One of the problems when trying to compare the different types of furnace filers available is that there is quite a bit of information to sort through. When trying to compare efficiencies, brands, MERV ratings, price, characteristics and the types of filters available, you can suffer from information overload.
The first thing to do before sorting through all of the above information is to determine what type of air filter is best suited for your specific needs. After deciding on the type of filter you want to use then it is time to compare and review the filters of that type to make your decision.
I have compiled a chart to help compare air filters most commonly used in heating and air conditioning equipment. It lists some of the pros and cons of each of the common types of filters and also lists some important details of each type.
Question: Do you think there is any problem with ultraviolet furnace filters as far as it depleting the inside of the Duct liner or plastic or rubber that the ultraviolet rays bounce off.
It depends on the type of plastic your condensate pan is made of. Some of the newer drain pans are UV resistant but you would have to check with the manufacturer to know for sure. UV also causes rubber to deteriorate.
There are a few of things you can do to avoid this potential problem.
- Install the UV air cleaner in the return duct before the ac unit. This way the light doesn’t contact the drain pan or any other plastic parts.
- Mount it in the supply duct far enough away so that it doesn’t contact the drain pan or any other plastic parts.
- Place a shade of some sort above the condensate pan to prevent the UV rays from contacting the drain pan. You have to be not to do anything that can potentially affect air flow.
What I recommend is that you install the uv air cleaner in the supply air duct. This will treat the air before it enters your living space and destroy most mold spores, bacteria, viruses and other pathogens.
I often read that UV lights should also shine on the evaporator coil to destroy any mold that may grow there. I have worked on thousands of air conditioners and have seen very few with mold growing on an evaporator coil. I have seen many dirty evaporator coils but that doesn’t mean there is mold.
I have seen condensate pans, drain lines and p-traps with some nasty looking things growing in them that I handle carefully. The reason things grow in these places is because a lot of contaminants from the air collects there. The evaporator coil is wet from condensation most of the time and as air passes through the evaporator coil, contaminants collect on the coil and many of these contaminants are washed away with the moisture on the coil as it drains off. So the coil actually stays fairly clean for a long time when using efficient furnace filters and a lot of the contaminants collect in the drain pan, drain line and p-trap. You can treat these components with a mixture of bleach and water, about 10 parts water to 1 part bleach.
If, for some reason you are having problems with mold on the evaporator coil contact your service technician and have him or her clean the coil with one of the many chemicals available. There are environmentally friendlier cleaners available also.
Regarding the duct liner, I don’t think UV light would have any effect on it.
Update Dec31/08
I submited this question (Do uv lamps damage plastic condensate pans and rubber?) to a popular UV air cleaner manufacturer and this is the reply that I received.
This depends on if it is plastic or rubber not rated for UV exposure. The only rubber we know of that is affected by UV light is rubber manufactured in China, where a different formula is used in their mix. As for plastics, Schedule 40 and SDR 35 PVC is affected (usually used for plumbing / sewer drainage). PVC will brown, like a paper plate left in the sun all summer. Wires (electrical) are not affected by direct exposure to UV light except old wires used prior to 1965 that used a different jacket than what is used today.
Question: I currently have an electronic air filter, (electro-air) by White-Rodgers, and the power pack goes dead every 15 months or so. It is getting costly to replace each time. I am thinking about going to a cartridge type filter instead. Can I do this, since the ductwork was set up for the electronic filter and is 6 1/4″ wide between the furnace and the air flow duct.
You can probably install a 5″ thick pleated filter into the unit. Remove the electronic element and slide in the pleated filter. Measure the inside dimensions of the unit to ensure you get the right size filter. You can order 5″ pleated filters here.
This would probably be the easiest fix. You could also modify the unit and install a 2″ pleated filter. You just need to make sure the filter is held in place properly.
You can get special order sizes here.
