ᐅ Underfloor heating in the children's room? Some rooms planned without underfloor heating? Removing the air-to-water heat pump?
Created on: 18 Dec 2019 21:20
L
ludwig88sta
Hello everyone,
I'll briefly introduce the topic:
We are planning a two-story single-family house of about 180 sqm (1,940 sq ft) with a basement, built with Poroton 42cm (16.5 inches) bricks and as much photovoltaic system as possible on the roof. Since we want to insulate well not only with the bricks but also with the windows, the base slab, the basement, etc., we are considering an air-to-water heat pump (following the motto "a well-insulated house doesn’t need a huge heating system").
Now we are wondering whether we should install underfloor heating in the bedroom or children’s rooms at all, because it is said to be slow to react and can cause uncomfortable temperatures in summer, which again leads to poor sleep. Also, different temperatures are needed in sleeping areas than in living areas. Of course, children’s rooms are tricky since they are used for both activities in the afternoon and for sleeping at night.
We want to install underfloor heating in the kitchen/dining area, living room, and of course the bathroom. Can you plan for two different supply temperatures for the underfloor heating (one warmer for kitchen/dining, living room, bathroom, study and one cooler for bedrooms and kids’ rooms)? What about rooms like the hobby room or guest room? My wife often makes wreaths or works on crafts in the hobby room, so it definitely does not need to be as warm as the living room. The guest room we would not want to heat throughout the entire heating season, but only when guests are actually staying.
However, I read that underfloor heating works best when water is circulated continuously? What is recommended for guest rooms or hobby rooms? The quickest way to heat them would probably be with conventional radiators rather than underfloor heating? But what I have read so far suggests that air-to-water heat pumps may not be ideal for that. Should we consider a gas boiler instead (connection available on the property)? Or is it possible to operate underfloor heating with an air-to-water heat pump with different supply temperature circuits (1) living areas 2) sleeping areas 3) rooms heated only as needed)?
This sentence made me doubt:
I understand this to mean that the whole house should be heated with one supply temperature, ideally all through underfloor heating. Of course, with multiple circuits since each circuit should not exceed 80/100 meters (260/330 feet) in length (pressure loss, etc.). But all with the same supply temperature, otherwise that would be individual room control again, which should not be installed.
I hope you can shed some light on this.
Underfloor heating is very important to my wife, so we won’t avoid it. The question is what we do with the hobby room, which needs much less heating (or also the bedrooms and kids’ rooms?), and the guest room, which is heated much less often. Is that even possible with underfloor heating and an air-to-water heat pump?
Have a great evening and enjoy the upcoming pre-Christmas season.
I’m really impressed by the many helpful people here who support future homeowners like me, who don’t just go to a general contractor and say “Do it and give me the keys sometime, I don’t care about the details,” but who want to dive into all the different trades involved. At the same time, it can be overwhelming and confusing due to the huge amount of information available online, especially with little prior experience.
I'll briefly introduce the topic:
We are planning a two-story single-family house of about 180 sqm (1,940 sq ft) with a basement, built with Poroton 42cm (16.5 inches) bricks and as much photovoltaic system as possible on the roof. Since we want to insulate well not only with the bricks but also with the windows, the base slab, the basement, etc., we are considering an air-to-water heat pump (following the motto "a well-insulated house doesn’t need a huge heating system").
Now we are wondering whether we should install underfloor heating in the bedroom or children’s rooms at all, because it is said to be slow to react and can cause uncomfortable temperatures in summer, which again leads to poor sleep. Also, different temperatures are needed in sleeping areas than in living areas. Of course, children’s rooms are tricky since they are used for both activities in the afternoon and for sleeping at night.
We want to install underfloor heating in the kitchen/dining area, living room, and of course the bathroom. Can you plan for two different supply temperatures for the underfloor heating (one warmer for kitchen/dining, living room, bathroom, study and one cooler for bedrooms and kids’ rooms)? What about rooms like the hobby room or guest room? My wife often makes wreaths or works on crafts in the hobby room, so it definitely does not need to be as warm as the living room. The guest room we would not want to heat throughout the entire heating season, but only when guests are actually staying.
However, I read that underfloor heating works best when water is circulated continuously? What is recommended for guest rooms or hobby rooms? The quickest way to heat them would probably be with conventional radiators rather than underfloor heating? But what I have read so far suggests that air-to-water heat pumps may not be ideal for that. Should we consider a gas boiler instead (connection available on the property)? Or is it possible to operate underfloor heating with an air-to-water heat pump with different supply temperature circuits (1) living areas 2) sleeping areas 3) rooms heated only as needed)?
This sentence made me doubt:
"To ensure optimal operation of the heat pump, underfloor heating should not have individual room control installed."(Source: Bundesverband Flächenheizung e.V.)
I understand this to mean that the whole house should be heated with one supply temperature, ideally all through underfloor heating. Of course, with multiple circuits since each circuit should not exceed 80/100 meters (260/330 feet) in length (pressure loss, etc.). But all with the same supply temperature, otherwise that would be individual room control again, which should not be installed.
I hope you can shed some light on this.
Underfloor heating is very important to my wife, so we won’t avoid it. The question is what we do with the hobby room, which needs much less heating (or also the bedrooms and kids’ rooms?), and the guest room, which is heated much less often. Is that even possible with underfloor heating and an air-to-water heat pump?
Have a great evening and enjoy the upcoming pre-Christmas season.
I’m really impressed by the many helpful people here who support future homeowners like me, who don’t just go to a general contractor and say “Do it and give me the keys sometime, I don’t care about the details,” but who want to dive into all the different trades involved. At the same time, it can be overwhelming and confusing due to the huge amount of information available online, especially with little prior experience.
If you need to heat 180 m² (1,937 sq ft) with a basement, a horizontal ground loop collector would be significantly more efficient compared to an air-to-water heat pump. For 1,000 m² (10,764 sq ft), I would strongly lean towards a horizontal ground loop collector in your situation.
If science says so, then please provide sources.
I used to be part of the "always keep the bedroom window open" group as well. However, with a ventilation system (constant fresh air...) and underfloor heating (even temperature, no uncomfortable radiant heat...), that changed.
I used to be part of the "always keep the bedroom window open" group as well. However, with a ventilation system (constant fresh air...) and underfloor heating (even temperature, no uncomfortable radiant heat...), that changed.
ludwig88sta schrieb:
This brings us back to the topic. Some people can sleep with light, others prefer complete darkness. Some need 15°C (59°F) to sleep. Others—like you—can sleep well at 20°C (68°F). However, I would also bring science and medicine into the discussion, which to my knowledge recommend temperatures below 20°C (68°F) in the bedroom. But to each their own. This is technically not possible in a new build. All rooms are within the same thermal envelope. Even an unheated room will be warmed indirectly through doors and walls (which are usually not insulated).
Our pantry heating is turned off—I would say it’s at most one degree cooler than the adjacent kitchen, even though the door is always closed and the heater is off.
Since the kitchen has to heat more to compensate for the pantry being indirectly heated by the kitchen, the energy savings will be close to zero. My wife just prefers the heating off in the pantry.
You won’t be able to maintain 18°C (64°F) in the bedroom and 23°C (73°F) in the bathroom in a new build. To achieve that, you would technically have to cool the bedroom even in winter.
What you’re trying to do here is transfer the feel of an old building to a new build. If you want something close to the old building experience, build a house following the energy saving ordinance with a gas boiler and trickle vents in the window frames.
Quite a bit has already been discussed, and I thought you had already picked up some points from the conversations yesterday.
As many others have already said, a system with multiple supply temperatures or a mix of underfloor heating plus radiators, etc., doesn’t make sense at all. It will cost you a lot, and you will have to buy and install (or have installed) a lot of unnecessary technology. Alternatively, you might take the opposite approach and leave out larger areas or entire rooms. That’s shooting yourself in the foot.
A modern house is usually designed for low supply temperatures and outdoor temperature control. This means it heats 24/7 continuously, or the system runs without external adjustments, completely independent of the type of heating or energy source. What’s important is a precise calculation of the system and a professional installation afterwards. It is especially important to ensure that the heating circuits are not too long and that the pipe spacing is designed according to the intended use of the rooms. The edge zones, especially at floor-to-ceiling windows, often require tighter spacing. Toward the center of the room, the spacing can be larger.
This means: an efficient underfloor heating system has variable pipe spacing depending on the boundary conditions and is not rigidly set to, for example, 10, 15, or 20cm (4, 6, or 8 inches) throughout the whole room.
The hydraulic balancing is, by the way, almost always mandatory for any type of water-based heating (yes, also with radiators). However, this is considered the top level, and this is where you find out whether the installer is competent or not.
Different temperatures in rooms are achieved by understanding the physics of the heating system and the building. The whole is a heated envelope, not several separate ones — even if you completely turn off heating in one room, it will still be warmed from the neighboring rooms. So in the end, you basically don’t save anything; you just shift the demand. Even though, for calculation purposes, the rooms are considered separately.
The Energy Reference Ratio (ERR) is a politically motivated concept and has its justification with radiators and other fast-acting heating systems. However, with low-temperature underfloor heating, the ERR hardly has any impact and is as unnecessary as a goiter. Here, I recommend reading about the “self-regulating effect.” Feel free to ask in the forum who has an ERR and whether they constantly adjust the thermostats or if once set, they have never been touched again.
Furthermore, you can simply adjust temperatures via the heat carrier flow at the heating circuit valve (HKV) – the hydraulic fine balancing. This is done during the first or second heating season. After that, you generally don’t need to adjust the system again. However, keep in mind that large temperature differences are not possible in a modern house (without permanently opening windows). Typically, you can achieve a 2 to 3°C (4 to 5°F) difference between rooms. With a mechanical ventilation system with heat recovery, it’s even less, as it constantly exchanges and distributes air between the rooms.
As many others have already said, a system with multiple supply temperatures or a mix of underfloor heating plus radiators, etc., doesn’t make sense at all. It will cost you a lot, and you will have to buy and install (or have installed) a lot of unnecessary technology. Alternatively, you might take the opposite approach and leave out larger areas or entire rooms. That’s shooting yourself in the foot.
A modern house is usually designed for low supply temperatures and outdoor temperature control. This means it heats 24/7 continuously, or the system runs without external adjustments, completely independent of the type of heating or energy source. What’s important is a precise calculation of the system and a professional installation afterwards. It is especially important to ensure that the heating circuits are not too long and that the pipe spacing is designed according to the intended use of the rooms. The edge zones, especially at floor-to-ceiling windows, often require tighter spacing. Toward the center of the room, the spacing can be larger.
This means: an efficient underfloor heating system has variable pipe spacing depending on the boundary conditions and is not rigidly set to, for example, 10, 15, or 20cm (4, 6, or 8 inches) throughout the whole room.
The hydraulic balancing is, by the way, almost always mandatory for any type of water-based heating (yes, also with radiators). However, this is considered the top level, and this is where you find out whether the installer is competent or not.
Different temperatures in rooms are achieved by understanding the physics of the heating system and the building. The whole is a heated envelope, not several separate ones — even if you completely turn off heating in one room, it will still be warmed from the neighboring rooms. So in the end, you basically don’t save anything; you just shift the demand. Even though, for calculation purposes, the rooms are considered separately.
The Energy Reference Ratio (ERR) is a politically motivated concept and has its justification with radiators and other fast-acting heating systems. However, with low-temperature underfloor heating, the ERR hardly has any impact and is as unnecessary as a goiter. Here, I recommend reading about the “self-regulating effect.” Feel free to ask in the forum who has an ERR and whether they constantly adjust the thermostats or if once set, they have never been touched again.
Furthermore, you can simply adjust temperatures via the heat carrier flow at the heating circuit valve (HKV) – the hydraulic fine balancing. This is done during the first or second heating season. After that, you generally don’t need to adjust the system again. However, keep in mind that large temperature differences are not possible in a modern house (without permanently opening windows). Typically, you can achieve a 2 to 3°C (4 to 5°F) difference between rooms. With a mechanical ventilation system with heat recovery, it’s even less, as it constantly exchanges and distributes air between the rooms.
opalau schrieb:
We have been living in a rental apartment with a central ventilation system for 5 years.The issue is usually with the system itself. To save money, it is often significantly undersized, resulting in a small 100mm (4 inch) diffuser connected to one or two 75mm (3 inch) ducts in a two-person bedroom. Before the required air volumes reach the room, users have already turned down the central unit out of frustration to avoid the airflow noise. The system’s effectiveness equals zero.
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