Best location for HRV

jb9

Hello,

I am designing a 2 story house (~1500 sq.ft.) and will need an HRV to supplement my tight building envelope. I have attached two jpgs that show where I am considering locating the HRV unit. I am fairly certain I will put it in the basement due to noise concerns (bedrooms are on the 2nd floor). I know I need to keep it away from the carport but other than that, I am interested in what informs the decision of locating these units. I have indicated the direction of the prevailing winds (West Southwest) as well.

Thanks.

unclejohn

You are over thinking this. Put it where you have the shortest duct run.

BillW

You have indicated that you are installing a HEAT recovery ventilator as opposed to an ENERGY recovery ventilator. HEAT recovery ventilators must be in a space where they won't be exposed to freezing temperatures. They have a defrost cycle, and a drain must be provided for the water to drain away. You are correct to place the unit intake away from the garage or driveway, but be mindful of other odor sources like garbage cans, pet areas, dryer and heating equipment exhausts and kitchen fan exhausts. Install a bird screen. The shortest ductwork is the best, and insulate it. You can control the HRV from a thermostat with the HRV option, a manual control, a dehumidistat or a timer. Typical practice is for the unit to run 24/7 on low speed, with the option to go to a higher speed when people are cooking, smoking or taking showers. HRV's tend to dry out a space, but they are NOT de-humidifiers. They may be ducted into your duct system, or you can install seperate ductwork. On extremely cold days, the discharge from them can be chilly, so you should locate the discharges high on the wall, or install a small electric re-heat (coil) in the ductwork to temper the incoming air. Typical HRV's are only about 80% efficient. Finally, be careful that you do not pressurize or de-pressurize your house. Either can cause major problems. Good luck.

jb9

Thanks BillW. Sorry for the slow response. I found some documentation on some of the Lennox models and it echoes a lot of the recommendations you made. Also, it did recommend "locating the unit upstream (if there are prevailing winds)." Not sure what this means... If prevailing winds come from the southwest, does that imply the southwest corner is a good place for the unit? Any thoughts?

Also, can anyone recommend any other brands besides Lennox?

BillW

I am not aware of any restrictions involving prevailing winds although a strong wind blowing directly into the intake could possibly force hot or cold outside air thru the system. Most of the major hvac manufacturers offer ER/HR ventilators: Trane, Carrier, Lennox, Honeywell and others.