of a machine, proceed as follows:
Efficiency is a unitless quantity. It is the ratio of the energy output to the energy input; hence it has no units.
An efficiency of 60% means that only 60% of the energy supplied to the machine can be converted into useful work and the rest is lost.
No, a real machine can't have an efficiency of 100%. An efficiency of 100% means that there is no loss and the output energy (or work) of the machine is equal to input energy (or work). In real machines, there is always some loss of energy to overcome friction and air resistance. |