Which one is more efficient and has longer operating life, thin metal or nano paper core in a HRV?
It will be used in a Nordic country.
TL;DR
I'm searching for a heat recovery ventilator.
I am not aware of what kind of Core are they using here in north Europe, but they claim it has efficiency of up to 95%.
The ones I find at the Chinese market are "nano paper" core. They do not state the efficiency of the system.
One expert colleague of mine had heard of this in the past. Once. So it's not unknown. Another thought that it might not be that uncommon, but that it wouldn't be wise to buy one that hadn't passed a high, independent, certification standard
Amongst the experts I talked to, there was scepticism about the paper core; the heat recovery rate (75%) ascribed to it; the low expected speed of water-vapour propagation through it; and its lifetime - particularly in an environment where it would be likely to pick up grease.
Passivhaus-approved MVHRs will hit over 90% heat recovery. There are some MVHRs that have heat-exchangers which are designed to be pretty easy to remove and clean, and it might be worth considering one of these (in addition to appropriate filters). If you want the best in class, then find one certified by the Passivhaus Institut - they group them into small and large, with the threshold between the two categories being 600 cubic metres per hour.
There has been some recent attention paid to fine-wire heat exchangers in MVHR, but I don't know if there's much independent verification yet of their performance, their lifetime, and the ease of cleaning & maintaining them.
