Just looking for opinions/knowledge. I'm getting a new furnace installed (York YP9C) this week and was wondering about filter sizes. Typical install will be with a 1" wide filter but the installer said if I wanted to go to a 4" or 5" wide filter it wouldn't be a problem. My instincts tell me to go with the wider filter (thinking more surface area=better filtering) but this isn't my field so I thought I would ask the pros their thoughts. Trying to go with a good to better quality filter to get allergens out of the air without resorting to a whole house air cleaner which would be way overkill for us. Thoughts?
Is a wider filter better?
MRAD
1 - 20 of 20 Posts
Just looking for opinions/knowledge. I'm getting a new furnace installed (York YP9C) this week and was wondering about filter sizes. Typical install will be with a 1" wide filter but the installer said if I wanted to go to a 4" or 5" wide filter it wouldn't be a problem. My instincts tell me to go with the wider filter (thinking more surface area=better filtering) but this isn't my field so I thought I would ask the pros their thoughts. Trying to go with a good to better quality filter to get allergens out of the air without resorting to a whole house air cleaner which would be way overkill for us. Thoughts?
OK it's what I figured. A couple of the guys that came and gave estimates spec'd 1" saying that the variable speed motor would compensate for restriction by ramping up to maintain airflow...seemed like backward logic to me. I'll get the wider filter installed.
Joined
·
2,765 Posts
Be aware that the position of any air filter is critical to best performance, and many media(wide) filters are placed in a compromising position.
The best location is with a straight duct on both sides of the filter. How that would work depends on you system particulars.
Best of luck!!
The VS blower will ramp up to compensate. It uses more electric when it has to ramp up to compensate for the 1" filter. Defeating the purpose of having a high efficiency VS blower motor.
That was my thinking too.
Unfortunately position may not be ideal as there is a 90 degree bend (duct runs down from ceiling and 90 degree bend to enter the furnace) right where the filter would be going. I can't see how they would run a straight duct on both side without moving the hot water tank etc. I'm guessing the while there would be losses the 4-5" may still work better than the 1" it would replace.darctangent said:
Thanks for the replies guys!
Joined
·
2,765 Posts
suit yourself. properly installed, your system will be in operation for 20 years, maybe more. restriction to airflow is one of the more significant determining factors to efficiency and longevity.
This isn't a matter of suiting myself it's a matter of working with what I have and within a budget that isn't huge to begin with. The ductwork and furnace was installed almost 20 years ago. I'm sorry but I just don't have the $$$ to have an overhaul of our ductwork, move the pump pressure tank, water softener system, sump pump system and hot water tank out of the way (or a supporting wall if we go from the other side) to maximize the performance of the HVAC system. If I could I would but I just can't.
Just get out there and shake that money tree until you have enough money to make it happen. Geesh, kids nowadays.
Joined
·
2,765 Posts
I fully understand sometimes space limits what you can do, I deal with it everyday, believe me! I also (obviously) don't know what you are dealing with exactly. Your new furnace might be wider, or narrower than the old one, you might have pipes that intrude into the space I would like to use for ducts, etc. as they say- I can't see from my house"
On top of all that, the economics of the home service industry has made this type of work expensive- believe me I understand.
The one thing that I can tell you that might help is that if you add the thickness of a typical Media filter case- approximately 7 inches, with the width of a return air drop (varies, but between 8-12 inches) you might have the room you would use for a media filter installed in a better manor than what many companies do. most of my return air drops are between 15.5 and 20 inches wide- that's just over what? 50 cm on the upper end?
Like I said, I don't know what you have to work with, but I start with good design to produce good results. I only add technology to add a final layer of icing on the cake if you will. I have found the the technology isn't much good without the design to go with it.
Below you see one of the wider return air drops. For even better performance utilize a side/bottom return air configuration.
![]()
On top of all that, the economics of the home service industry has made this type of work expensive- believe me I understand.
The one thing that I can tell you that might help is that if you add the thickness of a typical Media filter case- approximately 7 inches, with the width of a return air drop (varies, but between 8-12 inches) you might have the room you would use for a media filter installed in a better manor than what many companies do. most of my return air drops are between 15.5 and 20 inches wide- that's just over what? 50 cm on the upper end?
Like I said, I don't know what you have to work with, but I start with good design to produce good results. I only add technology to add a final layer of icing on the cake if you will. I have found the the technology isn't much good without the design to go with it.
Below you see one of the wider return air drops. For even better performance utilize a side/bottom return air configuration.
Something like in your pic may work. I asked about running the filter on the drop in the fashion that you have but with the drop being 14x18 he thought there may be issues fitting a decent sized filter on it. I've added a pic of how it's situated. Personally I think there is room in the area between the top of the hot water tank and where its exhaust bends towards the wall but I'm not an HVAC tech I'm a carpenter...my ideas don't always fly in other trades 
. There's maybe 3" between the drop and HWT and 4-5 between it and the furnace. I understand about good design procedures first and tech second. Whether the techs that will be installing the system will be as diligent about it as others will be I don't know. I'll certainly mention it but unfortunately I won't be at home when the install is being done do to my work schedule. I was supposed to have the day off but looks like I'm getting put on another job to get it done in time...oh the joy...
![]()
. There's maybe 3" between the drop and HWT and 4-5 between it and the furnace. I understand about good design procedures first and tech second. Whether the techs that will be installing the system will be as diligent about it as others will be I don't know. I'll certainly mention it but unfortunately I won't be at home when the install is being done do to my work schedule. I was supposed to have the day off but looks like I'm getting put on another job to get it done in time...oh the joy...
Joined
·
2,765 Posts
MRAD, looking at your photo it seems there would be room for a 16x25 filter, but I'm not there. I tipicaly replace the RA drop so that I match the duct dimension to the filter opening and the trunk connection for maximum airflow capacity. Most guys won't be accustomed to doing that, but It's part of how I squeeze out the extra air volume on my jobs. I realized that's not going to happen here but just explaining process. It would require adapting sheetmetal, but I think the aprilaire 1410 filter case would fit your situation. If not then honeywell would have something to fit the bill. The Aprilaire 1000 series is a recent find and I like them because of their low static pressure drop across the filter and long life. Good stuff. Not certain that's available in Canada. I know you guys have a tough time getting certain products. You guys do have some nice furnace designs though! I think the first 90%'ers came out of Canada.
It will be important to match however much air your furnace needs to move to the right filter size to maximize airflow at a low static pressure. hope that helps!
How big is the new furnace (how many BTU's?)
PS- former Commercial Carpenter, UBC local 510
It will be important to match however much air your furnace needs to move to the right filter size to maximize airflow at a low static pressure. hope that helps!
How big is the new furnace (how many BTU's?)
PS- former Commercial Carpenter, UBC local 510
Yeah I'll have to see if they can accommodate it there. The wider filter won't cost me anymore if he can accommodate it but I'm assuming that's putting it where the current 1" unit is now. Not sure how much extra they would charge to install it on the RA drop if they have to use different parts to do so. I'll have to see what they can do. New furnace is a 60kbtu York YP9C unit. Funny you should mention being a former commercial carpenter...after dealing with the ins and outs of getting a furnace/ac system installed I've been considering a jump to HVAC since it seems there aren't a lot of meticulous installers in my area lol
Joined
·
2,765 Posts
Lots of guys in HVAC started out as Carpenters- or worse, LOL. Trust me when I say this stuff doesn't come easy. It's WAAAAAY more technical than the outsider would ever know. There's what is on the surface, what you can see a guy doing, but then there are things going on that you don't see, you can't see. Think of a accountant doing the books, or an attorney, or whatever. You see what they are doing but you wouldn't understand why they are doing it a certain way one time, but not another. I'm 21 years in and still learning. You'd have to start with somebody else so you can learn all the bad habits before you go it alone. I Figure 3 years if a guy pushed himself and studied hard, and that's only if you get all the right training before you might be ok on your own. Guys who don't get the right training never figure out how to do it right, how to do it better. They spend their whole career jacking stuff up and not knowing what's going on. They put a system in and when it's noisy, or runs all the time and doesn't keep up or whatever, they just say "that's the way it's supposed to work, or These damn ____ they're always giving me trouble I wish they'd go back to using the old _____. Sometimes what their saying is true, sometimes they just don't know what they're doing!!! Customers can't tell the difference.
There's my two cents.
If you were really interested, bookmark HVAC-TALK and write a note down about me. I'll try to steer you in the right direction.
best of luck!
BTW- aprilaire 1410 would work great for the kind of airflow a 60K furnace would call for, but I think your installer has different plans for you. It's a good thing you have a small furnace. The bigger they are the more air they need to move, and that makes the ducts and the filter setup all the more important. smaller is easier in HVAC. not easy, but easier!
Ask him to measure total external static pressure on the system after it's set up. It's quick and easy for anybody that knows how. Let us know how it all turns out.
There's my two cents.
If you were really interested, bookmark HVAC-TALK and write a note down about me. I'll try to steer you in the right direction.
best of luck!
BTW- aprilaire 1410 would work great for the kind of airflow a 60K furnace would call for, but I think your installer has different plans for you. It's a good thing you have a small furnace. The bigger they are the more air they need to move, and that makes the ducts and the filter setup all the more important. smaller is easier in HVAC. not easy, but easier!
Ask him to measure total external static pressure on the system after it's set up. It's quick and easy for anybody that knows how. Let us know how it all turns out.
I appreciate the advice...I can't imagine going back to school again to start at the bottom of a new trade at 40 years though...as much as I'd like to. I'm going to send the installer some pics tomorrow and maybe he can figure something out for when they get here Thursday. There's two crews coming to install the furnace and AC so maybe between them they can get it sorted out the way I'd like it. Thanks again for all the input!
Well talking with the guy I've been dealing with sounds like it may be a headache to do. He's talking about using transitions on the RA drop to get a 20x20 filter in there. I've measured everything up for him (he was going to do it but I couldn't be home to let him in) and while there's room to get a 20x20 in there I don't know how much the transitions will take up space wise so that may be the deciding factor. Is there going to be that much of a difference flow wise mounting the filter in line with the RA drop vs where the 1" filter is now? Adding the in line set up will add about, how do I say this without a price, couple of hundred dollars shy of half a thousand which I haven't budgeted. Big picture wise the cost of adding the filter is a fraction of the total install cost of the furnace but I already went a little over budget to get the better furnace. I guess ultimately is the difference flow wise between in line and where the filter is now worth the added expense when it comes to the longevity of the furnace?
Yes saw that post and the expense is roughly the same as the inline method. Raising the furnace 2' will also have it higher than the combustion air inlet pipe. I don't know if there's any codes that affect how that pipe is run but to get it to exit at the same spot in the wall (it's siding and I'd rather not punch another hole in it if I can help it) would require it to get dropped about 7". It's something I'll mention though thanks!
1 - 20 of 20 Posts
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
