Connecting and Testing Vertical Collector for the Heat Pump

The first photo is showing a testing procedure for vertical collector. Each vertical collector should be tested before connected to the heat pump. It is very small possibility of leaking, but you must be 100% sure. Testing is accomplished with water and a water pump (hand driven) which can produce a pressure up to 5 bar. Pressure meter must be stable at least 1 hour – 1 hour the same pressure.

The second photo is showing pipes already connecting vertical collector and heat pump. There is a 0,75 to 1 meter deep channel where pipes are placed.

Pipes for Geothermal Collector

Pipes for geothermal collector are very important part of heat pump system. For 100 meters of vertical geothermal collector that is inserted into drilled hole, we usually need 400 meters of strong pipes (2 pipe loops inserted in one hole). If we calculate the water pressure at the end of 100 meters collector (100 meters deep under the surface) we get 10 bars (1 bar / 10 meters). We must add another 2 bars to get optimal working conditions for the heat pump. That is way pipes must be strong and must stand at least 12 bars of pressure for 100 meters collector. We have used 16 bar pipes (32mm in diameter, 3 mm wall thickness, PE 100, SIST EN 12201) from Slovene (Europe) producer.

Drilling the hole, close-up

This is a close-up photo of drilling the hole for my heat pump project. Parallel to drilling we have chosen pipes for vertical geothermal collector. Special pipes were used. We have used more than 1000 meters.

Drilling the hole (well) for geothermal vertical collector

And then we started … I went into action and made a deal with one drilling and mining company from my country to drill holes. It is important to make a real contract for this service and to sign the contract from both parties (you and company). Important things about the contract:

• article with deadline and penalties for not meeting the deadline must be included


• article about possible damages made by company and their responsibilities (e.g. in case where the driller damages your house, because he was not careful enough when he was moving the drilling machine – see it on the picture)


• If you are not sure, see legal advisor

We first planned to drill two holes for 100meters. The first one was O.K. When drilling the second one some problems occurred, the hole (well) was not stable enough and we only reached about 60 meters. According to the calculations 160 was not enough, so we made the third well for another 60 meters. Together we have 220 meters.
Important things:

• wells or holes should not be to close together, it is recommended to keep 10m distance between two wells


• It is quite noisy when drilling,… your neighbors will complain if you will not inform them in advance


• It could be quite messy around drilling machine and underground water could erupt from the hole


• If you already have a house with nice colored façade and the machine in near the house, be sure to protect the house and window

We were drilling about 14 days.