ᐅ Using Rainwater and Greywater for Brine Water Heat Pumps

Created on: 16 Oct 2021 08:05
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Plonk109
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Plonk109
16 Oct 2021 08:05
Hello,

We want to heat our home using a brine water heat pump. As an energy source, we plan to use energy baskets through which both rainwater and treated sewage water from the septic tank will infiltrate. Infiltration is permitted. The groundwater level is such that the baskets would be submerged in the groundwater at an installation depth of about 4m (13 feet), if I am not mixing up any terms here. The water dispersal is then planned to be via soakaways.

Good idea or rather a pointless plan?
Thanks for your thoughts and opinions!
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konibar
16 Oct 2021 10:48
Interesting idea!

EnergieKörbe refers to suction baskets with coarse/fine filters for intake or storage tanks (fresh water) standing in the groundwater (= heat exchanger)?

That sounds like quite a bit of maintenance, so everything should remain easily accessible.

What volume of available groundwater supply are you planning for in cubic meters?
You can harvest about 1.2 kWh/m³*K.
With an estimated water temperature of 12°C (54°F) in winter, 1 cubic meter of water will start to freeze after extracting approximately 14 kWh, unless enough warm water flows in from the sides.

Interesting, but the sizing seems a bit vague to me.

If the heat pump can be reversed, you could introduce the waste heat from the A/C there in summer.
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Plonk109
16 Oct 2021 10:53
I am not an expert in the details and therefore cannot provide specific values; the idea came to me based on my basic understanding of physics. We are building in a marsh area.

The baskets are simple metal cages, 3-4 meters long (10-13 feet), to which the absorber pipes are attached. Another idea would be to design everything as an infiltration shaft and place the baskets underneath. Whether something like this is even feasible is beyond my knowledge; we were only told that rainwater infiltration through absorber mats would increase efficiency.
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guckuck2
16 Oct 2021 12:03
A moist ground or precipitation is generally very suitable for shallow collectors, whether traditional flat collectors, baskets, trenches, or any other type. As long as the other involved trades do not see any issues with it, I think the idea is reasonable.
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euro910
13 Jul 2024 11:46
Hello,

I am currently researching this exact topic online:
Soakaway with trench collector or ground heat exchanger for additional heat input.

Have you implemented it this way?
Or are there other readers who have gained experience with this?
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Rübe1
13 Jul 2024 13:03
The baskets or collectors regenerate through the water, which is good so far. Installing a soakaway above them is therefore not a bad idea.

Whether this whole setup is worthwhile, however, is a completely different matter. Proper design, heat load calculation, and so on are necessary for that.