Excuse me if this has been answered, but I didn't see it in a search of the forums. We're meeting to get estimates from our HVAC installer for an HRV, and I'm wondering if the particular brand of the unit is important? If so, does anybody have a recommendations? Second, is it acceptable to have the intake and/or exhaust for this unit vented on the underside of an elevated front porch? There is about 20" of clearance between soil and the porch, and it's not enclosed on three sides. This would prevent grass/leaves/snow from entering, and hide the intake / exhaust from view. Just need to make sure its critter-proof.

I did a lot of research for my ERV about 18-24 months ago. At the time, the Ultimate Air 200DX was the most energy efficient ERV on the planet. www.UltimateAir.com Keep in mind, things may have changed, but I have not seen another ERV claiming to be more efficient.

I did purchase and install the 200DX. Regardless of the manufacturer, be sure to consider noise and vibration isolation. The unit is not loud, just louder than I expected.

You might also consider the noise of the exhaust. If you use your front porch, the white noise may irritate you. Other than that, I can't think of a reason why the intake and exhaust could not be located there.

Hope this helps.
Ed

I purchased a FanTech SHR 2005R HRV 3-speed (60,115 & 200 CFM) from EFI for $760. It claims a sensible effectiveness of 76%. Not as high as the SHR 3005R (91%), but less expensive and more compact. Whatever brand you buy, look for the following features:
1. Automatic defrost in winter
2. An aluminum heat exchanger (more durable)
3. Operational programmability
4. Override controls for bathrooms

I set up my HRV so that it injects fresh air into the HVAC duct system which is then electronically filtered before delivery to the conditioned spaces. The HVAC air handler runs continuously to ensure good distribution of the fresh air throughout the house. The HRV evacuates air from the bath and laundry rooms where the highest levels of moisture are found. Each bathroom has a manual override control to kick up the speed of the HRV to increase ventilation for 20 minutes or until manually turned off. The HRV is also activate by either of two humidistats located at opposite ends of the house. If the relative humidity rises above a programmed setpoint, the HRV operates until the desired humidity level is restored.

When the HRV kicks up to high speed (200 cfm), there is a noticeable transmission of noise through the air ducts -- much noisier than the central air handler fan. I'm not thrilled with the extra noise because it's heard everywhere in the house. I plan to insert a vibration isolation collar on the fresh air duct to cut down the noise a little. A unit which boasts lower noise levels would be worth paying a premium for.