Any expereinces with Single Room Heat Recovery?

[RFw3Duwrd7Yu]

I'm renovating a drafty old house (draughtproofing, interior wall insulation, new windows, etc.) and installing an ASHP to run radiators. I'm now looking towards the kitchen more specifically. I'm aware of the need to have good ventilation and air exchange in the kitchen, but am reluctant to lose all that heat out an air vent. Wondering what experiences folks have had with single room heat recovery devices (like here: https://www.kair.co.uk/product/kair-heat-recovery-room-ventilator/).

Has anyone installed one of these? Found them to make a reasonable difference?

 

[stem]

I installed one for a friend in his wetroom. It worked well and kept the room fresh and dry. It ran on trickle permanently and switched to boost automatically when he showered and the humidity rose, returning to trickle when the humidity dropped. The air being blown outside felt slightly warm, but certainly not as warm as the air inside the house, so from that I figured it was recovering much of the heat.

However the device you refer to has a low airflow rate of 19m3 & 38m3 / hour is designed to be left operating continually. In a kitchen, a much greater extraction rate is usually required when cooking. Most cooker hoods & chimneys for example have an extraction rate of 300m3 to 400m3 / hour; ten times more than the unit you refer to, so I don't think it would work particularly well in a kitchen as the main source of extraction.

You might be able to find a separate heat exchanger you could connect to a traditional hood / chimney that has a suitable capacity. The advantage here would be that when the weather is warm, the intake fan could be switched off and the heat not returned to the kitchen.

My first home 30 years ago was a tiny, electrically heated, 3 room property. Conscious of running costs, I fitted a REGA whole house ventilation system of (I think) about 250m3 / hour with heat recovery, and I could switch off the air return fan in the summer. It worked quite well, but I didn't do much cooking!

 

[RFw3Duwrd7Yu]

Thanks for this @stem - really helpful info. I'm currently thinking I'll install a traditional hood over the range but only use this in exceptional circumstances and otherwise keep down the dampness in the room using one of those always on Vent Axia fans. I am wondering if there are useful ways to connect the hood up to heat extraction...

 

[stem]

I had an existing cooker hood, so I removed its fan and connected it to the extraction duct of the loft mounted heat exchanger. An added advantage was that the grease filter on the hood was better than the simple washable foam pad in the standard extraction grilles that came with the REGA unit. The extraction rate was less than the hood would have been but for me (single guy in my early twenties and no chef) it was fine.