It was time to research replacement ERVs (Energy Recovery Ventilator) after two of our units broke down in 2020. A couple of key aspects re-emerged in that process.
- The heat recovery efficiency of our Recoupaerator 200 DX was unmatched based on HVI (Home Ventilation Institute) data, which was confirmed with my own testing.
- It looked like the Recoupaerator 200 DX was the only residential ERV on the U.S. market that used an enthalpy wheel for the heat and moisture transfer.
Other residential ERVs use a static core heat exchanger, or core in short. Unlike an enthalpy wheel, the core functions on the principle of cross flow. The exhaust and fresh stream flow across each other in the core without mixing. In the process thermal energy is transferred through the core’s membranes. And if we want to get all technical, we are talking about sensible energy (heat) and latent energy (moisture).
The cores come in two shapes: square and hexagonal. And this apparently small difference has a big impact when it comes to energy recovery. A hexagonal core has more surface area and thus provides more opportunity for sensible and latent energy transfer.
A quick review of product specifications led me to conclude that an ERV with a square core would be out of the question for us, because of the rather poor energy recovery rates.
Looking at products with a hexagonal core, I was left with three available options:
- Zehnder CAQ350 ERV
- Panasonic FV-20VEC1, and
- Broan ERV200 ECM (also sold under the Venmar brand name).
To help in the decision making process, I pulled the HVI performance data for each product so that I got a good comparison.
The three hexagonal core options appeared to be all in close range of each other. Zehnder seems to be a little bit of an outlier on the net air flow side for the test data, while the Panasonic and Broan are in close range.
Looking at the power consumed in watts, it was a close race, where Broan emerged with the least power consumption.
As for the energy recovery rate – or if you prefer the technical term, the Adjusted Sensible Recovery Efficiency (ASRE), we have another close race with Zehnder squeezing into first place, closely followed by Panasonic and Broan.
These were useful data to have, but I still was left without a clear preference between the three options. So I began to look at cost. And remember, these were pre-inflation prices. Zehnder came in just above $3,000, Broan landed just under $3,000, and Panasonic just under $2,000.
It looked like I was left with two favorites in this horse race: Panasonic and Broan.
Between the two, the Broan ERV seemed to be the most compatible. It has similar dimensions to the old Recoupaerator 200 DX and as such would fit nicely into the ventilation closet. It also had very similar controls and low voltage auxiliaries, just like the Recoupaerator 200 DX.
The Panasonic also had very similar dimensions to the old Recoupaerator 200 DX and as such would fit nicely into the existing ventilation closet. But its controls seemed rather primitive, and the auxiliary controls for some reasons all required line voltage. And it was unclear what advertised auxiliary controls would actually be available.
Based on my past experience, I was not in the mood to bet all my money on one horse. Diversifying my investment seemed to be a safer path to take. So I ended up ordering one Panasonic FV-20VEC1 and one Broan ERV200 ECM to replace the two failed Recoupaerator 200 DX.