My son and wife both have allergy/asthma conditions in the late winter/spring time.

I have a 3 year old home with a Carrier Infinity system. Total finished SQFT is 5760. Half of this is in a walk-up basement. There is only one system and I am not getting good heat/cooling in a few parts of the house due to supply ducting that is too large, return ducting that is too small and equipment that was sized to large.

I am having a zoning system installed and the return reconfigured to fix the airflow issues.

The system has an ERV installed. I do not believe it was balanced properly with a magnahelic when it was installed. I just had a blower door test done on the home and the resulting calculated air changes per day was 4.4. I just had an aircheck done and voc levels were moderate to high.

There is a lot of discussion of this forum about air cleaners, good and bad.

With my setup, as long as the ERV is functioning properly and I can keep the humidity levels low in the summertime with the DEHUM function of the infinity system, should the stale air smell be eliminated? Or would I benefit by getting a Lennox Pureair or Carrier Inifinity Air Purifier? Or should I look into a HEPA rated whole house filter that piggybacks the return flow?

I am leaning towards the Lennox because they emit no ozone but My contractor is warning against the Lennox due to quality issues in the field and believes the Carrier air purifier is a superior product, however the carrier does output minor levels of ozone.

Is the cost to operate these electronic units both in power and replacement media justified?