How does a geothermal heat pump work? Heat energy from the bedrock

Dimensioning of the heat pump is important

You must know the home's maximum power requirement to know what size of heat pump you need as it is dimensioned to cover the need for both heat and hot water. The heat pump must be able to cover 70 - 80% of the house's maximum power requirement, so it is usually dimensioned to meet 95% of the annual energy requirement. In addition to having the right dimension on the rock heat pump, it is also very important that the borehole has the right dimension and depth. This is to, with regard to operating costs and investment costs, get as efficient a system as possible.

Hire a certified installer and get quotes

The installer is the one who has to adapt the heat pump according to the house's energy needs and they have calculation programs to help them. It is also the installer who must make a savings calculation for the home and state what investments are required to achieve the promised savings. In order for the calculation to be as truthful as possible, the homeowner must provide as truthful information as possible about the energy use in the household.

Save energy

A geothermal heat pump has an energy saving of 50 - 80%. There are several factors that affect how much you can save. What can affect is, for example, where the house is located, how many people live in the house, how much hot water is consumed, what condition the house is in and if you have radiators or underfloor heating. Having the right dimension on the borehole and the ground source heat pump is also vital to get the most efficient system.

Compare the annual heat factor (SCOP)

SCOP (Seasonal Coefficient of Performance) shows the rock heat pump's annual heat factor. That is, the efficiency of the pump for an entire year. The annual heat factor for a heat pump is between 3 and almost up to 5, so for every kilowatt hour of electricity (kWh) that the heat pump consumes, you can get between 3 to almost 5 kilowatt hours of heat.

Do not confuse the annual heating factor (SCOP) with the heating factor COP (Coefficient of Performance) as this only shows the efficiency under certain conditions, for example a certain temperature of the water for the radiators or the floor heating.

Noise

If part of the basement space is to be used as a home, you should position the pump so that the sound from its fan does not interfere.

Take at least three quotes

You should take great care when choosing a salesperson installer and driller. Do not choose the first best but take in quotes from several companies to compare between. From the offer, it must be clear what is included in the price and what you must buy in order for the facility to be functional. Commissioning and adjustment of the heating system must be included in the offer. A savings calculation must also be included in the quote. In addition, the conditions for delivery, service, operation, payment and warranty must also be stated.

Contact your municipality in advance

Before you decide to install a geothermal heat pump, you should contact the environmental office or equivalent located in your municipality to get information about what permits are required. The energy and climate advisor in your municipality can give you impartial and free advice.

Upcoming requirements for ecodesign and energy labeling

At EU level, work is underway to develop ecodesign requirements and mandatory energy labeling for geothermal heat pumps. With ecodesign, it will be possible to set requirements for, among other things, sound level and energy efficiency. The proposal right now is that an energy class on the scale A ++ to G for heating and an energy class on the scale A to G for hot water will be displayed. Only heat pumps that meet these requirements will be sold when these requirements come into force, which will probably be in 2015–2016. The new requirements also make it easier for consumers to choose a heat pump.

Rock heat

We install and service geothermal heat pumps of various brands. Contact us and we will help with dimensioning and savings calculation.

Wikipedia information about Rock Heat

Bergvärme Bergvärme är ett tekniskt system för uppvärmning av byggnader. Lågvärdig energi, i form av kall vätska, hämtas från grundvattnet i berggrunden. En bergvärmepump höjer temperaturen till en nivå lämplig för byggnadens vattenburna uppvärmningsystem. För detta utför bergvärmepumpen ett mekaniskt arbete vars energi även tillförs byggnaden. En vanlig anläggning för uppvärmning av enfamiljshus består av ett, eller flera, 90–200 meter djupa hål som borras ner i berget. Ur berggrunden utvinner man sedan energi genom att en nedkyld vätska som passerar berget genom en ledning värms av grundvattnet i berget. Detta medför också då en viss nedkylning av detta grundvatten. Kollektorvätskan, som kallas köldbärare, cirkulerar genom berget och leds sedan till en förångare där köldbärarens temperatur kan vara väldigt låg, till och med under nollgradigt. I förångaren värmer vätskan upp köldmediet som finns i det slutna systemet i värmepumpen, man använder ett medium som har väldigt låg kokpunkt. Köldmediet förångas och förs vidare till en kompressor där gasen komprimeras, vilket gör den ännu varmare. Den heta gasen går vidare till värmepumpens kondensor där den avger sin värme till vattnet som cirkulerar i husets värmesystem. När köldmediet har avgett sin värme svalnar den och blir genom kondensation flytande igen. Köldbäraren kyls ned av det avsvalnade köldmediet och förs därefter ner i berget för att återigen bli uppvärmt.