Home HVAC filters
- Thread starter dishdude
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To me, you have (2) options, a standard air filter that keeps dust, etc out of the heat exchanger and blower and then you have actual "air cleaner" setups. Those are the ones that use 4" filters that last 3-6 months. Neither are interchangeable.
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I definitely understand your frustrations there. I am in a new subdivision with homes less than 5 years old and have spoken with several neighbors regarding HVAC related issues systems being undersized etc. Neighbors have big mouths until you call them out.. I would like to start a petition in this issue none are willing to go to bat with me.
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if you're selling k&n's lolRemember folks , " A dirty air filter is more efficient " .
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Steven Lavimoniere's service area tends to have undersized air intakes as the installers seem to be saving time and money. So he recommends low restriction filters, changed frequently to get some semblance of air flow. I think that is more critical for AC rather than heat.
Then if one wants cleaner air in a room, do that with dedicated air filtration devices.
We liked this air purifier blog. And have some sharp units. One has a car air filter taped on it lol.
https://air-purifier-power.com/
Then if one wants cleaner air in a room, do that with dedicated air filtration devices.
We liked this air purifier blog. And have some sharp units. One has a car air filter taped on it lol.
https://air-purifier-power.com/
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love this guy watching his videos especially plumbing has taught me a lot.
Condenser or evaporator????
I have no condenser , I have geo thermal
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In ultra-humid Tokyo, we had to clean the split-system's evaporator coils every year or so for odors.
We had fewer issues in dryer climates. YMMV.
We had fewer issues in dryer climates. YMMV.
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Use the cheapest filter available, or none, is a work around when the PSC motor in a furnace is dying. Example is when a furnace short cycles as the cfm is too low.
Modern furnaces have ECM motors and often the filter is 4”. Ours is, MERV 13 and now costs $50.
My uncle has a similar setup and to defray costs he stacks 4 1” cheapies
Imagine doing the above especially if allergies
Modern furnaces have ECM motors and often the filter is 4”. Ours is, MERV 13 and now costs $50.
My uncle has a similar setup and to defray costs he stacks 4 1” cheapies
Imagine doing the above especially if allergies
uh that's 16x the restriction of a 4" filter (generically)Use the cheapest filter available, or none, is a work around when the PSC motor in a furnace is dying. Example is when a furnace short cycles as the cfm is too low.
Modern furnaces have ECM motors and often the filter is 4”. Ours is, MERV 13 and now costs $50.
My uncle has a similar setup and to defray costs he stacks 4 1” cheapies
Imagine doing the above especially if allergies
Yes, I have an Aprilaire system on the Carrier air handler in my Florida house. Since Covid, the price of a four-inch 410 replacement Aprilaire filter has gone from $37 to $54. At least they are good for 12 months or more in a clean home without pets and where windows are rarely opened.
* 4 x 16" x 25"
* I change it at 18 months (might try 24 months) .... they are expensive filters and at 18 months, look good but a little grayish color.
Most people would change them after 12 months.
Initial gage readings would depend on-
number of people in house,
pets,
carpeting etc.
Initial gage reading also depends on duct sizes, and number of return lines.
I'm not in the business, only an excessive compulsive homeowner for 38 years.
The differential pressure gage I use is an acrylic (red dye) laboratory type made by Dwyer.
They also make a less expensive model for homeowners.
https://www.grainger.com/product/2T...p.ds&msclkid=feb190be9ac01af54fb0f7431963b4a5
Temp drop across the evap coil industry standard is 18° to 24°. 20° is what most techs set blower speed up. Condensate and coil that is saturated with moisture is 100% RH at 40°. When air leaves the coil temp raises and RH drops fast and is lower than the return air. Total agree with your assessment running the blower on the on position dries out the coil and pan when cooling isn't calling.Here is what I have been told....YMMV....
Air flow determines how much water is removed from the air in your home (assuming a properly sized and efficient AC system). If the air flow is too great, too much moisture is drawn off the coils and back into the air resulting in higher humidity.
Not enough air flow and the coils can freeze condensate and block the system. It's a balancing act.
The air flow is adjustable by setting the fan speed and by filter restriction.
Just keep in mind that it is crucial to keep dust and dirt off the coils so good filtration is important.
I'm just the messenger...don't shoot
Variable refrigerant flow still keep the evap saturated by vary blow speed and coils are more efficient because their enhanced. Blowers almost never turn off.
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Ours came with the 413. In 2020 they were four for $122. Now basically $200.
Again, there's a reason why a contractor says to use the cheapest possible and change it often, even every week. That's when a system is not getting replaced and the PSC motor is failing. This can get a homeowner by, it's a lot better than freezing when temps are single digits and the furnace is short cycling. In an emergency sceneario, the filter can be removed altogether. Seriously. Measure the temp leaving the furnace, if it's restricted, it will be high.
Imagine getting a brand new system, and the installer puts in a 1" filter, when the furnace has a ECM motor.
This notion of "restrictive" is always bad, is why K&N can still sell filters today!
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Our old 1999 system installed by the house seller had jumpers. Normally AC is set higher than heat. But when the system began to fail, the contractor gave me that advice--find the cheapest filter you can, $1 or so, and change it every week. This way, you do not have to replace your system now. He said your PSC motor is like an old man that can no longer blow.Here is what I have been told....YMMV....
Air flow determines how much water is removed from the air in your home (assuming a properly sized and efficient AC system). If the air flow is too great, too much moisture is drawn off the coils and back into the air resulting in higher humidity.
Not enough air flow and the coils can freeze condensate and block the system. It's a balancing act.
The air flow is adjustable by setting the fan speed and by filter restriction.
Just keep in mind that it is crucial to keep dust and dirt off the coils so good filtration is important.
I'm just the messenger...don't shoot
The 2020 system has a ECM motor and it handles the 4" MERV 13 no problem. There is no benefit to using a 1" $1 filter (if it still exists), it's not going to prolong the motor life, it was designed for the 4".
When our system was installed, the installers programmed it wrong. Both heat, and AC, were set for the same CFM, in the 600 range. So guess what happened? What you said.
Despite being 95F outside, the vents were blowing 43F, there was tons of condensation from a vertical duct going to the 2nd floor, and 3 days later, the entire system iced up.
If a person were to oversize the condenser, the same will happen. I have actually met people who said, oh, your house has a 3 ton system? We'll put in a 4 ton one it only costs $300 more. That is not only inefficient, it will cause folks to be uncomfortably warm, because it won't run long enough to remove humidity (short cycle). It's also possible to have inadequate airflow with the current ducts.
System must be sized properly to use higher efficiency filters. If not evaporator can ice up. I have custom built home. HVAC systems were sized for pleat filters. 1” Merv 13 in filter grills & 5” Merv 13 filters in filter box at furnace/airhandler. After 25 years evaporators are clean like new.
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When the 1999 system was beginning to fail, I called a contractor due to the advice online (once in a while we have to realize there's plenty of bad and inaccurate advice, even on BITOG! lol). People said our A coil needs cleaning, that's why your AC is not cold. You had a dog--there will be lots of dog hair clogging it up. I'll save you $10k plus--get it cleaned for a few hundred.
When the contractor arrived he said why do you want your A coil cleaned? It's not gonna be dirty you've always ran with a filter, right? To my disappointment, he would not take the $200 he quoted me to clean it. Threw a line set on the condenser and said you have a leak and R22 is getting expensive.
Flash forward to 2020 when the old system was ripped out. I saw the A coil laying in the driveway. It was clean as a whistle.
We're all subject to following bad advice--I'm the first one to admit when I do something wrong. Up until 10 years ago, I did not rotate tires from one side to the other, even when tires were not directional. Someone on the BMW forum pointed out there's no such thing on non directional tires. heck, costco routinely swaps from one side to the other. That was a 1970's thing when belted radials came out.
I'm not in HVAC but I don't believe that buying the cheapest filter because it's less restrictive, applies, to a modern system. It does, to a failing old one.
P.S. I posted immediately when the new 2020 HVAC was installed in July, and the vents were blowing 43F. Only one person said you've got a serious problem. You better get them back asap and fix it. either the blower is not set properly or you have inadequate duct work, which should not be the case if the new system is same as the old. One person. The rest said that's a new efficient system. 43F out the vents when the room is 75F.
If a system was designed right with a AT LEAST a 2 inch thick filter as a bare minimum you would not need to reduce filtering capacity, because your system was not designed right. Too many people's systems are designed to the lowest possible standard that when the 1 inch filter gets even lightlt dirty they can hit their high temperature overload switch. in heating mode. A 1 inch filter even in a 20 X 25 filter box to me is not a good design. When I installed my daughters furnace/A/C set up I pulled a permit as when she goes to sell the house and move up IF she wants, the house will be worth anther $10,000+ more because in her area in St Paul a good chunk of older homes are renoed without permits. When you sell in an area like that, part of your selling plan is the whole house was renoed with full permitting by the city.
KInda funny when the heating and air inspector came and said "you did not need a 4 inch 20X25 filter on this 60,000BTU 2 stage." I said oh yes I do, You can't have enough filtering "area" when you are running 11 to 16 MERV. He agreed it is over the top, but an optimum choice to never have a flow issue. I buy the 4inch MERV 13 by the case of 6 for $200 and they last me 3 years. Plus the 6 cheapo fiberglass filters I add to prefilter and "cake".
KInda funny when the heating and air inspector came and said "you did not need a 4 inch 20X25 filter on this 60,000BTU 2 stage." I said oh yes I do, You can't have enough filtering "area" when you are running 11 to 16 MERV. He agreed it is over the top, but an optimum choice to never have a flow issue. I buy the 4inch MERV 13 by the case of 6 for $200 and they last me 3 years. Plus the 6 cheapo fiberglass filters I add to prefilter and "cake".