Hello,
We are starting to get really frustrated... every builder tells us something different...
We want to build a 130sqm (1,399 sq ft) KfW 70 house with the living room facing south, and we are unsure whether to choose gas or an air source heat pump. Some providers, at almost the same price level, offer us air source heat pumps and claim that the annual costs are significantly (30%) lower compared to gas, while others doubt this.
We understand that insulation with gas/solar systems is usually better because an air source heat pump boosts efficiency more towards KfW 70 standards compared to gas/solar, which might argue in favor of gas. An air source heat pump might fail somewhat sooner, and in case of problems, you can usually get quick and competent local support with gas. With air source heat pumps, there could be more difficulties. Additionally, the noise of air source heat pumps (in our case about 3 meters (10 feet) from the neighbor) is not insignificant. Some say that sooner or later, everyone ends up having issues with neighbors for this reason.
We are interested in air source heat pumps with storage tanks from these providers: Vaillant, Mitsubishi Zubadan, and Rotex.
What we are really curious about is the annual cost for heating and hot water with both systems.
We live near Kassel.
What should we choose, and what would be cost-effective TODAY? What is your opinion on Vaillant?
Regards
Gigi
We are starting to get really frustrated... every builder tells us something different...
We want to build a 130sqm (1,399 sq ft) KfW 70 house with the living room facing south, and we are unsure whether to choose gas or an air source heat pump. Some providers, at almost the same price level, offer us air source heat pumps and claim that the annual costs are significantly (30%) lower compared to gas, while others doubt this.
We understand that insulation with gas/solar systems is usually better because an air source heat pump boosts efficiency more towards KfW 70 standards compared to gas/solar, which might argue in favor of gas. An air source heat pump might fail somewhat sooner, and in case of problems, you can usually get quick and competent local support with gas. With air source heat pumps, there could be more difficulties. Additionally, the noise of air source heat pumps (in our case about 3 meters (10 feet) from the neighbor) is not insignificant. Some say that sooner or later, everyone ends up having issues with neighbors for this reason.
We are interested in air source heat pumps with storage tanks from these providers: Vaillant, Mitsubishi Zubadan, and Rotex.
What we are really curious about is the annual cost for heating and hot water with both systems.
We live near Kassel.
What should we choose, and what would be cost-effective TODAY? What is your opinion on Vaillant?
Regards
Gigi
R
R.Hotzenplotz7 Jan 2018 15:51Is it actually correct that in a heating load calculation, cellar rooms that are not heated are also included? Even the basement corridor is listed.
We have five rooms in the cellar, of which only two are heated. However, all rooms are included in the heating load calculation, so it is based on an area of 310.2m² (3340 sq ft). Is this correct or a mistake?
We have five rooms in the cellar, of which only two are heated. However, all rooms are included in the heating load calculation, so it is based on an area of 310.2m² (3340 sq ft). Is this correct or a mistake?
R
R.Hotzenplotz7 Jan 2018 18:19Are gas/solar systems and heat pumps equally fast at reheating water? With our Nibe F 750, it takes ages for the water to warm up again after we’ve used it. It heats up the quickest when the outside temperature is below 5°C (41°F), because then the electric heating element warms it up quickly. The worst performance is at an outside temperature between about 5°C and 10°C (41°F and 50°F). Then, I estimate it takes easily 1.5 to 2 hours. I could imagine that a gas boiler might reheat water faster than a heat pump without using the electric heating element, right?
Ultimately, it depends on the device’s capacity. If the heat pump has 7 kW and the gas boiler 15 kW, the latter will probably be faster.
But it’s also a matter of the storage system. Heating a 400-liter (105-gallon) tank to shower temperature takes longer than warming an integrated one with a volume of 180 liters (47 gallons).
I’m not sure if the heating load calculation is correct. I would have thought only rooms within the heated building envelope count: Are the heated rooms insulated against the other rooms?
Just ask the author.
But it’s also a matter of the storage system. Heating a 400-liter (105-gallon) tank to shower temperature takes longer than warming an integrated one with a volume of 180 liters (47 gallons).
I’m not sure if the heating load calculation is correct. I would have thought only rooms within the heated building envelope count: Are the heated rooms insulated against the other rooms?
Just ask the author.
R
R.Hotzenplotz7 Jan 2018 18:35I just noticed in the heating load calculation that the floor plan includes underfloor heating throughout the entire basement, covering all five rooms plus the hallway. However, only two heated basement rooms were discussed and contractually agreed upon. So I am now quite certain that there is a mistake here.
Therefore, I cannot commission an energy consultant based on the current heating load calculation, nor can I make any decisions. I might end up being the one to blame if the construction is delayed because the detailed planning cannot be completed yet, but I simply cannot decide on a heating system without accurate information... really frustrating.
Therefore, I cannot commission an energy consultant based on the current heating load calculation, nor can I make any decisions. I might end up being the one to blame if the construction is delayed because the detailed planning cannot be completed yet, but I simply cannot decide on a heating system without accurate information... really frustrating.
Similar topics