Hello everyone.
As a first-time homebuyer, I have many questions. One that has been on my mind lately is this:
We have a KfW70 house with good insulation (16cm (6 inches) masonry and 18cm (7 inches) insulation), and underfloor heating powered by a ground source heat pump.
When I drop my little one off at kindergarten in the morning, I am always surprised that the tiles in the kindergarten’s entrance area feel noticeably warm.
Our tiles, for example in the living room, on the other hand, feel noticeably cold. The thermostat in the living room is set to 20°C (68°F), and it maintains that temperature well, which is good. But why do the tiles feel cold to the touch?
Is it because the kindergarten is not heated with geothermal energy and, on the other hand, is not insulated like our house?
Of course, the underfloor heating is meant to maintain the room temperature (which it does) and not to warm your feet. But what explains the "noticeably cold tiles" anyway? Our heating system obviously doesn’t have to work as hard because of the good insulation.
An explanation would definitely help me feel more at ease.
As a first-time homebuyer, I have many questions. One that has been on my mind lately is this:
We have a KfW70 house with good insulation (16cm (6 inches) masonry and 18cm (7 inches) insulation), and underfloor heating powered by a ground source heat pump.
When I drop my little one off at kindergarten in the morning, I am always surprised that the tiles in the kindergarten’s entrance area feel noticeably warm.
Our tiles, for example in the living room, on the other hand, feel noticeably cold. The thermostat in the living room is set to 20°C (68°F), and it maintains that temperature well, which is good. But why do the tiles feel cold to the touch?
Is it because the kindergarten is not heated with geothermal energy and, on the other hand, is not insulated like our house?
Of course, the underfloor heating is meant to maintain the room temperature (which it does) and not to warm your feet. But what explains the "noticeably cold tiles" anyway? Our heating system obviously doesn’t have to work as hard because of the good insulation.
An explanation would definitely help me feel more at ease.
N
nordanney20 Nov 2014 15:27With a supply temperature of 25/26 degrees Celsius (77/79°F) and the current weather (you also live in NRW, where it is still quite mild at the moment), the room temperature MUST reach above 18 degrees Celsius (64°F). Maybe the temperature isn’t reaching the heating circuits because a valve is closed somewhere. Your floor should also feel comfortably warm. We notice a significant difference on tiles between the tiles on the stairs/landings and, for example, the tiles in the kitchen. Is it the same for you?
C
crazy517020 Nov 2014 15:32We don’t even want to start with the flooring. The living room on the ground floor has tiles, which feel cold. The first floor has laminate flooring, which also feels cold to the touch. According to the plumber and the developer, this is correct because the insulation of the house is, in quotation marks, excellent, so the warmth shouldn’t be noticeable. Mild climate is a relative term. Right now, we have 7°C (45°F).
N
nordanney20 Nov 2014 16:00crazy5170 schrieb:
We don’t even want to start with the flooring. The ground floor living room has tiles that feel cold. The first floor has laminate, which also feels cold. According to the plumbing and the developer, this is correct because the insulation of the house is supposedly top quality, so the warmth shouldn’t be noticeable. Mild climate is relative. We currently have 7°C (45°F) If the tiles in your place feel cold, then the heating’s warmth probably isn’t reaching them (just a practical layman’s opinion). There’s definitely a noticeable difference between “tiles without underfloor heating” and “tiles with underfloor heating” in terms of the supply temperature. Have your heating technician come by; otherwise, you won’t get any further.
P.S. Definitely mild for mid to late November. Here we have similarly “warm” 7–8°C (45–46°F) (Lower Rhine region).
We do not notice the heated areas on the tiles (not cold, but also not warm), but we do notice the unheated areas (uncomfortably cold), for example, tiles in the utility room or under the stairs.
Do all rooms have the problem of not getting warm, or only the living room and bathroom?
Does the heating circuit pump run at some point? If yes, what are the supply and return temperatures when it is running?
Are the valves on the heating circuit manifold fully open?
Is there still pressure in the heating circuit, or could there be a leak?
Are domestic hot water times set?
Is there a manual available?
What adjustment options are available for the heating curve?
My personal guess is that the target room temperature of 35°C (95°F) somehow shifts your heating curve so that the heating does not work properly, or as nordanney mentioned, the valves are not fully open.
Source bosy-online.de
What can be adjusted (how is the heating curve defined)?
The heating curve varies depending on the manufacturer and/or controller.
The simplest heating curve is a straight line defined by at least two points, for example, a supply temperature of 40°C (104°F) at an outdoor temperature of +10°C (50°F), and 60°C (140°F) at an outdoor temperature of -10°C (14°F), with the other values linear between these points.
However, most heating curves are somewhat curved to realistically represent the heat output of radiators or underfloor heating.
With many heating curves, only two values can be set, usually the slope (or gradient) and the target room temperature, or the slope and a parallel shift (offset), or the slope and the starting point (curve origin).
For some manufacturers/controllers, the heating curve is defined by three parameters: slope, offset, and target room temperature. The slope determines the steepness of the curve, the offset shifts the entire curve vertically up or down, and changing the target room temperature shifts the entire curve along a slanted line representing room temperature. See the first three graphics illustrating the heating curve shifting with a slope of 7.5 (manufacturer-specific) after increasing or decreasing the target room temperature by 5°C (9°F).
The slope or steepness of the heating curve defines how much the supply temperature should change depending on the outdoor temperature (see figure 4). Possible slopes vary greatly by manufacturer; many controllers use slopes between 0.1 and about 3.5. For underfloor heating, the slope tends to be flatter, around 0.5, while for radiators, the curve is steeper, for example 1.3. The poorer the building’s insulation, the steeper the heating curve usually needs to be.
The offset shifts the entire heating curve vertically up or down (see figure 5). This can be used, for example, to compensate for inaccurate temperature sensor readings or to generally adjust the heating curve if the indoor temperature is consistently too warm or too cold at all outdoor temperatures.
Do all rooms have the problem of not getting warm, or only the living room and bathroom?
Does the heating circuit pump run at some point? If yes, what are the supply and return temperatures when it is running?
Are the valves on the heating circuit manifold fully open?
Is there still pressure in the heating circuit, or could there be a leak?
Are domestic hot water times set?
Is there a manual available?
What adjustment options are available for the heating curve?
My personal guess is that the target room temperature of 35°C (95°F) somehow shifts your heating curve so that the heating does not work properly, or as nordanney mentioned, the valves are not fully open.
Source bosy-online.de
What can be adjusted (how is the heating curve defined)?
The heating curve varies depending on the manufacturer and/or controller.
The simplest heating curve is a straight line defined by at least two points, for example, a supply temperature of 40°C (104°F) at an outdoor temperature of +10°C (50°F), and 60°C (140°F) at an outdoor temperature of -10°C (14°F), with the other values linear between these points.
However, most heating curves are somewhat curved to realistically represent the heat output of radiators or underfloor heating.
With many heating curves, only two values can be set, usually the slope (or gradient) and the target room temperature, or the slope and a parallel shift (offset), or the slope and the starting point (curve origin).
For some manufacturers/controllers, the heating curve is defined by three parameters: slope, offset, and target room temperature. The slope determines the steepness of the curve, the offset shifts the entire curve vertically up or down, and changing the target room temperature shifts the entire curve along a slanted line representing room temperature. See the first three graphics illustrating the heating curve shifting with a slope of 7.5 (manufacturer-specific) after increasing or decreasing the target room temperature by 5°C (9°F).
The slope or steepness of the heating curve defines how much the supply temperature should change depending on the outdoor temperature (see figure 4). Possible slopes vary greatly by manufacturer; many controllers use slopes between 0.1 and about 3.5. For underfloor heating, the slope tends to be flatter, around 0.5, while for radiators, the curve is steeper, for example 1.3. The poorer the building’s insulation, the steeper the heating curve usually needs to be.
The offset shifts the entire heating curve vertically up or down (see figure 5). This can be used, for example, to compensate for inaccurate temperature sensor readings or to generally adjust the heating curve if the indoor temperature is consistently too warm or too cold at all outdoor temperatures.
N
nordanney20 Nov 2014 16:14Musketier schrieb:
On the tiles, we don’t notice the spots that are heated (not cold, but not warm either), but we do notice the areas that are unheated (unpleasantly cold), for example, tiles in the utility room or under the stairs. That’s exactly what I mean
crazy5170 schrieb:
We don’t even want to start talking about the floor. The living room on the ground floor has tiles, which feel cold. The first floor has laminate, which also feels cold to the touch. According to the plumber and the builder, this is normal because the insulation of the house is “top quality,” so the warmth shouldn’t really be felt. Mild climate is relative. Right now, it’s 7°C (45°F).According to the construction companies, every newly built house nowadays has top-quality insulation. That’s just how houses are built today.
I’m not very familiar with geothermal systems, but we have underfloor heating with our gas boiler.
Where the valves are installed, the floors feel nicely warm to the feet—even now, with mild 7°C (45°F) outdoor temperatures. After all, the heating system needs to provide your comfort temperature inside the house. This warmth is transferred into the room through the tiles.
That’s why, as @Musketier and @nordanney say: at 7°C (45°F) outside, you should definitely feel some warmth at your feet.
Check the floor temperature around the valves (even better if you know where the pipes are laid): if it feels cold underfoot there, call the plumber! Then something is not set correctly. I suspect the valves are not opened—the tiler must close them before laying the tiles to prevent the screed from getting too warm.
Regards, Yvonne
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