Is there anything fishy here?

November 6, 2009 9:57 PM

Its that time of the year again, when I get the furnace cleaned, install a new filter, clean the humidifier ( and install a new humidifier pad), and start it all up. In the last few years, I've seen something called the "Swordfish" advertised. Its an ultraviolet light that is connected to the furnace ductwork and kill bacteria as well as mold that passes by the light. I've read some reviews about it and it sounds as though it does work. However I'm still a little skeptical. Does anybody have one or have any thoughts on it?
posted by Taurid to Home & Garden (7 answers total)

Well, UV does kill bacteria and mod spores when properly administered. I can't say if your device is doing it right, though. Looking around I find lots of reviews that say it had a good effect, but they're worth what you pay for them.
posted by Dipsomaniac at 10:05 PM on November 6, 2009

You should install a new furnace filter every month. I can't speak for furnaces spewing bacteria, but I think there are far more things in the world to worry about.
posted by sanka at 10:12 PM on November 6, 2009

You need to make sure the light is rated to kill bad stuff in a certain amount of time. It depends on the strength of the UV bulb used.

Those little handheld lights have to be held over the area for a LONG time (over 1/2 hour) before they kill the yuck off!

There is a website that talks about the bulbs, and the time it takes for which rating to kill off which stuff. I remember I googled for UV rating kill germs, or something along those lines.

UV DOES kill germs, bacteria, mold, cold and flu, even typhoid! It's all a matter of time and bulb strength! Of course, a very powerful bulb is NOT safe to touch or look at!

Do some more research, if you can afford a good unit, it can only help!

Ugh, I changed our filter after the Station fire (6 months of use plus that fire) The filter was TOTALLY black! Eww! I may go to every 3 months, we get a lot of particulates and dust here...
posted by Jinx of the 2nd Law at 10:28 PM on November 6, 2009

You could get an ultraviolet air cleaner or you could just open a window and let the sun take care of it, it's pretty good at it. Just throwing that out there.
posted by 517 at 10:29 PM on November 6, 2009 [1 favorite]

UV produces 03/ Ozone and that is not so good for you.
posted by hortense at 10:46 PM on November 6, 2009

At their website, it says the 'Swordfish UVA1800RM unit has a 9” lamp.' With air flow past the lamp, I don't think airborne particles are spending more than a second in front of it.

For reference, to sanitize the interior of a tissue culture hood (a space about the size of a dining table and maybe 4 feet in height), we used a four foot lamp for at least 15 minutes. I would not count on the Swordfish to do much more than waste money. Try a HEPA filter.
posted by exogenous at 4:20 AM on November 7, 2009 [1 favorite]

Exogenus has it. UV light does kill micros, but not in a passing air stream. There is some value in using them in the cooling section of your air handler. In the summer this section is wet and things can grow. But in the winter it should be dry and you shouldnt have issues with mold or bacteria growth. For indoor air quality, outside air is your best bet. Filtration is next. You probably dont have the static pressure to put in a HEPA filter in your system. Those have a lot of pressure drop associated with them. I would look for a MERV 13 filter. And change it reguary.
posted by ihadapony at 5:51 AM on November 7, 2009