ᐅ Retrofitting an air conditioning system – will that affect KfW funding?
Created on: 10 Jun 2021 21:02
H
Helado
Good evening everyone,
Since October, we have been living in a prefabricated house built by Hanse Haus. We have been living here for about 5 months now and are very pleased.
However, at the moment, the indoor temperature in each room is between 26°C and 28°C (79°F and 82°F), even though it is similarly warm outside. The only way we can lower the temperature is by opening the windows at night.
We have a KFW55 standard and a Stiebel Eltron LWZ 5s Plus. Unfortunately, it does not have an active cooling function, but we have installed and activated the summer cassette in the menu settings. So far, this has not produced the desired result. The temperature remains the same.
We are now considering adding air conditioning, but we have been clearly advised that this might mean no longer meeting the KFW energy-saving regulation standards, and therefore, it might affect the eligibility for subsidies. Fortunately, it is not very hot outside at the moment, but when it reaches 35°C (95°F) outdoors, the temperature inside the house can easily rise to around 30°C (86°F), which is not exactly comfortable.
Does anyone have advice or experience with retrofitting air conditioning (in specific rooms) or with the same heating system?
Thanks & best regards
Helado
Since October, we have been living in a prefabricated house built by Hanse Haus. We have been living here for about 5 months now and are very pleased.
However, at the moment, the indoor temperature in each room is between 26°C and 28°C (79°F and 82°F), even though it is similarly warm outside. The only way we can lower the temperature is by opening the windows at night.
We have a KFW55 standard and a Stiebel Eltron LWZ 5s Plus. Unfortunately, it does not have an active cooling function, but we have installed and activated the summer cassette in the menu settings. So far, this has not produced the desired result. The temperature remains the same.
We are now considering adding air conditioning, but we have been clearly advised that this might mean no longer meeting the KFW energy-saving regulation standards, and therefore, it might affect the eligibility for subsidies. Fortunately, it is not very hot outside at the moment, but when it reaches 35°C (95°F) outdoors, the temperature inside the house can easily rise to around 30°C (86°F), which is not exactly comfortable.
Does anyone have advice or experience with retrofitting air conditioning (in specific rooms) or with the same heating system?
Thanks & best regards
Helado
AllThumbs schrieb:
I am considering where a preparation might make sense Bedroom and stairwell, or rather bedroom and living room.
AllThumbs schrieb:
and whether the mechanical ventilation system might also help distribute the cool air a bit? No, physically it can only do so to a very limited extent, and the effect is practically negligible.
A ground heat exchanger can provide some relief. Essentially, the supply air for the mechanical ventilation system is passed through a duct system buried 1 to 2 meters (3 to 6.5 feet) underground. In winter, the ground temperature is around 7°C (45°F), warming the air before it enters the building. In summer, the temperature is typically about 12°C (54°F), which cools the air slightly.
This saves some heating energy, so the heating coil in the mechanical ventilation system activates later. In summer, the supply air inside the rooms is cooler than it would be without the exchanger. The earthworks can also be done with an earthworks machine, which then requires only a little more than just the pipes. Some space is naturally needed for this, so it can be difficult to implement in a mid-terrace house.
This saves some heating energy, so the heating coil in the mechanical ventilation system activates later. In summer, the supply air inside the rooms is cooler than it would be without the exchanger. The earthworks can also be done with an earthworks machine, which then requires only a little more than just the pipes. Some space is naturally needed for this, so it can be difficult to implement in a mid-terrace house.
Mycraft schrieb:
Condensate drain at every indoor unit And of course, it needs to be directed somewhere—either outside, if possible, or connected to the regular wastewater system.
AllThumbs schrieb:
How many rooms do you have an indoor unit in? I’m thinking about where it might make sense to prepare for it and whether the controlled ventilation system might also help distribute the cool air a bit? We decided on all living spaces, but it could probably be done more lightly. Distribution of cool air by the controlled ventilation system doesn’t really work, just as controlled ventilation as such isn’t suitable for cooling.
A
AllThumbs16 Jun 2021 11:51Mycraft schrieb:
No, physically it can only do so much, or rather, the effect is practically negligible. K1300S schrieb:
We decided to equip all living spaces, but it could probably be done more lightly. Distributing cool air through the mechanical ventilation with heat recovery doesn’t really work, just as such a system is generally not suitable for cooling. Ok, I thought it would balance out similarly, since in winter, for example, there aren’t huge temperature differences between the rooms anyway.
I’m currently considering preparing the bedrooms, children’s rooms, and office. The living room is adjacent to the utility room, so something can be done there later...
AllThumbs schrieb:
there is always room for a bit more later...Sure, but keep in mind that thicker pipes need to be installed from the start.Similar topics