Hello everyone,
I wanted to ask for your opinion. In our new build, an air-to-water heat pump from Vaillant or an equivalent brand will be installed.
Since we are currently not considering air conditioning, we are thinking about using the heat pump for some cooling. Of course, it’s no comparison to a dedicated air conditioner, but at least a little cooling, right?
I would like the heat pump to operate in reverse mode to expel warm air outside. At the same time, my partner doesn’t want a “freezing cold” underfloor heating. Besides, the warm air naturally stays “up top.”
Can you still recommend something, or would you advise against this entirely?
Thanks for your help.
I wanted to ask for your opinion. In our new build, an air-to-water heat pump from Vaillant or an equivalent brand will be installed.
Since we are currently not considering air conditioning, we are thinking about using the heat pump for some cooling. Of course, it’s no comparison to a dedicated air conditioner, but at least a little cooling, right?
I would like the heat pump to operate in reverse mode to expel warm air outside. At the same time, my partner doesn’t want a “freezing cold” underfloor heating. Besides, the warm air naturally stays “up top.”
Can you still recommend something, or would you advise against this entirely?
Thanks for your help.
This seems to be an emotional topic for you. I didn’t mean to attack you, although you are of course a prime example of wasting resources, as interesting as your project is. However, I don’t understand why you’re bringing up this child argument now. It’s not my fault that you don’t have children.
This topic is not emotional for me at all.
Yes, our construction project is a total waste of resources. That’s why I don’t claim to have made sacrifices for ecological reasons. Overall, it’s lost in the background noise.
Hence the comment about building a new detached house.
I exaggerated my statement on purpose but clearly marked it with sarcasm. Whether or not I have children doesn’t matter. If it were my absolute wish, solutions could be found (artificial insemination, surrogate mother, adoption). I don’t see how I connected that to you.
I wrote generally (one should) and not specifically you.
I think you are taking it too emotionally.
It wasn’t meant as a personal attack either.
But you still haven’t explained why the temperature was only 1–2 degrees Celsius (34–36°F) in February and suddenly you can maintain 23 degrees Celsius (73°F) even during heat waves. And why temperatures over 1–2 degrees Celsius (34–36°F) are suddenly possible. Has there been a heat wave in recent months?
And that’s exactly what makes your statements seem unreliable. It is perfectly legitimate to install such a system. But one should be honest about its performance. Otherwise, it only confuses newcomers or leads to bad purchases and unmet expectations.
Yes, our construction project is a total waste of resources. That’s why I don’t claim to have made sacrifices for ecological reasons. Overall, it’s lost in the background noise.
Hence the comment about building a new detached house.
I exaggerated my statement on purpose but clearly marked it with sarcasm. Whether or not I have children doesn’t matter. If it were my absolute wish, solutions could be found (artificial insemination, surrogate mother, adoption). I don’t see how I connected that to you.
I wrote generally (one should) and not specifically you.
I think you are taking it too emotionally.
It wasn’t meant as a personal attack either.
But you still haven’t explained why the temperature was only 1–2 degrees Celsius (34–36°F) in February and suddenly you can maintain 23 degrees Celsius (73°F) even during heat waves. And why temperatures over 1–2 degrees Celsius (34–36°F) are suddenly possible. Has there been a heat wave in recent months?
And that’s exactly what makes your statements seem unreliable. It is perfectly legitimate to install such a system. But one should be honest about its performance. Otherwise, it only confuses newcomers or leads to bad purchases and unmet expectations.
rick2018 schrieb:
... and suddenly you can maintain 23 degrees even during heatwaves.Your problem is that you only read parts and take isolated quotes. 23 degrees... Yes, cooling, shading, insulation... many factors play a role, cooling is just one component. The overall concept has to work. How much cooling actually contributes... I estimate around 2 degrees. Can I prove it? No, just like you can’t. There are analyses on this topic in the other forum... the effect is larger there.
An example... You should have read this in the other thread as well, if you had read everything: If the house heats up during a vacation and you turn on the cooling a few days before returning, you can lower the temperature by several degrees, well above the estimated 2 degrees. Why? Because the temperature difference between the ground loop and the indoor temperature is greater. Once the indoor temperature has stabilized around 23 degrees, the delta between ground loop and indoor temperature naturally becomes smaller, so the effect of cooling decreases... —> giving a fixed number of degrees is not possible.
Then we are actually not that far apart.
Of course, the effect is greater when the temperature difference is larger. Whether it is 1, 2, or 3 degrees...
However, the cooling capacity is still limited.
Feet get cold, yet it still does not dehumidify, which has the biggest impact.
The wife of the original poster (has an air-to-water heat pump) does not want cold feet.
If I did not want to install air conditioning, I would also rely on such a system...
But the limitations of the system should be explained.
Sure, if I have heavily insulated my house and the shading is down all day, I can keep the temperatures lower. At night, open the bypass in the controlled ventilation system.
You said it significantly contributes to the 23 degrees. I suspect it is actually the smallest variable.
Of course, the effect is greater when the temperature difference is larger. Whether it is 1, 2, or 3 degrees...
However, the cooling capacity is still limited.
Feet get cold, yet it still does not dehumidify, which has the biggest impact.
The wife of the original poster (has an air-to-water heat pump) does not want cold feet.
If I did not want to install air conditioning, I would also rely on such a system...
But the limitations of the system should be explained.
Sure, if I have heavily insulated my house and the shading is down all day, I can keep the temperatures lower. At night, open the bypass in the controlled ventilation system.
You said it significantly contributes to the 23 degrees. I suspect it is actually the smallest variable.
rick2018 schrieb:
Your heat pump also uses electricity when running in reverse. Normally, it would be turned off at that time or only running at maximum for hot water. In terms of cooling capacity, it is less efficient than an air conditioning unit.Well then, show me a calculation. I find that claim rather bold in the case of a ground-source heat pump. For an air-source heat pump, I’m not familiar with the electricity consumption, but I would be interested to know.
As a suggestion:
Passive cooling: about 20 to 40 W/m² (values from Mycraft in the other thread) cooling capacity. Let’s take the lower end, which for a 150 m² (1615 ft²) house equals around 2 kW cooling capacity. Electricity consumption is about 50 watts (conservative estimate, actually even less) ... ratio of 1:40 ... How does that compare to an air conditioning unit?
Edit: I had assumed ground-source heat pump all along (sorry Rick!). In the case of an air-source heat pump, I would seriously reconsider the concept… While that doesn’t change the function, it does affect the efficiency...
I was referring to the air-to-water heat pump but don’t know the exact consumption values either.
With a cooling system using a reversible heat pump, energy first has to be extracted from the ground. Only then does the actual cooling begin. It is just as slow as when heating. First, the ground and the lower air layers cool down.
This means you have to run the system for a long time or even continuously during hot periods. Especially after a vacation, you need a fairly long lead time.
A modern LG air conditioner with 2.5 kW (3.4 hp) cooling capacity has a power consumption of 700 W. Within 30 minutes to an hour, the room becomes very cold (which seems unrealistic). Additionally, the air is dehumidified.
Now let’s assume the consumption is linear, so 560 W at 2 kW (2.7 hp) cooling capacity. How many hours or days does your system have to run before the cooling effect is perceptible?
Let’s say 24 hours. That means you have already consumed 1200 watt-hours before you notice it (at your feet). With an air conditioner, you get significantly lower air temperatures and dehumidified air with 280–560 W (within half an hour to an hour).
That’s what I meant with my calculation. With an air conditioner, you can also cool more selectively.
Your point was about solar power. That also applies to the air conditioner, but it cools the house during sunlight hours. The heat pump, on the other hand, uses electricity also at night...
If you run the air conditioner continuously, it clearly consumes more than a heat pump. However, it also provides a completely different cooling effect with dehumidification.
As I said, I have nothing against the idea of a reversible heat pump.
We will also not install traditional air conditioners but a heat pump combined with a chilled water coil in the supply air. This system is also not very powerful but achieves about 10°C (18°F) (with dehumidification). That’s enough, and probably more if shading is installed downstairs, etc.
Nevertheless, a properly sized air conditioner would outperform our cooling concept.
With a cooling system using a reversible heat pump, energy first has to be extracted from the ground. Only then does the actual cooling begin. It is just as slow as when heating. First, the ground and the lower air layers cool down.
This means you have to run the system for a long time or even continuously during hot periods. Especially after a vacation, you need a fairly long lead time.
A modern LG air conditioner with 2.5 kW (3.4 hp) cooling capacity has a power consumption of 700 W. Within 30 minutes to an hour, the room becomes very cold (which seems unrealistic). Additionally, the air is dehumidified.
Now let’s assume the consumption is linear, so 560 W at 2 kW (2.7 hp) cooling capacity. How many hours or days does your system have to run before the cooling effect is perceptible?
Let’s say 24 hours. That means you have already consumed 1200 watt-hours before you notice it (at your feet). With an air conditioner, you get significantly lower air temperatures and dehumidified air with 280–560 W (within half an hour to an hour).
That’s what I meant with my calculation. With an air conditioner, you can also cool more selectively.
Your point was about solar power. That also applies to the air conditioner, but it cools the house during sunlight hours. The heat pump, on the other hand, uses electricity also at night...
If you run the air conditioner continuously, it clearly consumes more than a heat pump. However, it also provides a completely different cooling effect with dehumidification.
As I said, I have nothing against the idea of a reversible heat pump.
We will also not install traditional air conditioners but a heat pump combined with a chilled water coil in the supply air. This system is also not very powerful but achieves about 10°C (18°F) (with dehumidification). That’s enough, and probably more if shading is installed downstairs, etc.
Nevertheless, a properly sized air conditioner would outperform our cooling concept.
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