Guest 34

Hmm almost. It is indeed very expensive considering there won't be much in the way of support in the UK for this product. In the second page, you see two pipes nicking some heat from the return pipe which then gets stepped up and dumped in the water cylinder. This is half of what I hoped might exist. So forget about DHW for now and consider another application for a water-to-water HP. Just erase the cylinder in that picture and replace it with two more pipes. Those pipes would be hotter than the flow provided by the outside HP. In my case, I have two UFH manifolds but one needs a higher flow temperature than the other. I know I can get an electronic valve mixer for the UFH that needs a lower flow temp and set a higher heating curve on the boiler so that the other UFH zone gets hotter. No luck finding anyone that would do this in my area though which is why I'm just day-dreaming on an internet forum before bedtime 😅. If I could get a heat pump to boost the flow temperature, on just the one manifold that needs it, I could keep my boiler's heating curve low AND increase condensation efficiency (by making the return colder, without increasing the flow temp). So yes, I'd use more electricity and gas, but it still might be more efficient than just increasing the flow temp and having one zone constantly overshoot. Thanks for digging that up though. Seems like a great product, shame about the price.

Yes that's what I'm looking for. The energy will be added by the boiler. Do you happen to remember any keywords (topic, company, product name, etc...?).

EASHP still use air as their source and usually have a DHW cylinder attached to them so not as flexible in what applications they can be used in. A 2nd stage cascade module would be a water-to-water (4 ports, all water pipes) mono bloc heat pump (or gas heat exchange ones but you need all the associated refrigeration equipment to install them). It seems they only exist in the commercial space.

This article clarifies what I'm talking about (the term has different meanings to different people). https://www.linkedin.com/pulse/is2-heat-pumps-cascade-graham-hendra/ I'm only looking for the second stage (i.e., the indoors heating pump). As in, a water-to-water monobloc heat pump that is not a GSHP system. I'm looking for something that is small and any plumber could plumb in that simply boosts the flow temperature of a hydronic heating system by lowering the temperature of the return pipe. These systems are usually quite big and expensive as they are only used in the commercial space. The closest consumer grade product I've found is the Mixergy iHP (Daikin, Vaillant, Dimplex and others have similar offerings). They are indoor heat pumps that take low entropy created by your central heating system (gas boiler, monobloc ASHP, air-to-air mini split, etc...) and concentrate it to give you hot water (higher temperature than what your heating system provides). The link between the two stages in this scenario is too weak and inflexible (CH, heats water in pipe, pipe heats emitter, emitter heats air, iHP uses air to heat up a coil..., hot water). I'm looking for something that is very small, something the size of a portable air conditioner or even a dehumidifier (200 electrical watts or thereabouts). Instead of fans and radiators, you would have braised heat exchangers (kind of like the desuperheater pool heaters you can find in the US, but again, smaller). You would connect your return flow pipe to the evaporator heat exchanger and the flow to the condenser heat exchanger. That way, you can use your central heating (whatever it is, you just need it to produce hot water that circulates) to heat your hot water tank. In the case of a gas/oil boiler, you can make it more efficient as you would be lowering the return pipe temperature (I know about gas savers, I'm looking for something different).

Emailed Salus and was told they'd be coming to the UK in Spring this year. I'd add a month or 20 to that estimate to avoid too much disappointment.

I'm just a homeowner trying to reverse some "always done it that way" nonsense in my house. It's a losing battle. I've come here to share the pain