How can I prevent the fireplace smell when the A/C is on?

Question

I get the ashy fireplace smell in the family room when the A/C is running. I haven't had a fire burning in months.

I checked out this question, but it targets a recent fire and a cold air return.

It would seem that I'm getting negative pressure in the house when the A/C is running, being equalized through the fireplace. I have a Buck Stove insert that was there when we bought the house. Consequently, I don't have the standard flue closure mechanism. It's more of a stepped closure to control airflow while the stove is burning.

Is there anything I can do to prevent the negative pressure that comes with running the A/C?

Answer 1

One way would be a Heat Recovery Ventilator(HRV) that exchanges interior air for outside, which will relieve negative pressure.

Another would be a dampered (and screened) make-up air that connects to the cold air return (a low tech (and low cost) HRV). These can be tied to exhaust fans or automatic via pressure differential. You would want a HVAC firm to discuss options.

A third would be a cable operated chimney cap damper. The stove may complicate this option. I had one on a naturally aspirated fireplace and was good during rain and windy conditions that used to produce that "old fire" smell.