Hello,
My husband and I are currently trying to decide which heating system to install in our planned house.
I insist on having a ventilation system and a wood-burning stove in the living room. So the heating should be compatible with these.
Our chosen construction company has now offered us three heat pumps:
Air-to-water heat pump: Nibe F2040-8 with Nibe VVM320
Exhaust air heat pump: Nibe F750 P with supply air module SAM 40
Ground source heat pump: Nibe 1245-6 with deep drilling
My husband currently prefers the exhaust air heat pump because he thinks it works like the air-to-water heat pump but makes better use of the warm air from running computers... Everywhere I read, though, it says: "Avoid exhaust air heat pumps unless you are building a passive house."
Does the supply air module actually make it function somewhat like an air-to-water heat pump, but with better use of the warm indoor air?
The house is planned as a two-story timber frame construction with KfW 55 standard. To be honest, I am completely overwhelmed by this complicated heating topic. The more information I get, the more complex it seems.
My husband and I are currently trying to decide which heating system to install in our planned house.
I insist on having a ventilation system and a wood-burning stove in the living room. So the heating should be compatible with these.
Our chosen construction company has now offered us three heat pumps:
Air-to-water heat pump: Nibe F2040-8 with Nibe VVM320
Exhaust air heat pump: Nibe F750 P with supply air module SAM 40
Ground source heat pump: Nibe 1245-6 with deep drilling
My husband currently prefers the exhaust air heat pump because he thinks it works like the air-to-water heat pump but makes better use of the warm air from running computers... Everywhere I read, though, it says: "Avoid exhaust air heat pumps unless you are building a passive house."
Does the supply air module actually make it function somewhat like an air-to-water heat pump, but with better use of the warm indoor air?
The house is planned as a two-story timber frame construction with KfW 55 standard. To be honest, I am completely overwhelmed by this complicated heating topic. The more information I get, the more complex it seems.
G
Goldi0911118 Aug 2016 10:18@Gym, could you please share your calculation with me?
Goldi, I don’t think I saved it. You first need to estimate your heating demand, which depends on certain key values based on the insulation standard. Then, estimate the hot water demand, which is independent of the insulation standard.
After that, search online for a seasonal performance factor calculator.
For example, suppose you have 7,000 kWh (23,800,000 BTU) for heating and 3,000 kWh (10,200,000 BTU) for hot water. The hot water share is 30%.
You divide the total by the seasonal performance factor for an air-to-water heat pump and a ground-source heat pump. The difference is your annual kWh difference. Multiply this by the heat pump electricity rate from your utility provider.
In this example, using 3.8 for the air-to-water heat pump and 4.7 for the ground-source heat pump, the difference is 500 kWh (1,700,000 BTU). At 20 cents per kWh on the heat pump tariff, this equals 100 USD per year.
After that, search online for a seasonal performance factor calculator.
For example, suppose you have 7,000 kWh (23,800,000 BTU) for heating and 3,000 kWh (10,200,000 BTU) for hot water. The hot water share is 30%.
You divide the total by the seasonal performance factor for an air-to-water heat pump and a ground-source heat pump. The difference is your annual kWh difference. Multiply this by the heat pump electricity rate from your utility provider.
In this example, using 3.8 for the air-to-water heat pump and 4.7 for the ground-source heat pump, the difference is 500 kWh (1,700,000 BTU). At 20 cents per kWh on the heat pump tariff, this equals 100 USD per year.
A new air-to-water heat pump with an annual performance factor of 3.8 is, in my opinion, quite optimistic. This year, there were several months here with an average temperature around zero degrees Celsius (32°F), and the COP is usually significantly lower in those conditions.
from on the go
from on the go
Oh, so the figures from the annual performance factor calculator are too good for air-to-water heat pumps but too poor for ground-source heat pumps? Interesting.
In another forum, people easily achieve values above 4 with the Panasonic. The better the insulation, the higher the proportion of hot water. This demand exists year-round, even in summer at 25°C (77°F) outside temperature and 5°C (41°F) ground temperature.
The differences in energy consumption are marginal, especially with good insulation.
In another forum, people easily achieve values above 4 with the Panasonic. The better the insulation, the higher the proportion of hot water. This demand exists year-round, even in summer at 25°C (77°F) outside temperature and 5°C (41°F) ground temperature.
The differences in energy consumption are marginal, especially with good insulation.
S
Sebastian7918 Aug 2016 13:06No way at all, and not everyone has such optimized heat pumps—let alone considering the installation location.
In winter, these units simply don’t perform well—people tend to think short term and say, “Winter? That’s over already.”
But the average temperature shows that winter is definitely still here, and then you end up with your air-source heat pump watching the meter spin.
This is always dismissed... not to mention the noise, which can be audible depending on the building environment.
By the way, the ground temperature is higher than 5 degrees Celsius (41°F).
In winter, these units simply don’t perform well—people tend to think short term and say, “Winter? That’s over already.”
But the average temperature shows that winter is definitely still here, and then you end up with your air-source heat pump watching the meter spin.
This is always dismissed... not to mention the noise, which can be audible depending on the building environment.
By the way, the ground temperature is higher than 5 degrees Celsius (41°F).
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