Insulate internal door *and* put a cat door in?

[Garald]

There is an internal door that I want to insulate (thermally, and possibly phonically as well), as it leads to a stairwell that we cannot insulate. (It's a very tight stairwell going to the attic.) However, the space under that stair is also the planned location for the cat toilet, and I do not know whether we will succeed in herding the cat into the attic every night. Are

 

(a) insulating the door

(b) carving out a cat-door in the bottom part of the door

 

compatible goals?

[JohnMo]

Seems you may have a huge gap in the insulation called a cat flap.  Don't sound that compatible.

[Jilly]

How about putting a thick curtain up to help? Most cats would figure it out. 

[Nick Thomas]

https://www.thepetflap.com/passivhaus-pet-door/

[Radian]

42 minutes ago, Nick Thomas said:

https://www.thepetflap.com/passivhaus-pet-door/

 

"3.979 W/(m²K) is a very good result for a pet door and far outperforms all standard catflaps. A typical catflap with an acrylic flap of 2-3mm thickness has a U-value in the order of 6/6.2 W/(m²K). The lower the figure the better."

 

Ubakus gives a 3mm sheet of polycarbonate a U-value of 4.444 W/(m²K) so if a regular kitty flap was 0.2m square (0.04m²) that would be a 3.5W loss with delta T of 20^oC. The ones with a magnetic closer are pretty good at being draft free.

[Adrian Walker]

1 hour ago, Nick Thomas said:

https://www.thepetflap.com/passivhaus-pet-door/

 

I know someone that installed it on their new build and the cat won't use it at all. Just waits by the door!

[Garald]

99 pounds is a bit steep for a product that the cat might refuse. Is there an alternative?

[Garald]

2 hours ago, Radian said:

 

Ubakus gives a 3mm sheet of polycarbonate a U-value of 4.444 W/(m²K) so if a regular kitty flap was 0.2m square (0.04m²) that would be a 3.5W loss with delta T of 20^oC. The ones with a magnetic closer are pretty good at being draft free.

 

Ah, interesting. You mean, like this one?

 

https://www.amazon.com/Catwalk-W-MCD-Multi-Magnetic-Cat-Door/dp/B0016H9GK6?th=1

 

But that's a lockable one (opening for a specific cat with the right microchip or key around his or her neck). Are there simpler ones?

Edited December 7, 2022 by Garald

[Radian]

18 minutes ago, Garald said:

Ah, interesting. You mean, like this one?

 

No, I don't think so. The magnetic item in that ones description is to do with the locking system. We had one where the plastic flap had a magnetic strip around its perimeter and this firmly pulled it into the closed position. It had no lock other than a two-way barrier selector.