Recirculating Inside Air Only

[kitjv]

I have a Nest Learning Thermostat. I live in an area that is currently inundated with wildfire smoke. If I run the AC, obviously the smokey outside air will be drawn into the house. I read a post on this forum which says that if the G-wire is connected, I can run the fan only without the AC or heat. However, I assume that the fan is located in the AC unit. Although the AC itself does not kick on, the fan is running, thereby pulling in outside smoke.

So, how is it possible to recirculated the air inside the house? Thank you for any help. Much appreciated.

[kitjv]

Sorry if I sound a bit impatient, but I am really hoping to get a response to my original post above. It doesn't look like the wildfire smoke is going to let up soon. Thank you.

[zoeuvre]

Hi kitjv, 

Thanks for posting, and I'm sorry for the delayed response. I understand your concern about running the fan on your Nest Learning Thermostat during times of wildfire smoke. While the fan is typically located in the HVAC system, here are a few options you can consider to help minimize the intake of outside air and recirculate the air inside your home:

1. Ensure that all windows and exterior doors are tightly closed to prevent outside air, including smoke, from entering your home as much as possible.
2. Consider using portable air purifiers with high-efficiency particulate air (HEPA) filters in the rooms where you spend the most time. These devices can help filter out airborne particles, including smoke, and improve the air quality indoors.
3. If you have a G-wire connected to your Nest thermostat, you can run the fan in "circulate" mode without activating the AC or heat. This mode allows the fan to run intermittently, helping to mix the air inside your home without drawing in as much outside air. However, keep in mind that this may still bring in some smoke if it is present outside. You can enable the "circulate" mode through the Nest app or directly on the thermostat itself.
4. Some HVAC systems have settings that allow you to manually control the fan speed or adjust the fan operation. HVAC systems can be adjusted to minimize smoke intrusion by adjusting fan speed, limiting outside air intake, using recirculation mode, upgrading air filters with higher MERV ratings, and sealing air leaks around windows, doors, vents, and other areas. You can always contact a local HVAC professional to get help with filter sizes and types.

On the other hand, prioritize health and safety during heavy smoke periods, seek alternative shelter or clean air spaces, and consult local authorities and health organizations for recommended actions. Learn more about these here on the air filters and filter reminders guide. 

Let us know if you have any other questions.

Best,

Zoe