Hello everyone,
we are building a KfW 70 house, which is economic even without a mechanical ventilation system.
Now, like many others, we are uncertain whether we really want to install a mechanical ventilation system. It has been planned, but the prices quoted are quite high... A decentralized system also seems to be similarly expensive due to the number of rooms and additionally causes quite a few holes in the nice facade...
Our heating engineer, who also installs ventilation systems, suggested installing fans in the exterior walls of the wet rooms (guest toilet and bathroom). These would be controlled by a switch and/or humidity sensors to extract the moist air from the rooms.
Additionally, a cooker hood with exhaust ventilation is recommended for the kitchen.
What do you think about this?
From a cost perspective, it does seem to be considerably cheaper.
we are building a KfW 70 house, which is economic even without a mechanical ventilation system.
Now, like many others, we are uncertain whether we really want to install a mechanical ventilation system. It has been planned, but the prices quoted are quite high... A decentralized system also seems to be similarly expensive due to the number of rooms and additionally causes quite a few holes in the nice facade...
Our heating engineer, who also installs ventilation systems, suggested installing fans in the exterior walls of the wet rooms (guest toilet and bathroom). These would be controlled by a switch and/or humidity sensors to extract the moist air from the rooms.
Additionally, a cooker hood with exhaust ventilation is recommended for the kitchen.
What do you think about this?
From a cost perspective, it does seem to be considerably cheaper.
klblb schrieb:
The energy saving regulation is not an issue. According to the energy calculation, we will have a KfW 20 house. Heated with a gas condensing boiler, which saves us from that extremely expensive heat pump stuff.That can’t be right... did you make a typo with the numbers?
@Mycraft
Well, not exactly a typo, but a bit too casually phrased. Of course, there is no KfW20 standard. I meant to say that according to the energy certificate, the house has a primary energy demand of 20% compared to the maximum value specified by the 2009 Energy Saving Ordinance. This is achieved by using passive house components, mainly a well-insulated building envelope (walls, roof, ground slab, windows). We are not using expensive ventilation systems with heat recovery, etc. Nor are we using photovoltaics or solar systems for hot water or heating. Officially and according to the energy certificate, it is therefore classified as a KfW40 house.
Well, not exactly a typo, but a bit too casually phrased. Of course, there is no KfW20 standard. I meant to say that according to the energy certificate, the house has a primary energy demand of 20% compared to the maximum value specified by the 2009 Energy Saving Ordinance. This is achieved by using passive house components, mainly a well-insulated building envelope (walls, roof, ground slab, windows). We are not using expensive ventilation systems with heat recovery, etc. Nor are we using photovoltaics or solar systems for hot water or heating. Officially and according to the energy certificate, it is therefore classified as a KfW40 house.
N
nordanney29 Nov 2013 21:11klblb schrieb:
@Mycraft
Well, not exactly a typo, but rather a somewhat casual way of expressing it. Of course, there is no KfW20 classification. What I meant to say is that the house, according to the energy certificate, uses 20% of the primary energy compared to the maximum allowed by the 2009 Energy Saving Ordinance. This is achieved by using passive house components, mainly a well-insulated building envelope (walls, roof, foundation slab, windows). We avoid expensive ventilation systems with heat recovery, etc. We also do without photovoltaic panels and solar for hot water/heating. Officially, and according to the energy certificate, it is a KfW40 house. I prefer to skip the extremely expensive insulation and instead use a heat pump (which is actually not that costly) plus a small photovoltaic system for self-consumption and controlled mechanical ventilation. Gas would be too expensive for us in the long run (since I expect gas prices to rise). Also, we cannot regularly open windows throughout the day and night to maintain a comfortable indoor climate.
Philosophies differ this way—and probably the overall costs don’t vary that much...
Well, to each their own... I chose conventional insulation and installed a central mechanical ventilation system with heat recovery. The heating system is gas combined with solar thermal.
I am assuming that electricity prices will rise, probably even faster than gas prices.
The additional costs for the mechanical ventilation system were significantly lower than those for additional insulation, etc., and the operating costs of the ventilation system are negligible. From OUR perspective, the benefit of the mechanical ventilation system compared to other measures is much higher.
But then again, I only have a KfW 70 house...
I am assuming that electricity prices will rise, probably even faster than gas prices.
The additional costs for the mechanical ventilation system were significantly lower than those for additional insulation, etc., and the operating costs of the ventilation system are negligible. From OUR perspective, the benefit of the mechanical ventilation system compared to other measures is much higher.
But then again, I only have a KfW 70 house...
N
nordanney30 Nov 2013 11:02Mycraft schrieb:
I am expecting electricity prices to rise, most likely faster than gas prices...
The additional costs for the controlled residential ventilation system were significantly lower than adding more insulation, etc., and the operating costs of the controlled residential ventilation system are simply negligible... from OUR perspective, the functional value of the controlled residential ventilation system compared to all other measures is much higher. We agree (which is also why we opted for photovoltaics)!
Hello everyone,
I’m not sure if the operating costs are really that negligible.
After all, the ducts of a mechanical ventilation system with heat recovery also need to be cleaned, right?
I read in a report that a poorly maintained mechanical ventilation system with heat recovery can become a breeding ground for germs.
Filters also need to be replaced quite frequently.
I think it's quite possible that costs of 200 to 300 euros per year (without electricity) can add up easily.
I believe you can also ensure a healthy indoor climate by choosing a wall construction that can absorb and release moisture, for example.
Best regards,
Frank
I’m not sure if the operating costs are really that negligible.
After all, the ducts of a mechanical ventilation system with heat recovery also need to be cleaned, right?
I read in a report that a poorly maintained mechanical ventilation system with heat recovery can become a breeding ground for germs.
Filters also need to be replaced quite frequently.
I think it's quite possible that costs of 200 to 300 euros per year (without electricity) can add up easily.
I believe you can also ensure a healthy indoor climate by choosing a wall construction that can absorb and release moisture, for example.
Best regards,
Frank
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