Hello everyone,
we are currently planning our house. One of the first questions from suppliers is always about the "heating method."
So far, I have mostly shrugged and said "gas heating."
Over the weekend, one supplier recommended air-to-water heat pumps. Until now, I didn’t even know such systems existed.
I’m trying to educate myself a bit and found the following model from the company "Stiebel Eltron":
WPL 13-23 cool
The description says it can be used for both heating and cooling.
Now my question:
Can the cooling function be understood like an "active" air conditioning system (performance of a split air conditioner), or is it more of a kind of "pseudo cooling" that lowers the building temperature from 35°C to 34.5°C (95°F to 94°F), meaning almost no real cooling?
What do you think of this technology in general? (I have only lived in houses/apartments with gas heating so far)
(Warm in winter with gas, cool in summer with a separate air conditioner)
I want it to be warm in winter (without having to wear a thick sweater indoors) and cool/cold in summer.
Until now, I have never really looked into energy efficiency.
In winter, I prefer a (very) "warm house" and rather pay extra than be cold and get 100 euros back.
With friends and acquaintances who have installed "new" technology, I often get the feeling their house is (too) cold in winter. (You don’t freeze, but it’s not comfortably warm either.)
When they visit us, they almost always say, "Oh, it’s so nice and warm here."
Best regards
Bubb
we are currently planning our house. One of the first questions from suppliers is always about the "heating method."
So far, I have mostly shrugged and said "gas heating."
Over the weekend, one supplier recommended air-to-water heat pumps. Until now, I didn’t even know such systems existed.
I’m trying to educate myself a bit and found the following model from the company "Stiebel Eltron":
WPL 13-23 cool
The description says it can be used for both heating and cooling.
Now my question:
Can the cooling function be understood like an "active" air conditioning system (performance of a split air conditioner), or is it more of a kind of "pseudo cooling" that lowers the building temperature from 35°C to 34.5°C (95°F to 94°F), meaning almost no real cooling?
What do you think of this technology in general? (I have only lived in houses/apartments with gas heating so far)
(Warm in winter with gas, cool in summer with a separate air conditioner)
I want it to be warm in winter (without having to wear a thick sweater indoors) and cool/cold in summer.
Until now, I have never really looked into energy efficiency.
In winter, I prefer a (very) "warm house" and rather pay extra than be cold and get 100 euros back.
With friends and acquaintances who have installed "new" technology, I often get the feeling their house is (too) cold in winter. (You don’t freeze, but it’s not comfortably warm either.)
When they visit us, they almost always say, "Oh, it’s so nice and warm here."
Best regards
Bubb
Hello,
With gas, the option to "cool" is missing, and mostly, an often uneconomical solar thermal system for single-family homes has to be "purchased" as well, unless alternative measures (renewable energy law) are planned.
With a heat pump, including air-source heat pumps, for example, KfW 55 standard can be achieved even without a solar thermal system. The additional repayment bonus is also quite attractive.
Best regards.
Bubb schrieb:If you skip a precise planning/calculation, then there is a high probability of that.
...Does this mean it’s a gamble?
Bubb schrieb:You can achieve sufficient warmth with any heat generator, provided the system is properly designed.
... I’d rather stick with gas, and the house is definitely warm.
With gas, the option to "cool" is missing, and mostly, an often uneconomical solar thermal system for single-family homes has to be "purchased" as well, unless alternative measures (renewable energy law) are planned.
With a heat pump, including air-source heat pumps, for example, KfW 55 standard can be achieved even without a solar thermal system. The additional repayment bonus is also quite attractive.
Best regards.
Hello Bubb,
slightly oversizing is not a problem; the heat pump adjusts its output down automatically! This means it operates under partial load. The reason I prefer three-phase units is because their lifespan is much longer compared to single-phase units. The smallest three-phase heat pump has 11.2 kW (13.4 hp), but as mentioned, you can set it to partial load mode where it runs even quieter and more efficiently. I don’t see any disadvantages here.
A supply temperature of 28°C (82°F) is completely normal for new buildings; they are very well insulated from below, and heat naturally moves downward. You just need to lay the pipes very close together, and then it works well.
As I said, many of my colleagues have done it this way, and everyone is satisfied.
slightly oversizing is not a problem; the heat pump adjusts its output down automatically! This means it operates under partial load. The reason I prefer three-phase units is because their lifespan is much longer compared to single-phase units. The smallest three-phase heat pump has 11.2 kW (13.4 hp), but as mentioned, you can set it to partial load mode where it runs even quieter and more efficiently. I don’t see any disadvantages here.
A supply temperature of 28°C (82°F) is completely normal for new buildings; they are very well insulated from below, and heat naturally moves downward. You just need to lay the pipes very close together, and then it works well.
As I said, many of my colleagues have done it this way, and everyone is satisfied.
Has anyone had long-term experience with an air-to-water heat pump? I mean more than one year, and can share information about the electricity costs?
My builder claims that the monthly costs are lower compared to a gas condensing boiler.
I'm a bit skeptical because air-to-water heat pumps perform worse in colder outdoor temperatures. On cold days, electric heating rods must be used to supplement heating.
The builder claims that the average monthly cost over the year is only €50 (KfW70 standard and 120cm² (1,292 square feet) semi-detached house) and that a gas condensing boiler would cost about €70 with the same consumption.
Do you think this is accurate? Then for me, the air-to-water heat pump would be the better option. I would also save the gas connection.
My builder claims that the monthly costs are lower compared to a gas condensing boiler.
I'm a bit skeptical because air-to-water heat pumps perform worse in colder outdoor temperatures. On cold days, electric heating rods must be used to supplement heating.
The builder claims that the average monthly cost over the year is only €50 (KfW70 standard and 120cm² (1,292 square feet) semi-detached house) and that a gas condensing boiler would cost about €70 with the same consumption.
Do you think this is accurate? Then for me, the air-to-water heat pump would be the better option. I would also save the gas connection.
Hello,
In other words, any answer would be wrong!
If you want to save, you must first invest in proper, unbiased expert advice and planning. Otherwise, only one party profits—and this will most likely be the general contractor!
Best regards
Wallace schrieb:The question is quite odd! It’s comparable to: Which car is more efficient, the red one or the green one.
So more than 1 year and can say something about the electricity costs?
In other words, any answer would be wrong!
Wallace schrieb:Anyone can make claims like that. It’s probably not a developer but a general contractor instead!
...My developer claims that the monthly costs are lower than with a gas condensing boiler.
Wallace schrieb:This can be, but does not have to be a disadvantage! It depends on the control curve and the bivalence point. With well-designed systems, the pure use of the electric heating rods accounts for only about 0.8...2% of the annual heating load, depending on the climate location. Usually, general contractor systems are poorly or not planned at all, and then the heating rods can become a nightmare.
...I’m a bit skeptical because air-to-water heat pumps work less efficiently at colder outdoor temperatures. On cold days, electric heating rods must be used to provide additional heating.
Wallace schrieb:I would send the "developer" packing because they clearly don’t understand building services engineering at all. At best, the demand can be the same, but the consumption is always higher with conventional heat generators and lower with heat pumps. But be careful: Here, kWh are meant, not €!
...The developer claims that the average monthly cost over the year is only 50€ (KfW70 and 120m² (1300 sq ft) semi-detached house) and that a gas condensing boiler would cost about 70€ at the same consumption.
Wallace schrieb:
...I would save even more then.
If you want to save, you must first invest in proper, unbiased expert advice and planning. Otherwise, only one party profits—and this will most likely be the general contractor!
Best regards
Hello Wallace,
Good air source heat pumps already have a good efficiency at lower temperatures. Take a look at the Mitsubishi Zubadan, the air source heat pump heats at -25°C (-13°F) without an electric heating element; it isn’t even connected in the heat pump.
And 50€ per month (average) is realistic. I would only advise not to give up on having a stove.
This year we are building 130 m² (1400 sq ft) of living space, also to KfW 70 standard. According to my calculations, I shouldn’t exceed 50€. You just need to design the underfloor heating with the lowest possible supply temperature (around 28-32°C (82-90°F)), then the efficiency will be even higher.
Regards
Max
Good air source heat pumps already have a good efficiency at lower temperatures. Take a look at the Mitsubishi Zubadan, the air source heat pump heats at -25°C (-13°F) without an electric heating element; it isn’t even connected in the heat pump.
And 50€ per month (average) is realistic. I would only advise not to give up on having a stove.
This year we are building 130 m² (1400 sq ft) of living space, also to KfW 70 standard. According to my calculations, I shouldn’t exceed 50€. You just need to design the underfloor heating with the lowest possible supply temperature (around 28-32°C (82-90°F)), then the efficiency will be even higher.
Regards
Max
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