FilterLock Furnace Filter Slot Seal – Magnetic Seal Cover for Any 1” Furnace Filter, Up To 25” Long, Reduce HVAC Air Leaks, Green

My home is 15 years old and has a furnace with a filter slot on the side that doesn’t have a cover, leading to dusty air leaking out. I bought the AllergyZone FilterLock Slot Seal to fix this, and I am extremely pleased with the results. Installation could not have been easier – it’s a two-piece magnetic strip that I just snapped over the open filter slot. It took literally seconds to attach, and it fit perfectly along the length of my 1-inch filter slot (no gaps at all). I immediately noticed that when the blower kicks on, there’s no longer a puff of dusty air coming out. The seal is nice and tight. The improvement in air quality was almost immediate in my home. I suffer from allergies, and I used to see dust collecting around the furnace closet and could smell a slight mustiness whenever the heat turned on. After using this FilterLock cover, that issue is gone – my air now feels cleaner and my HVAC system is pulling air only through the filter as intended. I even think my furnace is running more efficiently because no unfiltered air is bypassing the filter. It’s such a simple concept but works brilliantly. The magnets are strong enough that once it’s on, it stays put. I haven’t had any problems with it slipping off, and it’s easy to remove and reattach when I need to change the filter. Another plus is the material – it’s a durable vinyl that seems like it will last through many filter changes. It’s reusable, so this $20-something purchase will keep benefiting me indefinitely. I also appreciate that it’s a bright green color, which is a visual reminder to check my filter monthly. All in all, I’m very happy with the FilterLock Furnace Slot Seal. It solved an issue that had been bothering me for years in an affordable and effortless way. Every home with an open filter slot should have one of these. Five stars for making my air cleaner and my life easier!

This is an amazingly simple invention that finally solves a problem that we had in our house. The area where I slide in my filter in the furnace had big gaps on the sides, top and bottom. To make matters worse there was an opening on both sides of the furnace so that you could install the filters from either side. So the air was getting sucked in from both sides and probably very little was coming in from the cold air returns. It is beyond me why furnace installers have not figured out a way to fix this problem. I thought about calling someone to build a door or rework the metal so that there was a tighter fit but that would have cost a fortune. This little invention while perhaps not perfect, improved the situation 99%. I still may be getting some air going around the filter inside the cover but at least my system is relatively closed off so I am getting better air flow and I would not be surprised if this cuts down on my bills over time. This consists of two pieces of heavy duty plastic that measure 4.5" x 14" each. The plastic reminds me of the type that you would find on a pool liner. It's pretty tough but flexible. There is a magnetic strip inside the plastic on one end of each piece and two that run up each side. The magnets inside the plastic being broken into pieces allow you to fold them over in a couple places to get a good fit on your duct. Depending on how your duct work is constructed this may work better for some than others. I would urge you to take a look at my photos and then take a look at your ducts to see if this will work for you. For me it works perfectly at the bottom but at the top the way they constructed my ducts I have to fold it over and put it on a slight diagonal. I found that the magnets were strong enough to stick to my duct work but pliable enough that I could bend them at the top where I had issues with the way they fit in order to get a tight seal. They come in two pieces so that they can bend over on each side and still get an exact fit for a variety of sizes. The two pieces overlap enough that there is no air escaping. My filters are 16" at the opening. One thing I may do to make changing the filters and re positioning the covers easier is to tape the top edge and the bottom edge to the duct. It's not such a big deal for the bottom, but the top edge is wedged in to fit my odd fitting duct work so I think if I did not have to remove it completely to replace the filter that these will maintain a good fit longer. I felt these were a decent value for what I paid ($8 each) I had to buy 4 so it was $32 but I would have spend a lot more had I called someone to rework the duct area and install a cover. Plus some covers still do not seal off the opening completely. Thanks for reading my review Becky Brooks *I paid full price for this item it was not a free sample

Great concept. The more care used to place the pieces to achieve the most complete seal, the best results will be gained. Where the two pieces overlap, the center area has a potential small leak area. Nevertheless a vast improvement covering up this very leaky area. Fair value.

These are fabulous, makes for a nice seal yet easy to remove when it's time to change the filter!

Works really good. My filter just slides in an open frame slot on side of duct. There were gaps and you could feel unfiltered basement air being sucked in the gaps. This solved that issue. Recommended.

These are okay but there are other options that do just as good. While these are magnetic, there are some situations where these won't work properly. I bought these on a recommendation. They're easy to use and good value for the money. Easy to keep clean and durable.

These covers work well. Definately keeps air from escaping or coming in around a lose fitting filter.

Easy to install and remove, stays put when placed, seems to keep air/dust out, much better than old tape system, tape would last 2-3 applications then would need to replace because the stickiness becomes ineffective

I thought this was a very unique idea when I saw it, so I had to have it. I believe it works really well to keep the dust, dog hair, and other allergens out of the furnace slot. I also feel that this slot seal is helping to keep my furnace motor cleaner and having less stress on it without all of the above things mentioned above getting in.

This was a quick product to slap onto the furnace filter opening, and it seems to work adequately well. However, I like to print the date on my furnace filters so I know when to change them, and this product (being opaque) obscures the view of everything. Given tthe price:value ratio and the opaque material, I can't give it 5 stars; 4 stars seems about right, given the easy of use and practicality. In retrospect, I could have saved some money and made my own seals -- do yourself a favour and buy some "magnetic tape" with a self-adhesive backing. Then get some clear plastic (clear plastic garbage bags would work well, or even better, get some 6 mil poly vapour barrier) and cut them to size (e.g. 4.5" x 18" for a 16" filter, or 4.5" x 27" for a 25" filter) and fit with magnets (cut a couple 4.5" strips, put them on, and then cut and put on long strips). Chances are you'll be able to make a few of these for friends and family using the roll of magnetic tape you bought for less money than a single set of these seals.

I had a huge gap in my furnace and it's filter. These are magnetic and hold well and can be shaped. Sealing up the holes and gaps makes the furnace pull air from the cold air returns in your home, which should make it more efficient.

Easy to install. Provides a much better seal around the filter. Happy with my purchase. Thank you.

perfict works great