ᐅ Cat flap in KfW55 house with ventilation – any experiences?

Created on: 23 Mar 2021 09:33
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KUM_im_Tal
We have a KfW-55 end-terrace house with insulation, triple glazing, and a ventilation system. Now we want to install a cat flap in a glass panel next to the patio door. Has anyone done this before?

- How does this affect the performance of the ventilation system? It won’t be completely airtight anymore.
- How much heat loss can we expect – it’s just a simple plastic flap, after all.
- Is installation even possible with triple glazing that also has RC2 security features?

We would have a professional company do the installation, but we’re not sure if it’s all feasible. I would appreciate hearing about others’ experiences.
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Tostbert
10 Jan 2022 08:20
Badener1970 schrieb:

He really likes using the pet door now...
Hello,
I’m currently working on the same topic: a KFW 55 house and the same cat flap as yours is planned for the window.
When our house is finished, a "leakage test" (airtightness test) will have to be carried out. Was that the case for your house as well? Or was your house already completed and you installed the cat flap afterward?
Thanks in advance for your reply.
Tostbert
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Matthias45
10 Jan 2022 10:48
Tostbert schrieb:

Hello,
I’m currently working on the same topic of a KfW 55 house and want to install the same pet door in the window as you did.
When our house is finished, a “leakage test” will have to be carried out. Was that the case for you as well? Or was your house already completed and you installed it afterward?
Thanks in advance for your reply
Tostbert

The leakage test for a KfW 55 house without ventilation is basically a joke! The limit value is three air volume changes per hour.
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Tostbert
10 Jan 2022 10:56
Matthias45 schrieb:

The airtightness test for a KfW 55 house without ventilation is basically a joke! The limit is 3 air changes of the volume per hour.

We also have a ventilation system included. Do you know how the value behaves in that case?
Best regards
Tolentino10 Jan 2022 11:00
As far as I know, 1.5, passive houses 0.6.
It’s best to check with KfW directly.
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Tostbert
10 Jan 2022 11:05
Tolentino schrieb:

As far as I know, 1.5, passive houses 0.6.
But it’s best to check with the KfW.

Thank you very much for your quick replies ✌️✌️
B
Badener1970
10 Jan 2022 21:21
Tostbert schrieb:

Hello,
I’m currently dealing with the same topic of a KfW 55 house, and the same pet door as you want to install in the window.
When our house is finished, a "tightness test" (airtightness test / blower door test) must be conducted. Was this the case for you as well? Or was your house already completed and you installed it afterward?
Thanks in advance for your reply
Tostbert

During the measurement, I had sealed off the pet door.