We are working on a project with Habitat and our trying to provide recommendations for ventilation. We would like to see them install a Spot ERV like Panasonic's Whisper Comfort, but the small (<1,500sf) home (4 bdr) requires just over 50cfm fresh air. The Panasonic can only provide 40cfm continuous and installing two brings the incremental cost over an air cycler strategy or supply ventilation strategy too far off budget.
Does anyone have any experience / recommendations for how to best address this situation?
We are in Climate Zone 4, in Middle Tennessee, mixed-humid.
Thanks for any information!
Buy a larger one & use a timer - trust me when I say you do not want them running 24x7, especially in a humid enviroment
Sean, help a cold-climate guy out here... what's the issue with humidity and 24/7 run-time?
The humidity inside rises to much & in small houses where the AC unit is oversized because we cant buy a small enough unit...
There are a couple of pretty nifty choices from Venmar. The Kubix unit comes in either an HRV or ERV version. It uses 60 watts, 77% Apparent Sensible Effectiveness (ASE). It's like a 16" cube using 4" ducting. A more energy efficient alternative is the EKO version. The ERV version is 73% ASE. It uses between 26 and 37 watts with flows up to 84 cfm. It doesn't require a drain in the ERV version.
These are not ceiling mounted units like the Panasonic, but I think getting the supplies and exhausts separated is a better way to go if possible.
I also work with Habitat and like yours, our houses have oversized units because of the extreme tightness, low UA numbers and limitations on ASHP systems. We use a cycle timer and motorized damper for supply air ventilation. We are also considering ERV/HRV but before choosing and ERV I would have to ask if the manufacturer can supply a certification that the latent energy (water) recovery does not include any VOC, airborne pathogens or aerosols from toilets. My request to Venmar got circled back to our sales rep who was unsure if such a certification was required.