Plus energy house with hydronic pellet stove + WWWP for cooling?

Hello everyone,

I have been reading along here with interest for some time now. Now I want to start a topic myself and hope for many good ideas, food for thought, and tips.

We have been considering building a house for some time but are still in the collection and planning phase. According to our current ideas, it should be an Effizienzhaus Plus, although I am not entirely sure yet whether that really pays off (but I will open a separate topic about that). It is supposed to be a prefabricated house. The providers’ plans all basically seem to include a central ventilation system with heat recovery as well as photovoltaics.

We have now essentially made two considerations: We would like to have a wood stove for coziness. Economic efficiency plays a subordinate role here. According to our research, we have found stoves that are water-bearing and release at most 15-20% of the heat directly into the air, so at least 80-85% can be used for heating and hot water production. We thought that an automatic pellet stove would be very suitable in winter, when there is little sun, to support or even completely take over the heating and hot water production. Actually a nice side effect. However, an energy consultant told us that it is almost impossible to operate a water-bearing pellet stove sensibly in such a well-insulated house, since the direct heat output is already significantly too high. Is that true? Does anyone have experience with this? And shouldn’t the central ventilation distribute the heat cleverly throughout the entire house? Do we perhaps have to give up our dream of a wood stove because it is not sensibly combinable with a Plus-energy house?

The second point is cooling. Since I moved out of my parents’ house, I have always lived in rental apartments that have become much too warm in summer, sometimes 26-28 degrees or even more, despite shading and nighttime ventilation. I really don’t want that anymore. Who should sleep properly under those conditions? Alongside automatic shading (roller shutters on all windows), we have therefore thought about a central air conditioning system. After some research, we found out that a heat pump can also cool. Of course, a heat pump also offers advantages throughout the rest of the year. Therefore, our idea was to combine the system with a (preferably) water-to-water heat pump. In summer, it could cool our house, especially the bedroom, down to tolerable temperatures (maximum 22 degrees in the bedroom at night and 24 degrees in the important living areas during the day) and otherwise support heating and hot water production. Incidentally, the wells of the wwwp can also be used for automatic garden irrigation, which makes sense anyway.
Is such a variant more economical than conventional air conditioning? Or would another heat pump technology be worth considering? Does anyone here cool with a heat pump? What are the experiences?

We are really grateful for any tip or food for thought as well as further information. If more information is needed, please just ask.

Thanks in advance for your answers.

Best regards
Ddorfer

thought about a central air conditioning system. After some research, we found out that a heat pump can also cool.

Air conditioning cools properly, a heat pump is a drop in the ocean. Once it gets warm in the house, the heat pump won't help you either.

You address many things that are subjectively evaluated and answered.
My opinion: A water-bearing fireplace is unnecessary, too expensive, and you bring unnecessarily much technology into the house. You can still set up a wood-burning stove, especially from a "cozy" perspective and not counted in the house concept. Of course, you will overheat your hut with it – so what? Then you just open the windows while the fireplace is running – it's not efficient – but cozy.
Cooling with the heat pump: You don’t cool the air with the heat pump, but the floor, meaning you send cold water through the underfloor heating so that the room cools down. In many commercial units, "cooling ceilings" are installed, where exactly this is done. Cold air sinks, which is why this works quite well; does it also cool upwards with a cold floor? Better a decentralized air conditioner or a proper one via [Kontrollierte-Wohnraumlüftung], then be careful with condensation.
Garden irrigation (fully automated) makes sense? That depends on the garden, the location, and the precipitation where you are. For me, it doesn’t make sense... I can water ten times in summer anyway...
Whether a garden well pays off has already been intensely discussed here, a garden well in the suction shaft of the heat pump? I’m curious whether that is technically possible and sensible, you don’t want to suck your heat pump water through the garden pump and then be without a heat pump, do you?
Regarding the [energiePlus Haus], I’m missing your concept concerning photovoltaic, storage, power management, etc. Do you want to generate more only on paper or actually be independent (including household electricity)?

The air conditioning cools properly, the heat pump is just a drop in the bucket. Once it gets warm in the house, the heat pump won't help you either.

Well, that would be my question for those who use such a solution: Is the cooling with the heat pump sufficient? A suitably insulated house with a shading system should not heat up so much anyway, so the 2-3 degrees reduction with the heat pump should already be enough, shouldn't it? I would appreciate any experiences.

An air conditioner would of course have the advantage of better cooling performance. The electricity costs should not be so dramatic considering a photovoltaic system on the roof, since plenty of electricity is generally available in summer anyway.

The annoying thing about the current energy systems is still that a large part of the electricity generation occurs in summer, but the consumption for heating is greatest in winter. A pellet stove could help with that, or perhaps the mini wind turbine on the roof.

Good morning

Alternatively, a system with evaporative cooling might also be interesting as an alternative to the air conditioning.



Olli

A properly insulated house with a shading system should not heat up as much

That is a misconception. The house heats up just as much as an old property. It just takes longer for the heat to get inside the house and then also longer for you to get it out again.