Hello, Will be getting new kitchen cabinets installed and the new design will be blocking one of my return HRV ducts. House is open concept and I already have another return duct approx 18-20' away, and two more in other rooms on this floor which is approx 900 sqft. To re-route the duct is going to be an enormous pain, so I'm wondering if I can just block it off, allowing the other returns to feed the house, or is that going to cause me issues? thanks in advance

anyone?

system needs to be balanced - same amount of air coming in as leaving. If removing this will change that, you need to add a duct. This can be measured. Any way to just extend the duct to the top of the cabinet?

I expect that the HRV has many ducts and moving/removing one will only necessitate a minor re-balancing of the HRV. An open floor plan will have plenty of mixing.

Generally it's a good thing to exhaust air from the kitchen, because that's one of the places where humidity is put into the air. How much you care depends on your climate and cooking and dishwashing habits, among other things.

As for how well the system will still work, one thing you can do is count the returns. If this is one of only a few, you might want to add capacity. If it's one of half a dozen, that's not a big deal.

But you definitely want to rebalance, to make sure you aren't pressurizing the house with more supply than exhaust. The official way to do that is to measure each supply and exhaust flow rate, but I'd be inclined to get a manometer to measure the inside/outside pressure difference and adjust until the pressure differences is the same with the system on or off, starting by opening any exhaust dampers that aren't all the way open yet.

I like that idea. As someone pointed out, intake and exhaust temps are different, so the official way is incorrect (it should balance based on mass flow rate).

A more radical approach would be to use the HRV to adjust indoor/outdoor balance to a specified value with automatic/real-time controls.

thanks everyone for commenting. I think I will see if I can get an HRV installer come out and take a look. Like the idea of re balancing rather than relocating.