I have year round allergies as well...dust, dust mites, grass, trees, weeds, mold. I have an Oreck air purifier in my bedroom, it is basically on 24/7 (per my allergist). I really can't tell if it makes a difference....since I'm also allergic to outdoor things...and I do have to go outside, I can't just hang out in my bedroom... So I really haven't been able to tell if it really makes a difference...sorry:( but living with these allergies year round makes life difficult:(

I completely understand your struggle, as I have the same thing. A couple years ago we invested in a whole house air cleaner that goes through the furnace. Although there have been some technical issues (where to hookup, making enough space for it etc.), it helps a ton!
Ours has 3 filters-main dust, large particle one, an electric field that kills a very high amt. of spores etc. that go through it, and a smaller particle filter.
I vacuum these quite often, and it is amazing how dirty they get! When spring hits (like now), and I am struggling with all the blooming of tree and grasses, it helps at least cut down on my reactions inside. We leave shoes outside now too.
Not a perfect fix, but a good tool is what I would call it. :)
Good luck!

I wish we could afford a purifier like any of those. My Dad tells everyone I'm allergic to life. When they did my skin test 72 type's of trees, grass, weeds, and mild. It sent me into shock this doesn't include dust, dust mites, cats, dogs, horses, anything with feathers.,and wasps and bees You get it. We moved to Colorado and until this year they have been managed. But have any of you ever hear of indirect allergies it is when you eat certain food that you have a weak allergy to them mosty it goes unnoticed but when your histamine is maxed by our severe ones those weak ones will just send you over the edge mine are melons, and any thing. with citrus fruit. One thing I learned is when you need more antihistamine then your allergy meds take Zantac. I was shocked to also use liquids not pill form it was take affect faster. My mother n law gave us a Alamo humidifier with a filter it helps and it doesn't cost a lot I wish you all well

YES THEY WORK! Oreck is a good one, I own this one personally. They run $100-$300.

Vapoor -eze clean air 5100 is also a good one that I also have. It is only good for a one room area thought it has a attachment far you car lighter so you can use for your car as well. It usually run's around $50.

Make sure any air purifier has a heap filter or it won't clean the air like it should.

Sorry I meant HEPA filter.