Fresh Air

jerryk1234

Hello!

In connection with my HVAC and appliance installation endevours, I'm thinking of installing a fresh air system. Two reasons - 1, I am genuinely a bit nervous about living in such a well sealed house. 2 - we have installed a monster firebreathing range hood, capable of 1000CFM. ( A Kobe CH03 ). Where's all that air going to come from?

Broan sells a couple of "make up air dampers" - basically a motorized flap that opens or closes a duct coming from outside. I would duct it from the side of the house to the return plenum of the downstairs furnace.

In installing the range hood, I put a pair of low-voltage wires in the wall, connecting the hidden space above the range hood to a hidden space down under the cooktop.

I figure I can do the following:

* Install a current sensor in the motor lead of the range hood.
* Install a CO2 sensor ( already have this ) that talks to my Linux server.

The Linux box would monitor the motor current of the range hood, and also the CO2 concentration in the house. If the CO2 gets high, OR the range hood motor turns on, the Linux box would command the fresh air damper to open. It would also put the HVAC system into ventilation mode, UNLESS the system was already heating or cooling.

This kind of stuff is really easy with a small computer. I'll be calling the county and ask about their permitting requirements. Maybe they'll let me do it on the permit I already pulled.

- JerryK

beenthere

Hopefully thats a 3 speed hood. Cause you don't want to pay to heat up 1,000 CFM of fresh cold air, nor to dehumidify and cool it.

jerryk1234

*** Three speeds, you bet. The lowest speed is 400 CFM, and you can hardly hear it. That's really why I agreed to such a big range hood - for the quiet low speed. Big slow fans are quieter than little hyper fans.

- JerryK

jerryk1234

Actually, it's FOUR speeds. - JerryK

beenthere

Then you only want to ever use it on low. So you only need a small amount of make up air.