Any one used an HVAC Air Purifier (specifically Respicare Oxy 4)? (Houston: sales, house)

[hulio82]

Hi all!

We had our HVAC units checked out because my wife kept on insisting there's something growing in there. She said the air in the house feels off.

The HVAC company came out and took a look and definitely found some funky microbes in both of the plenums (we have 2 units). Attaching picture of one and this was the cleaner one. The other unit was even worse.

So, we're having the HVAC company clean out our units including the vents.

The HVAC sales rep is insisting we install an HVAC air purifier since given its houston and humidity levels, stuff bound to grow back in the plenums. The specific air purifier he is recommending is Respicare Oxy 4 (
https://www.respicaire.com/residenti...ifier%E2%84%A2).

I do have some concerns about chemicals these UV filters introduce in the air and just overall effectiveness in removing viruses and bacteria. My understanding is most of these work by releasing OZone, but there are ozone free options. E.g., for this specific purifier, they would have to replace the UV bulb with an Ozone free bulb which costs around $400 (per bulb) and will need to be changed out every 2-3 years.

So, my questions:
1. Anyone here have a UV air purifier installed? Thoughts on effectiveness?
2. One big concerns is smell. Lot of blogs and posts i've read online state these purifiers introduce a smell (very similar to smell in a hospital). Anyone who has installed experienced this? How bad is the smell?
3. I know Houston is pretty much a humidifier by itself, but is having bacteria growing in plenums normal? or is it due to improper installation? Event after the cleaning, if the bacteria is bound to grow back, then it makes sense to get a purifier since we have young kids in the house as well. But if this is outside the norm and as long as they install it right, we should not have bacteria growing in the unit anywhere.

Also, forgot to add - they did an indoor air inspection test and the results came out fine. So whatever is growing in there isn't making it to the air? A bit confused here.

Thanks in advance for your responses!

[WRM20]

I don't know anyone who has a purifier in their AC system, and never have. I've lived in Houston since the mid-70's. Every house has some mold in the ducts, it's a fact of life. This sounds like an upsell scheme to make money for the HVAC company.

[gwarnecke]

Having a little bit of mold in your AC ducts isn't uncommon, but a particularly high mold concentration in one part of your ductwork (or in the ductwork for one system in a multi-HVAC house) could indicate a problem that needs to be fixed vs band-aided with a UV light.

Our first house in Houston had three HVAC systems and the ducts for one of the three always had much more mold than the others. Turns out the issue was the AC return plenum wasn't properly constructed and was basically pulling in un-conditioned air from gap between the first and second floors of our house. The mold growth decreased dramatically once we repaired the plenum.

[WRM20]

Originally Posted by gwarnecke

Having a little bit of mold in your AC ducts isn't uncommon, but a particularly high mold concentration in one part of your ductwork (or in the ductwork for one system in a multi-HVAC house) could indicate a problem that needs to be fixed vs band-aided with a UV light.

Our first house in Houston had three HVAC systems and the ducts for one of the three always had much more mold than the others. Turns out the issue was the AC return plenum wasn't properly constructed and was basically pulling in un-conditioned air from gap between the first and second floors of our house. The mold growth decreased dramatically once we repaired the plenum.

That's a great point. Before spending a chunk of cash on some semi-snake oil solution for a mold problem that may not be as bad as you think, ensure the ductwork is all sealed and built correctly. If your house needs make up air from outside, there are better ways to get it than through a leaky plenum.

[utche96]

Originally Posted by gwarnecke

Having a little bit of mold in your AC ducts isn't uncommon, but a particularly high mold concentration in one part of your ductwork (or in the ductwork for one system in a multi-HVAC house) could indicate a problem that needs to be fixed vs band-aided with a UV light.

Our first house in Houston had three HVAC systems and the ducts for one of the three always had much more mold than the others. Turns out the issue was the AC return plenum wasn't properly constructed and was basically pulling in un-conditioned air from gap between the first and second floors of our house. The mold growth decreased dramatically once we repaired the plenum.

Very good advice. Most HVAC units are not properly sealed. A bucket of mastic and a roll of duct tape will go a very long way.

If you want to filter your air then I would buy a stand-alone unit from Austin Air or IQAir.