HVAC UV-C Air System Sanitization

Friday, May 28, 2020

HVAC UV-C Air System Sanitization

I've nearly finished installing a powerful UV sanitizing light in my HVAC system. After I had ordered it I did some investigating. A light this powerful is used to kill pond scum in a pond about ten yards long and ten yards wide and ten feet deep. So it will definitely kill everything in the air system of my home.

Here is the unit I ordered from Amazon.

OdorStop Air Treatment System OS72

I found a relay unit that triggers from 24 VAC and switches 110 VAC. The relay is used to automatically switch the light on when the HVAC blower starts running and turn it off when the blower stops.

For convenience I am using the signal to the humidifier to trigger the relay.

The light unit is designed to run 24x7. It seems to be a waste of watts to have the light burning when the blower isn't running. So I added the switching relay to turn it on when the humidifier water solenoid opens. I may try to switch that. I need to figure out where the signal is that turns on the squirrel cage blower.

IoT Relay

Here is the installation:

There was a dangerous light leak that I had to seal. You can see the shiny tape where the round duct goes into the other duct.

 

I couldn't seal this one. The glow of light is indirect. I checked to make sure it wasn't too bright. I won't look at it. I can glance at it and use it as a convenient indicator that the light is working. The light in there must be blinding.

You can look up the OdorStop on Amazon and watch the video. I wonder if this kills pollen. I know it definitely kills viruses, germs, and fungus.

Now that I know how everything works, if I had to do it again I would get two powerful LED UV screw in bulbs from AliExpress. They cost from $25 to $50 each and last forever. I think they also use about 1/7 the amount of electricity for the same amount of light. I would put them in sockets attached to a plate that bolts into the air duct in about the same way. I would also get a simple solid state switching relay there. It costs about $5. I may do that anyway. These quartz tubes cost about $10 each and should be replaced every year or two.

I hope everyone around you is safe and untouched by the virus. A neighbor is an emergency room doctor. Both she and her husband stayed home for about 8 weeks. I assume they both got COVID-19. This suburban county has about 1,000,000 people. About 10,000 people have caught the disease so far. Right now there are about 1,000 new cases every day. 243 people have died. Having only 1% cases and 0.25% deaths of cases is fairly good. But it could be much lower if our leaders took it seriously. If I get it, depending on how my health is calculated, I have either a 5% or a 25% chance of dying. For me, that is an excellent reason to sanitize the air.