I don’t disagree with “Heating the filament will remove more moisture than desiccant” given a short amount of time. Heating is always the “quick fix”.
But if you don’t need to print with the filament right away, a dry box with well stocked desiccant will do an adequate job of drying the filament for first use, without shocking it with heat and has the added benefit of keeping the filament conditioned.
I have been using this method with great results.
The Wisedry packs have a color changing indicator that I check everytime I open a box to retrieve a spool. I have spare dried/recharged packs on hand when they need to be swapped out.
Since the Wisedry packs are more hygroscopic than the filament, the moisture will migrate from the one to the other.
Those that rely on heat drying their filament every time they want to print with it, will see its properties degrade.
The way I see it, even simply putting a small heater such as:
( https://www.amazon.com/gp/product/B0C3VS2T9Q/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 )
from amazon into a clear sterilite box would get you halfway toward having your own DIY filament drier. To avoid hot spots that might damage your filament, pick a bigger box, and perhaps put in some extra fans inside the box to further even out the heat (similar to a convection oven).
Well a nice long sting for the PETG at 65 and no problems at all… not even close to melted. So it must be your unit.
My next goal is PET-CF, which Bambu Labs says you should dry at 80C for 6 hours, fresh out of the wrapper, before trying to print with it. Vision miner says to dry their version at 90C using input air that has already been dried to a dew point of -40C. I don’t know how one would even do that last requirement.
The printdry v3 can be set to 85C, but I’ve checked that with temperature probes, and the truth is it delivers closer to 75C.internal air temperature at its 85C setting.
PET-CF is not as bad as PA for water absorption, about half. Can try just printing it without drying.
You don’t need a filament dryer for the Bambu Lab AMS. Ic comes equipped with two storage areas for silica gel packs, and there are a number of printing projects for adding further silica gel containers that fit between the filament feeders. In addition, the AMS measures its internal humidity and provides an easy to read report on the results.
In case of individual filament reels that may have picked up moisture, and which I feel have not degraded in an unrecoverable way, I dry in a Sunlu S1 unit. All of my bulk offline storage is kept in hermetically sealed containers, with silica gel packs, and with WiFi humidity monitors. I keep new filament in its plastic bag until needed.
I live in the Netherlands, wet like in the UK 
From my in-car and other desiccants manuals I have learnt to not warm them up above 80°C (176°F) because when they get too hot, they lose their absorbing capacity.
The Eibos Polyphemus is probably worth a look after it finally ships (end of month, allegedly). It’s the one that rotates the filament while drying like a rotisserie. Are there any others which do that, or will it be unique in that respect? Seems like a really good idea. Also, it has a vent at the top for allowing moisture to escape. All good concepts, but these days you never really know how well it’s been done until real users report back.
As for me, I finally gave up on rinky-dink solutions and bought a blast oven from China. Talk about a huge chunk of metal! Built like a tank. Weighs 80 pounds. I hope to use it for annealing as its main purpose, but it’s the gold standard for filament drying.
Reporting back:
The blast oven works like a champ. It plainly uses PID for temperature control to hit the temperature target and then stick there. I’ve confirmed the displayed temperature is an exact match with what I measuring using my own independent temperature probe inserted into the chamber. No observable hysteresis. I’m happy with it. The only limitation I’ve run into, as I’ve mentioned on some of the other filament drying threads, is that the make-up air is drawn from the ambient environment, which ultimately limits how well it can dry in absolute terms. I’m confident this will be overcome fairly soon.
Meanwhile, I had a look at Sovol’s new filament dryer. My god, I can’t believe it ever passed any kind of product safety review. For levity’s sake, have a look at the description. I even highlighted the obvious problem!
Anyone see the problem here? Hopefully everyone? Let’s recap: the user can only set the drying temperature to between 40c and 70C. If you buy this device, that means that the range you want to dry filament at. Not higher. Not lower.
Problem #1: The safety feature that it brags about having is that it will turn off if it detects the temperature has reached 130C. Hello? Are you kidding me? The filament this was designed to dry will possibly (likely?) be fused together and ruined by the time it kicks off. Plus: will the plastic enclosure even withstand that kind of temperature? I hope sovol picked a suitable plastic to manufacture with.
Problem #2: It says it will resume heating when the temperature drops back down to 90C. WTF? Really? That is still far above the maximum possible target temperature, and it’s going to resume heating. Why? How does that make sense? I just don’t understand how China designs like this ever get put into production.
After looking at this, I will never buy a Sovol product. Ever. I don’t care what the reviews may be like for their printers or anything else they may make. I believe in the Zen proverb: how you do anything is how you do everything.
Yes, I see the problem. Another rogue Chinese company that can’t be sued for malfeasance in Western courts.
This product photo isn’t even real. Can’t everyone see that this is a computer rendering with very bad photoshop on top? Who falls for this kind of scam? I guess a lot of folks because it “Looks” cool. Sad. 
Add to that the fact that a number of their web pages are blank such as the Intellectual Property page and this gem of a marketing blurb. “Formidable Force” you say? No kidding. 
Keep pouring that Kool-Aid. PT Barnum was right.
Maybe so, but apparently the product is real enough that you can buy it on amazon:
and get it delivered in just two days.
And the amazon product listing makes the same claim as what’s on the official sovol website. Here it is:
It re-affirms that it’s the PTC temperature that’s being measured, rather than the interior air temperature (thank God), but still…
One of the amazon reviews raises another possible issue:
I don’t own it, so I can’t confirm or refute, so about all I can say is: caveat emptor.
Anyhow, imagine the PTC temperature went as high as 129C and then stuck there, never quite getting to 130C. Hmmm… What happens then? Is there no failsafe for that failure mode? Or the range of ones similar to it?
It’s got to be a problem with the education system or something in that region of the world. Or some kind of cultural aversion to pointing out problems in someone else’s design? Possibly some form of inattentional blindness? You know, over the years I used to be curious about the why of the failures in China QC. In that time, I’ve never heard a plausible explanation, other than just not caring. Maybe a team of anthropologists could figure it out. It would make for interesting reading. However, as of today, I think I’ve crossed the threshold into no longer caring why. It just is. It wouldn’t matter if we could buy elsewhere, but it’s all been handed over. There is no elsewhere.
A you just know that this went through thorough U/L testing. 
Unfortunately, it’s going to have to take something like an infant killed in a house fire by these rogue Chinese sellers on Amazon before congress takes any action. We learned nothing from the Lumber Liquidators Chinese formaldehyde scandal of 2015.
I bought a previous version 3D Printer Filament Dryer, Sovol SH01 Filament Dehydrator Spool Holder, Dry Box for Keeping Filament Dry During 3D Printing, Compatible with 1.75mm, 2.85mm Filament and PLA PETG TPU ABS Material : Amazon.co.uk: Business, Industry & Science I left the one star review. It looked nice, but that was about all.
I had an eibos dryer, which i thought was worse than the solvol, more awkward to fit the spool, etc, but at least it worked. Not much room for silica gel, however, but at least it almost did the job (except sometimes a spool would not fit, and it melted glue in cardboard spools!). I may rip it apart and make a different case.
fwiw, I think it is a bit daft drying a whole spool of filament, when maybe you only need to print a few metres of it. Then, because it takes so long to dry it, you need a special box to keep it dry. Afaik, there is only one consumer marketed dryer that dries the filament as it comes off the spool, and that price is far more than many will pay - Drywise In-Line Filament Dryer. However, a DIY version is perfectly feasible.
When I was using my ender 3, I had a short heated tube which I passed the filament through on the way to the printer. I convinced myself it made an improvement. If I thought it was worth my energy, then a small vacuum pump, a heater and silica gel/or dehumidifier, a temperature and humidity controller would be the way to go. This stuff is cheap from Aliexpress/elsewhere.
Hi there! I was planning to buy this FixDry, but noticed in the specs on their website that it can hold up to 195mm diameter spools. All Bambu (and Hatchbox for that matter) are 200mm. Did you manage to squeeze it there? Do you think it is still ok filament dryer? Thank you!
Looks like a great solution after all! Can you fit 200mm spools in there? Like Bambu filaments? Thank you!
Just my personal opinion, but I wouldn’t recommend the fixdry. the heat is injected through the center of the spool, and I found there’s a tendency for it to overheat the inner windings and melt them together. IMHO, It’s better to find a dryer which is larger, so that the heat is spread more uniformly from a distance. This is also what the bambu wiki recommends, btw.
That looks so much like an old computer tape drive with the twin spools like that.