- #1
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- TL;DR Summary
- Use the waste warm water from your plumbing system.
I was enjoying my (very short) hot shower this morning and realized that the lovely warm water was flowing over my body (sorry - too much information) only once and then disappearing down the drain.
This water - and what comes out of the washing machine, dishwasher etc. could be at a seriously 'useful' temperature for a heat pump. There must be many kWh lost over a day. You can find systems for shower heat recovery, advertised but they seem to be passive and are low hanging fruit, afaics. A whole house system would be better and would involve a hot water storage tank (which I have).
Obviously the heat exchanger plumbing would need to be maintained (cleaned out) on a regular basis and I would imagine that separate drainage would be needed for foul water. Also, the discharge water temperature would need to be well above freezing but the usable heat would be a lot more, per electrical kWh, than what can be obtained from an air source heat pump in winter. An installation could be a lot cheaper than heat pumps that are being considered today.
Many years ago I heard of a scheme to recycle heat from a house via a ventilation system where outgoing air is passed through a heat exchanger to warm up incoming air. That's a similar principle.
I ask myself why there aren't dozens of these alternative systems to be found working in houses all ov er the country.
This water - and what comes out of the washing machine, dishwasher etc. could be at a seriously 'useful' temperature for a heat pump. There must be many kWh lost over a day. You can find systems for shower heat recovery, advertised but they seem to be passive and are low hanging fruit, afaics. A whole house system would be better and would involve a hot water storage tank (which I have).
Obviously the heat exchanger plumbing would need to be maintained (cleaned out) on a regular basis and I would imagine that separate drainage would be needed for foul water. Also, the discharge water temperature would need to be well above freezing but the usable heat would be a lot more, per electrical kWh, than what can be obtained from an air source heat pump in winter. An installation could be a lot cheaper than heat pumps that are being considered today.
Many years ago I heard of a scheme to recycle heat from a house via a ventilation system where outgoing air is passed through a heat exchanger to warm up incoming air. That's a similar principle.
I ask myself why there aren't dozens of these alternative systems to be found working in houses all ov er the country.