I ran across this video a couple days ago. It's an excellent explanation of how thermostatic auto-dry works.
Thermostatic Auto-Dry
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I ran across this video a couple days ago. It's an excellent explanation of how thermostatic auto-dry works.
mark_wpduet
Well-known member
I use auto dry all the time. I usually turn it to normal unless it's a heavy load then I turn it to more dry.
Been using my 1973 Maytag DG407 for the past month, thoroughly impressed with its auto dry cycle. Even small loads of shirts come out perfectly dried and not over dried. Even large loads of towels come out perfectly dried as well.
It’s amazing what a simple double switch thermostat can do, essentially can accomplish the same thing as a moisture sensor but without the complexity of moisture sensors.
It’s amazing what a simple double switch thermostat can do, essentially can accomplish the same thing as a moisture sensor but without the complexity of moisture sensors.
rinso
Well-known member
Regardless of what old CU says, I have found my thermostatic auto dry dryers did a good job of attaining the right dryness. With the exception of my Maytag HOH dryer, I have found that current moisture sensing machines don't do well with small loads or loads that have been spun very well, but are still damp.
mark_wpduet
Well-known member
90% success for me.. I sometimes use normal and sometimes I have to use more dry.. Most loads are normal... It's a big load of heavy towels or jeans where I have to use more dry. If I use normal with those loads it will not be dry...which is what confuses me if it adjusts the time itself...why is there even a more dry option with auto dry if normal is "dry".... but I never use timed dry anymore
there have been a couple of times where I turned it to more dry, and before the dryer even got to cool down, I opened the check and everything was bone dry..
so for me, it's not perfect but if you get used to its ways it almost is
For the record. My duet had moisture strips inside and I feel they are equally matched because that wasn't perfect either.
Overall
there have been a couple of times where I turned it to more dry, and before the dryer even got to cool down, I opened the check and everything was bone dry..
so for me, it's not perfect but if you get used to its ways it almost is
For the record. My duet had moisture strips inside and I feel they are equally matched because that wasn't perfect either.
Overall
When I got my Maytag 511 washer and 410 dryer, I read the owners manual and it said on the dryer to set the your first load to less dry and if it is dry enough, use that setting from now on. I have set it that way since I bought it 1984 but I do notice the actual time a light load is sooner and a heavier load like towels will run longer before shutting off.
mark_wpduet
Well-known member
I wonder if it is auto dry why there's such a long variation on the dial?
-Less Dry
-Between less dry and normal
-Normal
-Between normal and more dry
-More Dry
-and look how FAR you can go even past "more Dry"
Oh, and why do images end up being the wrong orientation on this site with absolutely no way to rotate them?
-Less Dry
-Between less dry and normal
-Normal
-Between normal and more dry
-More Dry
-and look how FAR you can go even past "more Dry"
Oh, and why do images end up being the wrong orientation on this site with absolutely no way to rotate them?
<blockquote>Oh, and why do images end up being the wrong orientation on this site with absolutely no way to rotate them?</blockquote> This problem arose due to data coding in photos taken with newer phones that affects how they display related to which way the phone was oriented when taken. Robert, as I understand, modified the photo upload process to auto-rotate photos to the correct orientation but it sometimes doesn't get the orientation correct.
I always pull photos taken with my phone into my computer (either by emailing them to myself to the computer or connecting the phone to the computer via USB for direct download), edit on the computer to crop/resize and rotate if necessary (phone pics are typically much too large and AW shrinks them which can deteriorate the quality). They always display correctly when edited with old Paint Shop Pro 7, maybe it's too old to support the image metadata and removes it from the edited file so the uploading process has nothing for (mis)interpreting the orientation.
Assuming the orientation is seen as wrong when previewing a post, remove the photo(s) from the post, rotate via the editing function on the phone, and reattach to see if that makes it correct.
I haven't used a dryer with thermostatic auto-dry since the Whirlpool LDE7800. It was installed in an unheated/uncooled garage and the performance/accuracy varied widely related to ambient temperature through the seasons.
As stated in other discussions, my F&P SmartLoad is very consistent with moisture sensing across fabric weights and load sizes ... except for a set of towels that have been out during the past 18 years only for "decor." Washed a few times (with nothing else) for refreshing, the fabric/design throws moisture sensing awry, always leaving them damp regardless of the setting. The nap appears to be synthetic with the backing and trim heavy cotton which apparently results in the sensor reading only the nap.
Some thick, slow drying items will throw off thermostatic auto-dry, while synthetics will throw resistivity auto dry off.
Multi-layer, thick seamed items throw off both, but in different ways.
Thermostatic auto dry can struggle with certain towels. They contain a lot of moisture, but moisture doesn't evaporate quite as fast.
Thus, at some point, the evaporation rate slows down to the point the air going through the drum does not take as much moisture with it.
The temperature of it doesn't drop as much anymore, thus the timer advances more often.
Same goes with uneven items.
At some point, most of the item is dry. Thus evaporation is so low, the temperature in the drum doesn't drop low enough to stop the timer advancing.
The reason these systems do well with synthetics is that they have a way longer "base" drying time.
It's after all just timed drying, with delayed timer advancing based on load.
Sensor auto dry basically has 2 different ways.
As far as I understand, some US dryers only stalled a timer as long as the sensor bars could conduct any electricity across them.
More modern, electronic based controls however can sense the actual approximate moisture content down to a couple percent accuracy.
Some even apparently incorporate temperature data as secondary measures.
Those do well even with heavier items like towels as they check for actual moisture.
Synthetics however barely contain any moisture and just never sense as very damp.
Same with very small loads sometimes.
Thick seams might just never touch the sensor bars and run unregistered.
Though more a topic for Imperial, but now I'm wondering: I know certain high end true moisture sensing dryers temper the heat as the cycle progress.
Didn't some pretty old dryers do that as well? Kenmore/Whirlpool?
Weren't those thermostatic?
Multi-layer, thick seamed items throw off both, but in different ways.
Thermostatic auto dry can struggle with certain towels. They contain a lot of moisture, but moisture doesn't evaporate quite as fast.
Thus, at some point, the evaporation rate slows down to the point the air going through the drum does not take as much moisture with it.
The temperature of it doesn't drop as much anymore, thus the timer advances more often.
Same goes with uneven items.
At some point, most of the item is dry. Thus evaporation is so low, the temperature in the drum doesn't drop low enough to stop the timer advancing.
The reason these systems do well with synthetics is that they have a way longer "base" drying time.
It's after all just timed drying, with delayed timer advancing based on load.
Sensor auto dry basically has 2 different ways.
As far as I understand, some US dryers only stalled a timer as long as the sensor bars could conduct any electricity across them.
More modern, electronic based controls however can sense the actual approximate moisture content down to a couple percent accuracy.
Some even apparently incorporate temperature data as secondary measures.
Those do well even with heavier items like towels as they check for actual moisture.
Synthetics however barely contain any moisture and just never sense as very damp.
Same with very small loads sometimes.
Thick seams might just never touch the sensor bars and run unregistered.
Though more a topic for Imperial, but now I'm wondering: I know certain high end true moisture sensing dryers temper the heat as the cycle progress.
Didn't some pretty old dryers do that as well? Kenmore/Whirlpool?
Weren't those thermostatic?
mark_wpduet
Well-known member
I think overly large loads might throw it off too
Today I did 5 medium loads....one load had towels, one jeans and the others mixed...I made a point to choose "just above normal" for every load...Everything came out almost perfectly dry except for a couple of barely wet thick seams of jeans..but not enough to say, OK these have gotta go back in for a bit..Even the towels were bone dry
The problem I've had with auto dry is if I have an overly large load to dry...I have to turn it to more dry or it will stop before it's dry...I almost never have an issue turning it to normal with a medium load.. When I say "medium" load it would probably be a LARGE load for a standard TL washer.
I could have made those 5 loads 3 loads...but I like to break them up.. I feel like things just wash/dry better that way...plus I don't have a massive amount of clothes to fold or hang up at one time.
What's funny is ever since moving to FL the dryer always finishes way before the washer...Back when I had a TL washer it was always the dryer I was waiting for.
Today I did 5 medium loads....one load had towels, one jeans and the others mixed...I made a point to choose "just above normal" for every load...Everything came out almost perfectly dry except for a couple of barely wet thick seams of jeans..but not enough to say, OK these have gotta go back in for a bit..Even the towels were bone dry
The problem I've had with auto dry is if I have an overly large load to dry...I have to turn it to more dry or it will stop before it's dry...I almost never have an issue turning it to normal with a medium load.. When I say "medium" load it would probably be a LARGE load for a standard TL washer.
I could have made those 5 loads 3 loads...but I like to break them up.. I feel like things just wash/dry better that way...plus I don't have a massive amount of clothes to fold or hang up at one time.
What's funny is ever since moving to FL the dryer always finishes way before the washer...Back when I had a TL washer it was always the dryer I was waiting for.
rinso
Well-known member
DADoES, My favorite dryer of all time was my top-load F&P dryer. Even thought it was quite complex and fussy from an electronic & mechanical standpoint, I made a mistake by not including it along with the old Maytag HOH dryness sensor accuracy.
Reply #9
That feature was the Kenmore Soft Heat dryers in gas and electric in the early to mid 1960’s. Basically how it worked is it would start out with the full heat output and as the cycle progressed, it would gradually turn the heat down right before the cool down. The Kenmore Soft Heat dryers were mostly timed drying, even timed drying on those dryers was a form of auto dry since it would throttle the heat output once the outlet exhaust temperature began to warm up when items became more dry.
If you were to throw in a small load of towels in a Kenmore Soft Heat gas dryer for 40 minutes, it would first start out with the full 37,000 btu heat output. After the outlet exhaust temperature reached 160F, it would start to throttle the burner down since the evaporation process would begin to slow down, after awhile the burner would either be outputting 5,000 btus or would be completely off since there wouldn’t be a need to add additional heat since they would be completely dried.
That feature was the Kenmore Soft Heat dryers in gas and electric in the early to mid 1960’s. Basically how it worked is it would start out with the full heat output and as the cycle progressed, it would gradually turn the heat down right before the cool down. The Kenmore Soft Heat dryers were mostly timed drying, even timed drying on those dryers was a form of auto dry since it would throttle the heat output once the outlet exhaust temperature began to warm up when items became more dry.
If you were to throw in a small load of towels in a Kenmore Soft Heat gas dryer for 40 minutes, it would first start out with the full 37,000 btu heat output. After the outlet exhaust temperature reached 160F, it would start to throttle the burner down since the evaporation process would begin to slow down, after awhile the burner would either be outputting 5,000 btus or would be completely off since there wouldn’t be a need to add additional heat since they would be completely dried.
