Supplemental home heating for the cost of running a light bulb
A recently developed home heating system, the attic Heat Harvester, uses free solar heated attic air to achieve remarkable heating system efficiency. Having a supplementary heating system that uses free solar heated attic air reduces the use of other heating systems to reduce heating costs.
Conventional fossil fuelled central heating systems and furnaces achieve efficiencies of 0.25 to 1,
and are dependant on the home heating system type and age. Heat pump based systems can achieve efficiencies of 3.
Attic Heat Harvester heating system efficiency is proportional to attic - room temperature difference and air flow, and inversely proportional to fan power consumption.
The chart shows that even at modest attic - room temperature differences system heating efficiency massively exceeds that of all other heating systems.
Typically the Attic Heat Harvester System heating efficiency is 5 to 50 times higher than other heating systems because it uses free solar energy and minimum electrical energy to run a fan.
At a typical air flow rate of 1000cmh achieved by an efficient 80 watt fan, and a temperature difference of 5°C, heating system efficiency is 23. At a temperature difference of 10°C the heating system efficiency is 45.
If the fan runs for 5 hours at an average temperature difference of 5°C, 9kWh of free solar heat is transferred. Currently UK electricity costs, on average, £0.14 per kWh, the total cost of the heat is 5 x 0.14 x 80/1000 = £0.056, the heat cost per kWh is £0.056/9 = £0.006.
The effectiveness of an attic heat harvesting system and how much you can reduce heating cost is dependant on your homes characteristics and location.
Reduce Heating Costs by Utilising Free Solar Heat
Attic heat harvesting is incredibly efficient because it uses: a) free heat created by solar energy that heats attic air to relatively high temperatures, and b) the lowest electrical energy of any active home heating system.