View Full Version : furnace filters

Supa Dexta
08-12-2007, 05:27 AM
Just wondering if anyone uses a special furnace filter for allergies? My gf gets pretty stuffed up sleeping, but its only when the furnace is on, we moved in last winter, shes been fine all summer, but the furnace was on again lately and its just started up again. She has a couple cats and is fine and the landlord upstairs smokes.. but it would seem as though its dust in the furnace or something triggering it, since the air exchanger in the summer never caused anything....

08-12-2007, 11:29 AM
There are a few options.

1) A good furnace cleaning.
2) 3M Filtrette filters.
3) Electrostatic filters.
4) Electronic air cleaners.

08-12-2007, 12:04 PM
Rona/Totem sell a couple of really expensive 3M ones that are really good at filtering out ever bit of dust. You just have to remember to clean them every 3 months or so. They are reusable so they do last a lot longer then the crappy $5 ones.

08-12-2007, 03:08 PM
Do you own the house?

Supa Dexta
08-13-2007, 01:55 AM
nope rentin'... It's prob just dirty old edmonton causing it.. Best part of moving there was I'm never home.. :poosie:

08-13-2007, 08:29 AM
Before you worry about a furnace filter get the carpets cleaned.

08-13-2007, 09:59 AM
I would just go get one of those 3M filters than, get the blue or the red one. Do not get the purple one as it will restrict airflow like crazy.

If you owned the house I would say get an electrostatic filter or a media filter as they will work much better and are cheaper in the long run. No point in spending mucho money on someone elses furnace.

08-13-2007, 10:02 AM
Switching from carpet to hardwood or tile makes a huge difference, but I'm not sure that's an option for you if you're renting. A lot of shit just stays in the carpet.

08-13-2007, 10:53 AM
Thing with the 3M Filterette refillables is that the refills are tough to find in stock... and the regular non-refill paper ones are pricey.

08-13-2007, 01:08 PM
Get your furnance/ducts cleaned, clean the carpets, and get an electrostat (reusable) furnace filter to start. The electro stats are around $60 - $100.

Chances are there was dust that settled in the furnance ducts over the winter and that is what is aggravating her allergies.

If you are renting, ask the landlord when the vents/carpets were last cleaned. Explain the allergy problems.

08-13-2007, 01:13 PM
I have an electronic filter installed in my furnace/AC. It cleared up 99% of my morning stuffyness. Only on really bad days with a lot of pollen ourdoors in the spring do I get stuffy in the morning.

08-13-2007, 01:29 PM
While you're at it buy a humidifier (cool mist) for your bedroom.
Helps get rid of that sore throat/dryness in the morning.

And get a good nasal spray for those really bad pollen days

Supa Dexta
08-14-2007, 08:43 PM
cool thanks guys.. hardly any carpet in the place, but I'll look into it..

08-07-2019, 10:59 AM
Bump from the dead
Just wondering who around here is using the expensive filters over than the cheapo ones and if they make that much of a difference.

08-07-2019, 11:10 AM
I'm using the cheapo ones, when I got my furnace cleaned, the guy even recommended just using the cheapo ones but change them more frequently. Said the expensive ones, might constrict the air flow too much causing more strain on my blower and breaking more expensive parts. Furnace is a mid-effieciency from 2000

08-07-2019, 11:11 AM
A good post about the differences between various furnace filters: https://actionfurnace.ca/is-there-really-a-difference-between-the-different-type-of-furnace-filters/

08-07-2019, 11:12 AM
Agreed. Buy cheap, change monthly.

08-07-2019, 11:14 AM
I use the stupid expensive filters in the summer with the smoke - they literally clean the air in the home better than outside.

Otherwise, I use washable filters in the summer and regular paper filters (good flow rate) in the winter.

I also have UV lights setup in the ducts, not that they do much (as per studies) but even 20% effectiveness is worth it.

Humifidier in the winter is also very important.

08-07-2019, 11:18 AM
I use the cheaper ones in the summer to increase airflow for my AC unit. Was getting freezing with the "better" ones.

08-07-2019, 11:22 AM
I use the wide (5?) ones that my furnace can accept, my math is wider = more surface area = less pressure drop = more airflow.

Airflow is king, whether its from using a filter that does nothing ( no pressure drop ) or a wider higher efficiency filter.

Hard to find wide and cheap in my experience, I just buy 4 packs on amazon.

08-09-2019, 10:09 AM
I buy these guys when they go on sale (which they are right now)

Just remember to change them often, I do mine every 2 months and haven't noticed any airflow restrictions

08-09-2019, 11:02 AM
for my furnace with the a/c coil i use cheap fibreglass to get maximum airflow. For my other furnace i use a pleated, but lowest MERV rating (8), again for better airflow but still get some filtration going on. Fibreglass i change monthly, pleated every 2 months.

If i had new furnaces with powerful fans i'd probably go with a bit higher MERV rating.

I just started using this company for pleated.

I got a 10 pack of 16x25x1 merv 8 pleated filters for like $70 or so. For the fibreglass i get them from Home Depot since they are like $5.