Ground Source Heat Pump Information

What is a heat pump and how does it work?

A heat pump is an electrical device that extracts heat from one place and transfers it to another. The heat pump is not a new technology; it has been used in Sweden and around the world for decades. Refrigerators and air conditioners are both common examples of heat pumps. Heat pumps transfer heat by circulating a substance called a refrigerant through a cycle of alternating evaporation and condensation. A compressor pumps the refrigerant between two heat exchangers. In one heat exchanger, the evaporator, the refrigerant is evaporated at low pressure and absorbs heat from its surroundings. The refrigerant is then compressed en route to the heat exchanger, the condenser, where it condenses at high pressure. At this point, it releases the heat it absorbed earlier in the cycle. Radiator borehole etc

Can anyone have rock-/ground-/lake source heating?

It completely depends on the circumstances. If you have a rock shelf not too far beneath the surface of the ground it is no problem. If you have a large plot or fields around the house, ground source is a very good alternative because it is many times cheaper to install. If your house is near a lake and you have a lake plot with permission to use water source heating this is also a good alternative.

How deep must the collector be between the bore hole and the house?

The collector should be laid about 1 m deep and act as a ground collector on the way to the house. Incoming and outgoing pipes should be separated or insulated from each other.

Will the heat in my bore hole run out?

The heat that is taken from the ground comes from the sun's rays and as long as the sun shines the ground is recharged during the summer months provided that the installation is correctly dimensioned. The ground operates as a gigantic battery where water conducts new heat into your bore hole.

We are a family of four, is the integrated water heater of 160 litres enough?

That completely depends on what your hot water consumption is as a family. In normal use 160 litres is fine for a family. If one has a jacuzzi that is used frequently one should perhaps consider either supplementing with an external hot water heater select an 11-model with external accumulator tank.

I have a pool, wood boiler and a solar panel. Can I use these together with the heat pump?

Heat pumps and other products, such as boilers and hot water heaters, are designed to be compatible with lots of different products and operating conditions. NIBE recommends different solutions for dockings between different systems. These can be found in 'Installation and Maintenance Instructions' which can be downloaded.

How should one isolate the collector at the house?

The collector must be insulated for the last few metres (at least 2 m) to the house. This is to avoid freezing around the collector with frost ruptures as a result.

Why dimension with an immersion heater at the core, isn't it better to have a more powerful compressor and therefore use less expensive electricity?

A heat pump is dimensioned for best operation and that is obtained if it is too little for the coldest days of the year (which is when the immersion heater kicks in) and just right for the rest of the year.

How many starts of the compressor is normal per day/year?

That varies quite a lot, it depends on how many hours the compressor runs in a year. Normal number of compressor hours is anything from 3000 to 4500 hours/year. As a result of this there are more starts if the hours are fewer. Likewise if the starts are fewer the hours are more. Normal number of starts is anything from 4000 to 16000 starts/year. There may be even more in special circumstances.