ᐅ Experience with spiral collectors / ground heat exchangers

mading schrieb:
Hi,

I would be more cautious. If I understand correctly, it’s similar to ground coils, which are usually installed over large areas at depths of about 2-3 meters (6.5-10 feet). As far as I know as a non-expert, there isn’t much long-term experience with them. If something goes wrong, you have to dig up a large area.

With a required space of about 4x4 meters (13x13 feet), it is probably negligible. Also, some manufacturers offer warranties on the coils since they are basically maintenance-free. Of course, anything can happen, but I prefer this system over an air-to-water heat pump because I can manage even at -20°C (-4°F) without an electric heating element. Deep drilling is pointless in our area, so alternatives are limited. In any case, an electric heating element is a no-go for us...

I was told that you can install a rainwater infiltration system above the baskets to keep the soil around them more moist, which increases thermal conductivity. By the way, two collectors always run in one circuit. If something is leaking, you probably don’t have to excavate all of them. The material is supposed to be extremely durable.

A surface collector might be an advantage if you have as much space as you do ^^ We will have 900 sq m (9700 sq ft) but with a house and a double garage.. Some trees. In the rest of the garden, I still want to be able to build something, for example a pool. Otherwise, surface collectors would be more suitable.

Your acquaintance only has 5 baskets? Then I assume it’s a smaller house!

We definitely will not use an air source heat pump. Gas and solar would be the cheapest option, but gas probably won’t stay that affordable over the next 30 years. That’s why I’m grateful for any user experiences regarding spiral collectors. I do know a colleague who was very satisfied with them, but I like to hear from more people who actually have them and can share solid feedback ^^

The company we want to build with heats a 200m² (2,150 ft²) house using four baskets... The ground-source heat pump has a COP of 5 and is a Weider SW70.

Is it a Passive House? And are these spiral collectors or deep boreholes? For 190 m² (2,045 sq ft), we would need over 10 units, according to initial information.

It is a KfW40+ house with spiral collectors, meaning ground heat exchangers.

Ok, in this case, 4 pieces might be enough ^^