ᐅ Plus-energy house with a hydronic pellet stove and a ground source heat pump for cooling?
Created on: 29 Feb 2016 23:55
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DdorferHello everyone,
I have been following this forum with interest for some time now. I would like to start a topic myself and hope for lots of good ideas, suggestions, and tips.
We have been considering building a house for a while, but we are still in the research and planning phase. According to our current ideas, it should be a Plus Energy House, although I am still not entirely sure if it will be cost-effective (I plan to start a separate discussion on that). It will be a prefabricated house. The providers’ plans generally include a central ventilation system with heat recovery and photovoltaic panels.
We have mainly two points to consider: We would like to have a wood-burning stove for coziness. Economic efficiency plays only a minor role here. From our research, we found stoves that are hydronic, releasing only 15-20% of the heat directly into the room air, meaning at least 80-85% can be used for heating and hot water production. We thought an automatic pellet stove would be well suited to support or even fully cover heating and hot water needs during winter when there is little sun. This would be a nice bonus. However, an energy consultant told us that it is almost impossible to operate a hydronic pellet stove efficiently in such a well-insulated house because the direct heat output is already too high. Is that true? Does anyone have experience with this? Shouldn’t the central ventilation system distribute the heat effectively throughout the house? Do we possibly have to give up our dream of a wood-burning stove because it doesn’t work well in combination with a Plus Energy House?
The second point is cooling. Since moving out of my parents’ house, I have always lived in rented apartments that became far too warm in summer, sometimes 26-28°C (79-82°F) or even higher, despite shading and night ventilation. I definitely don’t want to experience that anymore. Who can sleep properly under such conditions? In addition to automatic shading (roller shutters on all windows), we have therefore been thinking about a central air conditioning system. After some research, we found out that a heat pump can also provide cooling. Of course, a heat pump also offers benefits during the rest of the year. Therefore, our idea is to combine the system with a (preferably) water-to-water heat pump. In summer, it could cool our house, especially the bedrooms, to comfortable temperatures (max. 22°C (72°F) in the bedrooms at night and 24°C (75°F) in the main living areas during the day) and otherwise support heating and hot water production. Additionally, the wells for the water-to-water heat pump could be used for automatic garden irrigation, which makes sense anyway. Is such a solution more cost-effective than conventional air conditioning? Or would another heat pump technology be worth considering? Does anyone here cool their home with a heat pump? What are your experiences?
We are truly grateful for any tips, suggestions, or further information. If more details are needed, just ask.
Thanks in advance for your replies.
Best regards,
Ddorfer
I have been following this forum with interest for some time now. I would like to start a topic myself and hope for lots of good ideas, suggestions, and tips.
We have been considering building a house for a while, but we are still in the research and planning phase. According to our current ideas, it should be a Plus Energy House, although I am still not entirely sure if it will be cost-effective (I plan to start a separate discussion on that). It will be a prefabricated house. The providers’ plans generally include a central ventilation system with heat recovery and photovoltaic panels.
We have mainly two points to consider: We would like to have a wood-burning stove for coziness. Economic efficiency plays only a minor role here. From our research, we found stoves that are hydronic, releasing only 15-20% of the heat directly into the room air, meaning at least 80-85% can be used for heating and hot water production. We thought an automatic pellet stove would be well suited to support or even fully cover heating and hot water needs during winter when there is little sun. This would be a nice bonus. However, an energy consultant told us that it is almost impossible to operate a hydronic pellet stove efficiently in such a well-insulated house because the direct heat output is already too high. Is that true? Does anyone have experience with this? Shouldn’t the central ventilation system distribute the heat effectively throughout the house? Do we possibly have to give up our dream of a wood-burning stove because it doesn’t work well in combination with a Plus Energy House?
The second point is cooling. Since moving out of my parents’ house, I have always lived in rented apartments that became far too warm in summer, sometimes 26-28°C (79-82°F) or even higher, despite shading and night ventilation. I definitely don’t want to experience that anymore. Who can sleep properly under such conditions? In addition to automatic shading (roller shutters on all windows), we have therefore been thinking about a central air conditioning system. After some research, we found out that a heat pump can also provide cooling. Of course, a heat pump also offers benefits during the rest of the year. Therefore, our idea is to combine the system with a (preferably) water-to-water heat pump. In summer, it could cool our house, especially the bedrooms, to comfortable temperatures (max. 22°C (72°F) in the bedrooms at night and 24°C (75°F) in the main living areas during the day) and otherwise support heating and hot water production. Additionally, the wells for the water-to-water heat pump could be used for automatic garden irrigation, which makes sense anyway. Is such a solution more cost-effective than conventional air conditioning? Or would another heat pump technology be worth considering? Does anyone here cool their home with a heat pump? What are your experiences?
We are truly grateful for any tips, suggestions, or further information. If more details are needed, just ask.
Thanks in advance for your replies.
Best regards,
Ddorfer
N
nordanney1 Mar 2016 07:31Ddorfer schrieb:
considered a central air conditioning system. After some research, we found out that a heat pump can also provide cooling. An air conditioning system cools effectively, while a heat pump only offers minimal relief. Once the house heats up, the heat pump won’t be much help.
You bring up many points that are subjective and depend on personal preferences.
In my opinion, a water-heated fireplace is unnecessary, too expensive, and adds a lot of complicated technology to your home. You can still install a wood-burning stove just for the cozy atmosphere, without integrating it into your overall house design. Of course, it will overheat your place – so what? You just open the windows while the stove is running. It’s not efficient, but it’s cozy.
Cooling with a heat pump: You don’t cool the air with a heat pump; instead, you cool the floor by running cold water through the underfloor heating system to lower the room temperature. Many commercial buildings use "cooling ceilings," which work on a similar principle. Cold air sinks, so it works pretty well. But does a cold floor also cool the air above it? It’s better to use a decentralized air conditioning unit or a proper system integrated into a controlled ventilation system with heat recovery—just watch out for condensate management.
Does fully automated garden irrigation make sense? That depends on your garden, location, and rainfall. For me, it doesn’t make sense… I can water manually 10 times during the summer.
Whether a garden well is cost-effective has already been heavily debated here. As for using a garden well as the intake for the heat pump? I’m curious if that’s technically possible and practical. After all, you wouldn’t want your heat pump’s water to be pumped out through the garden pump, leaving you without your heat pump system.
Regarding the energy-plus house, I’m missing your plan for photovoltaics, storage, and power management. Do you just want to generate more energy on paper, or do you aim to be truly independent (including household electricity)?
In my opinion, a water-heated fireplace is unnecessary, too expensive, and adds a lot of complicated technology to your home. You can still install a wood-burning stove just for the cozy atmosphere, without integrating it into your overall house design. Of course, it will overheat your place – so what? You just open the windows while the stove is running. It’s not efficient, but it’s cozy.
Cooling with a heat pump: You don’t cool the air with a heat pump; instead, you cool the floor by running cold water through the underfloor heating system to lower the room temperature. Many commercial buildings use "cooling ceilings," which work on a similar principle. Cold air sinks, so it works pretty well. But does a cold floor also cool the air above it? It’s better to use a decentralized air conditioning unit or a proper system integrated into a controlled ventilation system with heat recovery—just watch out for condensate management.
Does fully automated garden irrigation make sense? That depends on your garden, location, and rainfall. For me, it doesn’t make sense… I can water manually 10 times during the summer.
Whether a garden well is cost-effective has already been heavily debated here. As for using a garden well as the intake for the heat pump? I’m curious if that’s technically possible and practical. After all, you wouldn’t want your heat pump’s water to be pumped out through the garden pump, leaving you without your heat pump system.
Regarding the energy-plus house, I’m missing your plan for photovoltaics, storage, and power management. Do you just want to generate more energy on paper, or do you aim to be truly independent (including household electricity)?
nordanney schrieb:
The air conditioner cools effectively; the heat pump is just a drop in the ocean. Once the house gets warm, the heat pump won't help you much.Well, that would be my question for those using such a solution: Is the cooling provided by the heat pump sufficient? A properly insulated house with a shading system shouldn’t heat up that much, so a 2-3 degree Celsius (4-5 degrees Fahrenheit) reduction from the heat pump should be enough, right? I would appreciate hearing about your experiences.
An air conditioner would, of course, have the advantage of better cooling performance. Considering a photovoltaic system on the roof, electricity costs shouldn’t be too significant, since there is plenty of power available in summer anyway.
The drawback with current energy systems remains that most electricity production happens in summer, while heating demand peaks in winter. A pellet stove could help with this, or perhaps a small wind turbine on the roof after all.
N
nordanney2 Mar 2016 07:24Ddorfer schrieb:
A properly insulated house with a shading system shouldn’t heat up that much That is a misconception. The house heats up just as much as an older building. It just takes longer for the heat to get inside the house and then also longer for you to get it back outside.
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