Zehnder HRV/ERV configuration
We got a quote on a HRV/ERV 550 model, we had been trying to decide whether to size down to a 350 or not but I think we’re going to stick with the 550 they recommended.
We were specced an electric in-line heater ($699) for it but my architect suggested we also consider the geothermal PEX ground loop product ($2000) they offer in the foundation to save energy at pricing delta of $1300 more than the electric resistance heater. I am not sure what the total power saving is or reliability between the two, but I do know that PV systems run around $3/W before the tax credit so they ultimately go for around $2/W installed – for the equipment pricing difference we could add two solar panels to our array around 650-700 W of capacity and have a simpler and more reliable in-line electric heater for the air rather than the geothermal pex system.
There’s significantly much less labor to install the in-line heater and the geothermal requires an expert in geothermal for installation and more maintenance for the brine lines etc – a good contractor is essential (anyone recommended in the VT area?). The labor difference we’d probably have another 350-700W of PV installed so maybe 1.4 Kw PV array providing benefits for the whole year.
Heater is 3.5 Kw micropulse on demand based on temperature (25F HRV or less 14F or less ERV) and ventilation rate. Geothermal 5-70 W in operation and runs all the time rather than micropulse. Heating degree days would affect value, this project is in North Central VT in the mountains. Also geothermal product takes moisture out in the summer but the heater does nothing then – two solar panels would generate electricity year round (a lot more in the summer)
What way should we go and why – I’m not so certain but maybe the simpler setup with 2-4 extra PV panels for the $1300 equipment cost and additional labor is the best use of our money?
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