I get the extra thicc accordion style and I replace them at the manufacturer-suggested 6 months. The duct cleaners told me it should be done every 4 months, but he also said our duct weren't too bad and I hadn't had it done in like 6 years, so...
It’s a scam because as you just pointed out they can only clear the registers and can’t get very far into the ducts.
In most houses ducts have a lot of twists and turns. Some times your ducts will split off from the heavy sheet metal ducts and go down correlated tubes, etc.
It’s damned near impossible to clean the entire ducts and even trying could mean damaging a part of the duct you can’t even access.
The duct cleaners will try to convince you that they can clean every nook and cranny of your hvac system.
They clean like 20% of your ducts and call it good. It’s pointless.
Save the money and clean your own registers with some soap and water. The ducts won’t get cleaned anyway.
The only duct I regularly clean thoroughly is the one for the dryer.
I don't want a lint fire.
The rest, as long as they don't have any obvious build up, they're probably fine. If they do, clean the vent cover, register and whatever I can reasonably reach. 👍
Every 6 months. But I slacked this year and didn't change them out before summer. So I'm going to start fresh now, and then change at the beginning of summer, and then again next year around Thanksgiving.
You dont need the good ones. In fact, sometimes the good ones can damage your HVAC system. If you use 3M filters, use the red label, not the purple label.
What i was told by an HVAC guy who was at my house to fix an issue was those more expensive filters make the system work harder as the filters limit airflow and that additional workload can cause issues.
Nope. HVAC systems are not designed around filters. It’s the other way around. After market filters are designed around marketing and grabbing at your wallet, not caring about your hvac system.
High density filters are going to reduce air flow and your blow motor will be working over time.
Eventually you’ll wear your blower motor out and it will need to be replaced.
The world is full of shitty products. The onus is on you to sort through it.
Filters go by MERV rating. The higher the number the better the filter is at capturing small particles.
Your hvac system isn’t going to be rated for a specific MERV rating. Instead they are rated by air flow. Air flow is going to be affected by your duct work and other factors.
The best is advice is to stick around the 8 MERV rating or lower. Any higher and you may risk damage to the blower motor.
If you want to be sure and know for certain what the best filter size is then you’re best dealing with an hvac company. They can do a static air pressure test. They’ll know based off that figure how much you can reduce air flow (by virtue of the air filter) before the blower starts struggling and therefore select a MERV rating that’s aligned with your current air flow restrictions.
I cannot because I'm just a goofball with a mild interest in home improvement
Wikipedia says HEPA filters became commercially available in the 1950s though so anything older than that I'd bet some beer money would benefit from a less dense filter
I wouldn't think forced air heating systems that old are too common though tbh
We just didn't use a filter at all in our last rental. I know it's bad for the ducts, but the landlord was an asshole, and I wasn't about to spend my money to protect their investment.