Vintage Kenmore dryer seen at VOA

[retropia]

I was curious if anyone knew the year of this Kenmore dryer I saw today at one of our Volunteers of America. I don't believe I've ever seen one of these before. Sitting next to it was a newer Maytag washer; no matching Kenmore washer, alas.

The picture quality isn't great - cell phone photos.

 

[retropia]

Model number

I took a snap of the manufacturer's plate. It looks like the number might be 110.720BB--W

It's an interesting control panel because of the dial. It's not a traditional electro-mechanical timer, correct?

 

[qsd-dan]

1972

 

[kenmoreguy64]

Dan is right - a 1972 800 series.

 

[combo52]

1972 KENMORE DRYER

Ted and I just picked up the same dryer in harvest gold and gas this past Saturday it looks really good in gold. It is just a regular electro mechanical type control system it also has 2 1/2 hour wrinkle guard and electronic sensor dry its a good dryer you should grab it if you can. This gas one would I have could be available also.

 

[retropia]

Wrinkle Guard

So how does this Wrinkle Guard work? Does it really work?

Could you, say, put permanent-press dress shirts in, set the dryer, and come back after an hour or two and the shirts come out wrinkle-free and not baked?

 

[DADoES]

 
No, it doesn't work that way. Wrinkle Guard comes into play at the point a drying cycle is finished and the machine would otherwise shut off. If the door isn't opened (to remove the clothes), the dryer will tumble the clothes (without heat) briefly (typically 20 to 30 seconds) every few mins (typically 5 mins) to keep them mixed-up and not sitting crumpled and stationary in the drum. The end-of-cycle signal typically triggers at the end of each tumble period as a reminder to unload.

Different brands/models have variations on the process, how long it runs and their name for it (Wrinkle Guard, Finish Guard, Press Guard, Wrinkle Free, Anti-Crease, etc.). Some tumble continuously for a given period of time (20 to 45 minutes, whatever) instead of intermittently. Some tumble continuously for a while (10 to 20 mins maybe) then change to an intermittent tumble. Fisher & Paykel topload dryers go for 23.375 hours (255 cycles of 5 mins pause and 30 second tumble).

 

[alr2903]

Keep in mind 1972 clothing/textiles were often 90 to 100% polyester, so yes wrinkle guard worked pretty good back then. It was not the most comfortable clothing always kind of scratchy, and generated static cling. Washing these fabrics probably caused people old enough to remember them, to be "softner abusers". It was this generation of some of the ugliest clothes ever made, that prompted appliance mfr's to add all the Knit/delicate, PP cycles to even BOL models. alr2903

 

[retropia]

Learning more about Wrinkle Guard

I appreciate this information. Wrinkle Guard sounds like a handy feature that I do not believe is on our 10-year-old Kenmore/Frigidaire front-loader set. It has a "timed dry" of up to 90 minutes, which I believe runs continuously at whatever heat setting you select, until maybe the last few minutes when it switches to air-only.

The other choice is an "automatic dry" setting, which I'm guessing runs on a humidity sensor. It doesn't give a timed setting, but instead has "towels" as the longest setting, and "damp dry" for the shortest. Right before it shuts off it says "wrinkle rid" on the dial, but all that means, I think, is that it switches to air-only for the last few minutes of the run.

So let me see if I understand how this 1972 Kenmore might work. Could my permanent press shirts be thrown in, and the dryer set at a timed run of 60 minutes using the electronic sensor and low heat setting?

Then, let's say the sensor senses that the shirts are dry after 15 minutes. Would it then switch the temperature from low-heat to air-only for the remaining 45 minutes of the 60-minute cycle?

Then would the Wrinkle Guard feature kick in after the end of the 60 minutes, thus it would tumble for a few seconds, intermittently? Would the Wrinkle Guard do that for up to 2-1/2 hours after the 60-minute cycle ended?

Am I understanding correctly how it works?

 

[DADoES]

 
Sensor dry cycles are separate and distinct from timed dry. There is no specific time setting involved when using sensor dry. The cool-down phase begins immediately upon the clothes reaching the set degree of dryness. Perm Press cycles, whether by sensor or by time, typically have a 10-min cool down. Regular fabric cycles typically have a 5-min cool down. Dryers that have separate cycles for Regular and Perm Press, whether timed or sensor, the only difference between the two cycles is usually the length of the cool down, and in most cases the Wrinkle Guard function is part of only the Perm Press cycle.

So in your scenario, the machine would run for 15 mins at low heat, 10 mins of air-tumble to cool down, then if the clothes aren't removed, Wrinkle Guard comes into play for however long it lasts.

To further clarify sensor dry (auto dry is a more correct generic term), it can work primarily either by temperature or by true moisture sensor.

If by temperature, the typical control method is that the timer does not advance while the heat source (electric element or gas burner) is on. When the target temperature is reached per the machine's setting (low heat, medium heat, high heat, whatever), the heat source turns off and the timer begins advancing. When the air temperature inside the drum drops a bit and the heat source turns on again (like an oven cycling on/off to maintain the set temperature), the timer turns off. This heat-on-timer-off/heat-off-timer-on process repeats until the timer runs-out the operating time that was engineered into it for the selected dryness level. When the clothes are wet at start of the cycle, moisture keeps the air temperature down, so the heat runs longer and more often to reach and maintain the target temperature and the timer runs less. As the clothes dry, moisture evaporates, the air stays hot longer so the heat runs less to maintain the target temp and the timer runs more. Thus, the dryness level of the clothes is determined indirectly by the air temperature.

True "electronic" moisture sensing uses a pair of metal bars inside the drum. Wet/Damp clothes brush against the bars while tumbling. Moisture in the clothes completes a low-voltage electric circuit between the bars. An electronic control stalls the timer when moisture is sensed, and runs the timer when moisture is dissipated. Wet clothes cause more stalling and less running. As the clothes progress toward dryness, there's less stalling and more running. Note that the timer can be either a mechanical dial or an electronic control board, but the effect is the same.

Moisture sensing is by nature more accurate and consistent than temperature sensing. The temperature setting is a large performance factor on a temperature-sensing auto-dry machine, of course. Temperature should "match" with the type of load. Running a load of jeans or heavy towels at low temperature at the "Normal" dryness level on a temperature-sensing machine, the load may not come out acceptably dry. Running the same load in a moisture-sensing machine, it probably would as the electronics are more able to adjust accordingly. Advanced sensor systems with electronic controls can incorporate both temperature sensors and moisture sensors into program algorithms for better performance.

 

[kenmoreguy64]

Let me try to explain the WG and the sensor dry

There is an auto-dry cycle, a timed cycle, and if no temperature selector, an air cycle. In Kenmores, you can't use timed dry AND sensor dry both, it's one or the other.

If you choose to used a timed dry, the dryer is going to run like any timed cycle. It may shift temperatures if using Soft Heat, but other than that, the sensors aren't involved.

The auto-dry cycle is separate, and works fully dependently on the drum sensors, (or the thermostats in the case of a Fabric Master dryer). If you set dryness in the middle, between 'more dry' and 'less dry', the dryer will comply with whatever that setting equates to. Soft Heat may or may not be involved with this cycle too, depending on the model. The dryer however will run for however long it takes to reach the level of dryness that you select.

So, it's either an auto-dry cycle, or a timed cycle, but they are completely separate.

The Wrinkle Guard is usually the final phase of the Auto-dry cycle. In some dryers the WG runs simply tumbling with no heat for 30 or 45 minutes. In others, tumbling is started and stoped by way of a pulser in the timer to move the load before wrinkles set in, followed by a buzz every time the motor stops. Again, this is usually found at the end of the automatic termination cycle.

The dryers that turn themselves on and off for brief tumbling have caused more than one load of laundry just by doing that, lol. Ours, until it's timer got noisey, came on a couple times when I was in the laundry room cleaning the cat's litter box - scared the bleepity bleep out of me and caused me to drop the cat's deposits on the floor. No doubt I'm not alone in the "the dryer startled me" department.

Gordon

 

[kenmoreguy64]

Pardon me Glenn for saying a lot of what you did...I was writing while you were I believe.

Modifying one thing that Glenn said just a bit -

The cool-down does not necessarily begin immediately after clothes reach a selected dryness. This may happen in some, but in my 1986 Kenmore 70, when the level of dryness is reached, or a large degree thereof, the timer motor comes on (by completion of a circuit through a thermostat) and begins advancing the selector toward the 10-minute cool-down. However, until the timer gets there, the heat continues to cycle on and off as usual.

Gordon

 

[retropia]

Learning more but still confused

Now I know that auto-dry and timed-dry are separate on the 1972 Kenmore, and that helps.

I think part of the reason I'm still confused is because the auto-dry setting on our modern Kenmore doesn't seem to act any differently than the timed-dry. The only difference I can see is that the cool-down cycle seems to run longer on auto-dry than on timed-dry. Maybe the auto-dry doesn't work correctly on our dryer?

I attached a photo of the control panel. It doesn't have settings like "hard dry," "medium dry" or "soft dry." Maybe those selections are only on the older Kenmores, like the 1972 model?

If I'm understanding the description of how auto-dry works, then I should be able to put a load of wet jeans or towels in the dryer, set it at low heat, set the timer dial for delicates/permanent press, and the timer will shut off and on as needed, allowing the heating element to cycle off and on, until the items are dry? It would run for as long as it needed to get the items dry?

If we set the temperature at high heat, it would operate the same way, except it would take less time overall, because when the heating element came on, it would be at a higher temperature, correct?

That isn't how it would work with our dryer, though. In the above scenario with low-heat, the dryer would run for about 10 minutes at low-heat, then another 5 minutes with air-only, then shut off. The items wouldn't be dry. At the high-heat setting, they would be dryer, but still not completely dry.

I do appreciate the education I'm getting here!

 

[alr2903]

Retropia, I think the best answer is, your machine will do better if you select the right heat for the fabric, as Glen stated extra dry selected, plus low heat selected, would probably end up with damp towels in a temp. sensing machine, in a machine with sensor bars, chances are they would be closer to dry. I think selecting the correct temp/fabric, is part of the process. You also have to consider that towels would be best "bone dry", with that in mind you would want a percent of moisture left in loads of underwear, and socks, this trace of moisture, is designed into the cycle as Glen and Gordon explained to protect elastic and avoid shrinkage. When in doubt or drying a pair of expensive lined drapes, most people would select a lower temperature and use a time cycle for less than they estimate and check frequently, since you would probably plan to rehang the drapes slightly damp. To test your dryers auto dry, run 6 to 8 towels only on regular heat, timer set to "towels". If your towels are not dry when the dryer stops, i would check the vent for lint blockage, If its not blocked, call for service, or use the time cycle. Auto dry works best with many items of the same fabric weight. Make sure you clean your filter. alr2903

 

[DADoES]

Retropia,

Assuming the pic above is a shot you took of your dryer, I do see the description "Electronic Moisture Sensing" in the list of notable features on the panel. It has a mechanical timer dial, so wherever you choose to set it in the range of the Automatic Dry cycle, it does turn clockwise as the cycle runs, ending at the Off position as shown in the pic, yes? The moisture sensing mechanism functions (or *should* function) as I described above -- when moisture is present across the sensor bars, the timer is stalled from advancing.

Now, since this is a mechanical control (although coupled with a moisture sensor), the timer MUST physically advance to Off before the dryer shuts off, even if a completely dry load is run. Load in some dry towels out of your cupboard, set the dial at Towels, Regular, Delicates, Damp Dry ... whichever ... and the machine will run until the dial gets to Off. Being that the load is already dry at the start, it will move along as fast as possible (no stalling for moisture), but it must run for whatever is the requisite time period ... roughly the same as the equivalent dial arc on the Time Dry cycle.

That's the trick that comes into play ... the fact that this is a mechanical timer. The speed of the timer mechanism is engineered along with the range of settings on the dial, the appropriate temperature, and the average stall/run effect of the moisture sensing process, so that when a wet load is run (a given sort of fabric at the designated temperature AND the designated setting on the timer dial), the load will be (should be) properly dry by the time it gets to Off. If you find that a particular kind of load is consistently either too dry or not dry enough at the designated settings, you can adjust for it by altering the settings ... increasing/decreasing the dryness setting on the dial and/or the temperature choice until you get the results you want.

As alr2903 explains, your dryer working as intended depends on choosing both the designated temperature and the designated setting on the Automatic Dry cycle for the load being run. It's not realistic to expect a load of towels or jeans to be fully dry when run at the Low temp setting and on the Delicate dial position. If you want to run jeans at low temp to avoid high-heat exposure, you'll have to set the dial more toward the Towels end of the range.

Dryers with fully electronic controls (no mechanical dials) in some cases (NOT necessarily all cases) may be more forgiving with mismatched settings ... such as running a load of jeans at Low temperature and still turning them out properly dry. The moisture sensor mechanism coupled with a mechanical dial, it typically can only control whether the timer runs or not, and there's a physical limit to how long it can run or must run until the dial gets to Off. However, an electronic control board can be programmed to count the moisture "hits" on the sensor while at the same time keeping track of how long the machine has been running and also monitor the air temperature. Thus if heavy jeans are dried at low temp (delicate), the control board may notice that there are still a lot of hits on the sensor even though the cycle has been running what would be the usual time (for a delicate load), and allow it to continue running as needed until the moisture goes away.

 

[retropia]

Learning More

Yes, that is a photo of our dryer's control panel, and yes, the auto-dry timer advances clockwise until it ends at off, exactly the same as timed-dry.

I do understand the need to select an appropriate temperature and run time for the type of laundry being dried. Mostly I've learned this because auto-dry never seemed to act much differently from timed-dry. The reason why I selected that example, of a heavy, wet load, being auto-dried at at low-temp for a short period of time, was to try to understand how auto-dry works.

If the temperature and/or humidity sensors have the ability to stop the advancement of the timer, and would do so more aggressively in my example, then it would seem my example would come out completely dry. It might have to run for an hour to do so, at the low temperature setting, but the sensors would stop the timer, as needed, to make it happen.

Except not? Maybe there's some limit in how long the mechanical timer can be stopped before it must advance again? The exception might be for an electronic control board, which could allow longer periods before the timer is advanced?

In the dry towel test, if I placed dry towels in the dryer and set the temperature at high, is it my understanding that under auto-dry the sensors would detect no moisture, thus switching off the heating element? So it would be air-only until the timer ran to off?

The one thing I'm fairly certain of is that auto-dry has never worked in our dryer (which we purchased new), based on what I'm learning here. The reason I say this is that the timer dial always advances at the same rate during auto-dry as it does during timed-dry. It sounds like the advancement time should vary during auto-dry, depending on the wetness of the load.

 

[retropia]

Ok, I think I get it

Re-reading Glenn's note, I see he says that there IS a physical limit as to how long a mechanical timer can run. I'm guessing that limit includes any delays caused by the temperature and/or moisture sensors.

Thus, auto-dry is only automated up to a point. I guess I was hoping for a single-button console that Jane Jetson might enjoy. The button would be called "Make It Dry." Pushing it would cause the dryer to make all of the necessary decisions. Jane doesn't have the time to make her own decisions, because she is rarely standing still ... those motorized walkways are always whizzing her about the house.

 

[DADoES]

 
All this assumes your moisture sensor is a typical mechanical-timer-type of system.

Regards to running dry towels, the heat will be active until the timer advances to the cool down phase regardless of there being no moisture sensed. Moisture sensing affects only the movement of the timer, not whether the heat circuit is active. The heat circuit is a physical part of the timer. If you turn it from Towels toward off, you should hear/feel a click at the point the cool down triggers (at Wrinkle Rid, perhaps), which is the contact for the heat circuit disengaging. For a Kenmore dryer with the Soft Heat feature, I believe there'd be another click preceding the cool down at which point the element wattage and/or the target temp is reduced ... but this model probably doesn't have Soft Heat.

There's also a minimum required time for the machine to run on Auto Dry, per the timer position. If you eyeball the distance on the Auto Dry cycle from a particular position (Regular, for example) to Off, then compare that to the Timed cycle, that'll give you an idea of how long it will run in minutes without any moisture sensing delays.

Maybe think of it this way: The timer always runs, unless the presence of moisture across the sensor bars stops it. Wet/Damp clothes literally have to touch the bars to complete the circuit between them to stop the timer ... so while the clothes are tumbling, touching and not touching the bars, the timer rapidly alternates between running and stopped. When the load is very wet at the beginning, the timer is stopped more than it runs. As the items progress toward and then reach dryness, there are fewer instances of sufficient moisture to complete the circuit across the bars, so the timer is running more than it's stopped.

The difference between moisture-sensing auto dry system and thermostat-controlled auto dry is that:

- Moisture sensing moderates the timer's movement according to the sensor bars, regardless of whether the air temperature has reached the target (such as 125°F for delicate, 140°F for medium, and 155°F for high).

- Thermostat-controlled moderates the timer's movement according to the temperature, regardless of whether moisture is present. This can pose a problem if the dryer is run in a very cold environment in that it may not reach the target temperature (due to moisture holding the air temperature down) until the clothes are well along to being dry.

It does sound as if your auto dry isn't working.

 

[retropia]

Thanks again

I appreciate the education about auto-dry and wrinkle guard. It's amazing the stuff I don't know about our appliances. I'll try to locate a repair person to look at our dryer and see if he can get the auto-dry working as it should.