Are you considering installing a heat pump? A large number of Samsø’s homes are heated using heat pumps, but why are they good to have and how do they work? Ole Hemmingsen is a blacksmith and plumber on Samsø, and he explains the basic workings of heat pumps.
What is a heat pump?
It’s a device that converts heat from the ground and pumps it throughout your house using either air or water. There are three types of heat pumps: geothermal heat, air-to-air, and air-to-water.
How do heat pumps work?
Using an evaporator, the heat pump absorbs energy from the environment, which causes the refrigerant to boil and evaporate. The steam is then compressed inside the compressor, the pressure increases and the temperature rises.
The refrigerant then releases its heat in the condenser, where it cools and turns back into a liquid that flows through the thermo-valve, where the process starts all over again. It’s in the condenser that the heat from the refrigerant is transferred to the home’s heat distribution system, either in the form of a water-conductor central heating system, or as heated air that can be blown into the house.
Why is a heat pump preferable to a fossil-fuel based heating source?
A heat pump has limited carbon dioxide (CO2) emissions because it gets its electricity from a fossil-free energy source. On top of this, you get 4-5 times the amount of energy out of a heat pump than that which goes into it, depending on which power source the heat pump is connected to. If it gets its energy from an old oil furnace, there may be negative energy utilization.
There are three kinds of heat pumps: How do you know which one to choose?
If you want to install a heat pump in a house where there is only electric heating, the air-to-air heat pump is ideal. This is especially true for holiday homes. If instead you have a central heating system with radiators, it’s perhaps better with a water-conducting air-to-water heat pump system, combined with geothermal heating. The latter is most commonly used, but requires a reasonably large area outside where hoses can be buried. Air-to-water is smart if you want heated floors, because you make optimal use of the surplus heat.
Why are there so many heat pumps particularly on Samsø?
There have been some good plumbers on the island who have understood the value of their products, given the increased attention paid to the negative impact of CO2 emissions on our environment. Eighty-percent of the year-round homes on Samsø that are not connected to district heating use heat pumps, and we have less than 200 oil furnaces left on the island.
Worth knowing about heat pumps:
Brands: There are myriad of brands produced in Denmark and abroad. Vølund, Boss, Danfoss and Panasonic all produce heat pumps, but which brand you choose depends on your needs and budget. You can buy heat pumps from your local plumbing installer.
Price estimates: Air-to-air pumps cost between 14-18,000 Danish kroner. (€1,900-2,400); air-to-water approximately 100,000 kroner (€13,500), while geothermal heat pumps costs about 125,000 kroner (€16,800). All prices include installation, which takes about 2-3 days depending on which solution you choose. Always remember to take advantage of the Danish tradesman deduction.
Savings: Compared to oil furnaces, you will approximately halve your annual heating costs. Furthermore, if your consumption is over 4,000 kilowatts, you can save around 62 øre (8 eurocents) per kilowatt through the public energy savings subsidy.
Maintenance: A heat pump should be inspected regularly and replaced every 10-15 years in order to stay in step with technological advances. Heat pumps are becoming more and more effective every year, and it is worth replacing them to achieve savings that newer models offer. Many also supplement their heat pump with a wood pellet stove, for which you can also receive subsidies.
Read more about heat pumps and their possibilities at www.energitjenesten.dk