Underfloor Heating
How much does Underfloor heating cost to run is obviously one of the most common questions & the short answer is that it can vary quite a bit. The size & design of your home, the temperature you want to achieve & the choice of your heat source all play a major role. For instance using a heat pump connusing off-peak or standard rate power will all affect the heating costs.
Whilst here in Australia, insulation levels may not be as good as many European countries where floor heating is one of the most popular forms of heating, this is usually compensated for by the fact that our external winter temperatures are in most cases, considerably higher. If you want to reduce your carbon footprint & keep heating & cooling costs to a minimum, consideration should always be given to a good solar passive design & the highest levels of insulation that are practical within your budget. Increasing ceiling insulation & even double glazing the windows will usually always pay for themselves over the long term. Many people are also now adding PV ‘solar power' to their home design, again to reduce power bills.
Our best advice on this subject if using under floor heating as your main winter heating system would be to carefully consider using off peak power where available as this can often result in savings of close to 50% compared with standard tariffs.
The typical energy required to heat a typical brick veneer style house with typical insulation is about 100w per square metre. If the house is poorly insulated this can increase to 120w but if the house is well insulated this can be reduced to 60w per square metre. We have examples below comparing electric element heating to hydronic based heating we have used heat pump to make the comparison here as they both use electricity as the energy source.
Examples:
Typical Home is 150sqm of heatable area.
With Element Elecric based on the average home size of 150sqm the energy required at 100w per sq/m would be 15000w to heat the floor. This would run at an average of 4-6 hours per day to maintain the floor temperature. At the current standard tariff price of around 18 cents per Kwh, the total running cost would be worked out the following way.
Heat requirement = 15Kw x by the $0.18 per Kwh. So the 15x0.18= $2.70 per hour then multiply this by 5 hours per day.
Per day cost is $13.50 per day. So then you require the heating for at least 3 months of the year. $13.50 x 90 days = $1215.00. It would be wise to run this type of system on off peak power tariff so it only runs overnight. This would reduce the cost as power at night is about $0.11 per Kwh. This would bring it down to $742.50
With Heat Pump Elecric based on the average home size of 150sqm the energy required at 100w per sq/m would be 15000w to heat the floor. This would run at an average of 4-6 hours per day to maintain the floor temperature. As a heat pump generates the heat far more efficiently the cost savings are very significant. The heat pump will generate 4watts of heat for every 1watt of electricity input. This equates to a minimum 75% saving in power. At the current standard tariff price of around 18 cents per Kwh, the total running cost would be worked out the following way.
Heat requirement = 15Kw but the heat pump can produce this heat energy 75% more efficiently than the electric element so therefore the electrical input is only 3.75Kw.
Then the electrical input of 3.75Kw is multiplied by 5 hours. So the 3.75x0.18= $0.68c per hour then multiply this by 5 hours per day.
So the x18= $0.68 per hour then multiply this by 5 hours per day.
Per day cost is $3.38 per day. So then you require the heating for at least 3 months of the year. $3.38 x 90 days = $303.75. You could then run the system on off peak power tariff so it only runs overnight. This would reduce the cost as power at night is about $0.11 per Kwh. This would bring it down to $185.63
*These calculations are for illustration purposes & as stated above, it should be noted that the running costs will vary from state to state & are dependent on the size & design of home, the desired temperature & current electricity prices.