Hypothetical question: Can't 110 volt dryer vents/ fan speed be cut way down?

[harpon]

Just musing on designs, because I've been looking at 110 v compact machines, and saw a couple of videos of machines in use.
What struck me tonight is that there's always still a quite active vent with forced air coming out the back. So I started to wonder- How much venting is actually needed? Don't 110 appliances usually draw no more than 1500 watts?

I started wiring up a spare Kenmore space saver in the garage I practically couldn't give away today to 110, after I searched replacement motors on ebay and noticed they were all 110v anyway. I went through this a bit a year or so ago with a small water heater, that I bought with both a 220 element and a 110, and learned that the wattage is cut to a fourth as much using the 110 element and wiring. So anyway, I got the Kenmore to power up the motor, with a 3 prong outlet wired to a standard grounded wall plug. But no heat- and since then discovered that the element has to be wired to 110 separately, which I'll probably do-

because as much as I'd like to get a little 110 compact dryer, I don't want to lay down the $300 right now when I've got a full size 220 already in the garage (I'm eventually hoping to have machines inside the house in the bathroom), AND while I have this already small sized machine that appears may be actually able to be converted. (Pictured below)

So anyway it struck me- if I only draw 1/4 of the 5400 watts of element with 110 volts, then the vent must likely be too large and moving too much air. Wouldn't it be better to cut the venting volume and speed down to 1/4, to retain as much of the little heating wattage the 110 offers?

And I recalled the videos for the new compact 110 volters- it seems there is still a large vent with a really strong vortex. Do you think that is necessary?
There's a youtube link to one below

How hot do these dryers get compared to full sized 220?
They - unfortunately I think- often have a full 20 minutes of cooldown at the end of their cycle- seems like a waste of time and power if unattended.

I'm wondering if I get the Kenmore element wired if I can also cut down the venting- maybe a cover with half the diameter cut out-

How is the air generated? Is it by the rotating drum?

Anybody with any experise or thoughts about dryer venting vs. element power operating temperature, and voltage?

Should we trust the corporate decisions, or will there be a better way?

 

[alr2903]

I used these small WP produced machines for years.   I would not alter the air flow.  They work well enough for the power they consume.  They have a blower just like full sized machines, maybe smaller.  They also have thermostats that measure the heat.  You need the airflow to pull the lint/ moisture to the filter.  This portable design has been in use for decades.  I did forget to clean the lint screen a few times by accident. with no noticeable change in cycle time.  The best tip I can give you is to do your wash loads in the order of what dries faster.  Lightweight fabrics and small loads first.   Dry your jeans and towels in the last loads.  Also wash more frequently so the dryer loads are smaller.  Good Luck.

 

[arbilab]

I've used one since 1984. I wouldn't alter anything. Stopping up vents/ducts makes the dryer take longer, not shorter. This building just had the repairman out because a 240V Maytag wasn't drying. The outside vent was clogged (the maint guy is unbelieveably lazy).

Yes jeans/towels and the like take longer @120V, most everything else finishes in 40min.

 

[davetranter]

Dryer conversion

Harpon, I have read your post twice, and can't be sure of your exact intent. A 220V induction motor will run at much the same speed at 110/120, but with much less torque available, so it may stall, or fail to start completely (and if it does, it will burn out in seconds (be warned)). the blower on most dryers is a fan on the end of the motor shaft, so (if the motor will run at all) airflow will not be much reduced. Strong airflow is good, as previous respondents have commented. The heating elements need to be examined to see whether there multiple elements, series connected, which could be re-wired in parallel (subject to wattage limitations), or whether a 'center-tap' could be connected.

Hope this helps

All best

Dave T

 

[harpon]

Sorry Dave- you're not getting it. The motor is obviously 110 volt- though I haven't confirmed it yet officially-

and I think a great many, if not most of the motors are 110-
220 is then used only for the heating element.

Plugged into a ground fault 110/120 v plug, it is powering up the unit- both the drum and blower- at normal operating speed-

So I've just been out in the garage taking the dimensions and musing about it-
My Spacesaver is taller, but some of it is more space for older controls, and then several inches deep than the new compact units- a standard 4 inch vent near the bottom of the back- I'm sure it weighs more than the new stuff- but it's here already at least!

since I got the idea yesterday- further internet research has confirmed the obvious- now the heating element itself has to be wired for 110 instead of 220-

with the unfortunate quartering of the wattage- the 5400 watt heating unit will then pull about 1350 watts-

the question now is- how many watts is the motor pulling?
I only have about 150 watts left before the 1500 level that most 110 v appliances are cut at(I'm specifically thinking of my oil filled radiators- which I most often hook to line level individual baseboard thermostats, and are all the heating I need in north florida.)

Obviously the unit should then run on a circuit all by itself- preferably a dedicated circuit, with a ground fault outlet- in a perfect world. It's going to pull about 1500 at least on it's own-

which brings me to my latest musings and speculations- specifically regarding mostly the venting speed, and possibly even the motor speed and power.

I'll probably tinker this still at some level- once the weather and my schedule clear a bit- I'll see then if the ground fault or the breaker then blows, with both the motor and reduced heating element power powered up together- Not expecting trouble though, while it took a couple of attemps to wire the plug to the right terminals on the 3 prong outlet- with some good 10 guage NM line between- the ground fault plug absorbed it well.- I wouldn't want to messing around on old circuits with fuses!

yet the problem remains- a much too powerful blower pushing what little heat the 1350 watts of 110 power will get outta the element- (which would last a lifetime I guess!)

So, without yet having any look inside, and knowing very little-

I'm guessing that the blower is also powered off the same motor-
is the air generated by a blower unit itself or from some kinda fins around the tub?

I've seen one picture that looks like a little blower unit-
is it run off the motor with a belt and a pulley- ??

if that's the case- perhaps a larger pulley and longer belt coiuld slow the airflow down- (I learned this bike riding!)

Another alternative might be to cut the power and speed of the motor- wouldn't cutting the power with a rheostat slow it all down? The element would obviously still need the full juice.

I'm not sure what the physics of the motor might dictate then- would the motor have the power to turn it all slower? Or would it stress it? Please don't naysay if you don't really know!

I think it would be great if both the speed of the blower and the speed of the drum were reduced- and it would definitely be a quieter unit-

but what is the more important at this point is simply slowing down the blower and the rate of the discharge of air only heated a quarter as much. Reducing the outlet would only collect more lint- but perhaps not at 220 volt levels.

I'm also wondering about LINT- What causes it? Is it more influenced by temperature or by the speed of the tumbling?

The lint is supposed to be trapped before venting, but the vent obviously has to be cleaned out- because of lint in the vent air and I see pictures of people venting UP? Doesn't that make less sense? (see middle photo in ad link below)

Is there a LINT expert in the house?

Is there any reduction in lint at lower temperatures or lower tumbling speeds?

Pardon Our Interruption...

 

[harpon]

Ooooooh. INSPIRATION!

Another idea!

What if I can simply SHROUD the blower unit itself?

That won't itself result in any more lint buildup in the vent pipe I think- it would only reduce the airflow and allow the temps to increase in the unit as it operates-

This may make the idea more viable!

 

[harpon]

Okay looking at this all some more-

I've been perusing replacement motors on ebay- all 110- 120 volt and all seem to run at 1725 rpms- 5.5 amps is thrown out there a lot-

not sure how that relates to watts and how much wattage the motor pulls

below is a link to a motor and blower overhaul kit-

So it's obvious that probably some variance between the motor speed and blower velocity could be achieved with pully sizes and varying belt- may be difficult in practice- not sure at this point-

looks like the motors have shafts on both sides-

one for tub, one for blower ? I guess.

Also some altering of the blower fins could obviously cut the velocity as well-

still think the shrouding or partial diversion of blower stream may be the most practical and easily accomplished-

The tub isn't as much an issue because the spin drying isn't bad-
A lot of people say that cutting the wattage of the heating element 1/4 increases the drying time by 4- that doesn't make sense, because the spin dry aids drying even without heat- but certainly makes it all longer.

but what I'm interested here is maintaining more the reduced heat

I would still personally favor any machines designed to rotate slower and vent the lesser 110 heat not so quickly- but that's just me- I'm the same way with AC units-

Give me a slower blower whose noise doesn't drive me crazy all by itself!

Pardon Our Interruption...

 

[harpon]

Had some dinner and looking at this further-

So I see this motor (link below) and the blower wheel with fins is attached directly to the motor, and shrouded by a plastic assembly that directs the air-

So then if this is typical, there's little chance of "changing gears" or any pulley sizes to make the blower velocity less intense- bummer-

but it may be easy to baffle that- or make changes to the shroud to reduce velocity

It also maybe already answers a question I was forming-
Apparently their are already models in cases that look much like mine- Kenmore and I think I've seen Whirlpool- that come from the manufactures already wired as 110/120 volts-
so I was wondering- in the 110 models already out there for years-
1. Is there a different type of heating element?
And
2. Has any alteration been done concerning the vent velocity, to compensate for lower heat?
Knowing the corporate landscape, and obbsessions with the QUANTITIES of production, I'd be willing to bet that the answer to the second question at least is "no", and that the same motor and shrouds and blower fins are used whether the unit is sold as 220 volts or as 110-
Unfortunate-

and I'd be happy if someone with insider knowledge who knows for sure tells me differently.

Anyway- I've wasted enough time on it today- but enjoyed mulling it over-

if I get into the case- I'll report here what I find

Pardon Our Interruption...

 

[cfz2882]

motor

"split phase"motors as used in American dryers are not practicle to slow down because the centrifugal switch will not switch off the start winding and it will get hot.To reduce airflow through dryer,restricting the vent flow is the only easy way but could impair dryer performance by reducing the discharge of humid air from the drum and create an overheating hazard if restricted too much.

 

[harpon]

OK- good that tells me something- Thank you
I've been watching videos about it all on youtube

I think the way to go at this point may be just to get it running on 110 and see how it goes-

cutting down on the airflow would probably be practical, but I'm wondering if it's worth the risk-

I'm just speculating that with 11o power to the heating element- I don't think the upper temp cut-off thermostat would ever reach cut off temp-

I suppose the ultimate tinkering would be to find at what air flow restriction level that started to happen- and then backing off from that point.

I'm just amazed now that the blower is actually more "sucking" the air through the system and actually most near the outlet end of the line

 

[combo52]

Reducing the airflow for a 120 volt dryer?

Yes you could do this, BUT it will make the dryer use more energy, take longer to dry and likley cause problems with clogged vent systems.

You correctly figured out the a 240 volt dryer operated on 120 volts only produces 1/4 the heat, but the interesting thing is it usually only takes three times as long to dry a load NOT four times as long and the other end result is that you actually save about 15% total electrical consumption. This is because of the higher airflow compared to heat input.

The only reason to restrict the airflow was if you were very concerned about the amount of heated or cooled air you were sucking out of your home, and if this is an important factor for you you should locate the dryer on the porch or in the garage anyway.

Do note, there is no such thing as a 110 or 220 volt dryer, check the model# tag or the specs on the motor, heating element Etc of the dryers you are talking about. If you are using the wrong voltages in your calculations it makes you look very poorly informed.

 

[harpon]

I'm just using common terms 110 for 110/120 Volt and 220 for 220/240 volt I guess- I think the names have changed through the years-

the difference being whether one or two 110/120 volts wires are hooked to something

I see them advertised on craigslist and ebay as 110v. I guess they are more officially 120v these days-

I don't think a smaller airflow with a lower heat 110 machine or wiring will necessarily clog more- but a crude baffle might-
I'm just saying that with less heat going on in the dryer,
the venting probably theoretically doesn't have to be the same-

I'm still wondering about "LINT"-
Does it occur less in lower heat? Is it more a product of airflow and tumbling?
I'm just guessing the heat factor means more- but just guessing.

Anyone familiar with the "science of lint"?

Below is a video I found that's very comprehensive about the basic principles- and also demonstartes how the 110v motors are wired into the 220 circuit, and only the greater voltage used in the heating elements.

What I'd like to compare someday are the ducts and blowers and heating elements inside my own Space Saver machine- wired and sold as 240 v, with those units that look the same in every way and sold as 110.

Is ANYTHING different about them? I wouldn't be surprised if they have the same ducts, blower and even heating elements- I'm not talking about their wiring-

if they have the same blowers and the same ducts- it just seems to me that they could be made more efficient by retaining more heat with less air flow.

all I'm sayin....

 

[harpon]

Here's a 110 machine on my local craigslist:

and some pictures of it apart- but none of the blower or ducts- so go figure.
Cleared some garage space around the nachine today- and may take the back cover off soon- is I decide to wire it 110- I'd probably replace thechord with the really old 3 prong plug.

http://jacksonville.craigslist.org/ppd/4327357132.html

 

[harpon]

OK-

I'm not going to keep running all this into the ground- but may dredge it up as I tinker more.

Below is a link to the best discussion on LINT I could find on the net-

(I've only more got the feeling that the manufacturers are sort of avoiding the issue as it relates to this discussion of air flow and lower temps of 120 v power- and i suspect that's because the U.S. manufacturers at least may be not compensating for lesser power at all, in machines that are basically the same size and weught and with the same motor as the 240v models, and still just as heavy- I've come to feel that much of it revolves always to the end of selling lots of gasoline, but that's another weighty issue and discussion)

Anyway- as much as I'd like to get a newer asian 110 unit- and they are putting out a model that more like 21-22 inches deep instead of 16 or 17- I'm still enthused that the Space Saver I already have- and couldn't sell for even $40 last summer- actually has more space inside it's much heavier frame. So it's got some potential for 120 wiring- I may eventually convert the plug itself instaed of jumping it with the 3 prong to wall plug homemade rig-

Some of my thinking started more leaning to 110 volts when last month my other dryer melted the 240 outlet and almost set the garage stud on fire- I was fortunately right there as it started to blaze-

and I have to take some responsibility- I had heard some arcing on start-up- that I didn't realize realize could grow into such a problem- I first thought that perhaps a lizard had crawled inside the conduit and gotten fried- but a lesson to learn for sure- If you hear arcing from a high powered plug especially- don't keep running it!

I've replaced the fried plug and it's run a few loads since, but all this as I'm making plans and working to have machines in my bathroom inside the house and not the unattached garage- so I'm more fire-hazard conscious now-
Plastic DOES eventally start to burn!

Anyway- I'm stll thinking that lint may not even be such a problem at lower heat of 120 volts-

http://www.laundrytoday.com/index.php/business-mainmenu-29/lint/312-what-causes-lint

 

[harpon]

Done some research now-

here's my macine basically, the same cabinet ans size I think but sold as a 110/120v unit- it is 3.4 cubic feet otherwise- so larger than the asian units but much more expensive new- used ones ARE out there quite a bit I think, for much less- I paid $75 for this one two years back, and have seen them as low as $25 on craigslist

The link below is to the customer reviews- and the lowest rating from reviews seems to address this very issue- the most common complaint is low heat and extended drying time-

I'm just guessing that the blower and venting is the same as with my 220 v model- but hope I'm wrong. If it is though- it's just a bit stupid and could be easily adjusted to retain more heat-

There are also some specs listed here, and the 15 amp circuit is described as minimal- so I'm going to search around and see if I can ascertain whether there is indeed a different element or motor used. I'll bet the motor at least is the very same.

http://www.sears.com/kenmore-3.4-cu-ft-electric-compact-portable-extra/p-02684722000P?prdNo=1&blockNo=1&blockType=G1

 

[harpon]

I've got 120v HEAT going now!

It's still just jumped with my own 3 prong female to two prong 120 adapter- so I'm going to change the whole cord out when I get a suitable replacement- though I have lots of fresh NM 12g wire I could just wire to a plug- so that may happen- i think it would be nicer to have a normal looking heavy line

Yes, you have to jump the neutral central to the old second RED 240 terminal to close the 120 circuit on the heater coil-

And so I was a bit wrong on the coil- apparently they DO change the coil between a 120 v unit and a 240- generally going from 5 coils down to 3 in the 110.-

Yet I seemed to be getting some good solid heat off the 240 coil on 120, so I'm not planning to change t for now-

but I still think the blower fan and chamber are the same whether the model is sold for 120 or 240-

My idea now- if I find the unit not heating as much as I'd like- is to perhaps get another blower fan wheel, and at my convenience- simply drill some holes in some or all of the fans- that would surely cut the air velocity- and I could start gradually and do more later- depending on what kind of a job it may be- I haven't even opened up the blower housing at this point-

But I have noticed one thing- there seems to be ONLY ONE blower fan listed as a replacement- NOT a separate one for 240 and 120v models-

so that might be a corporate decision based on production levels that may be able to be tweaked easily to get more heat retention in the unit on 120 power-

there's also a HOLE manufactured into the top of the heating element duct, so that in fact all the heat is NOT being diverted through the tub, but being vented into the unit in general, and even may be raising the operating temp of the motor itself.

I may drive a piece of pie pan aluminum over it with some sheet metal screws.

anyawy- VERY ENTHUSED NOW! and glad I didn't yet balk for the asian unit

This is GREAT- I'm sure glad I couldn't sell it before.

I'm going to take some photos of it all sooon, so stay TUNED!

 

[DADoES]

 
That hole at top of the element box has been the case for *years*.  I've posed the question a couple times of why is it there and no one has answered so it remains a mystery.

 

[tomturbomatic]

When GE offered instructions for their full size dryers that were operated on 120 volts, they offered an air restrictor plate that was placed where the lint screen went, after the screen was removed, for drying Wash 'n Wear loads. The lint screen was not really needed since the fabrics did not give off much lint anyway. The air restrictor enabled the dryer to reach proper dewrinkling temperatures, 160F, for best no-wrinkle drying. It was the only type of load for which the temperature was important, but I have successfully dried perma press garments in 110 volt dryers and had them come out with no ironing, so the quest for higher temperatures in your compact dryer would not seem to be very important. If you let the dryer run past the point where the load is dry, the temperature will rise quite a bit for dewrinkling. I suppose you could paint the cabinet black and place it in the sun and run it or you could use it in the garage where it would be warmer and that would give slightly higher drying temps.

 

[harpon]

It's as much in my mind at least that it's just blowing the lesser heat right out of it- it's costing power and that costs me time and money.

If it were taxes being spent- people would hang for it- but it's just coprporations eating up your own income by not making an adjustment over something- choosing the easy way to put out something in both voltages without adjusting the parameters- and throwing the same parts into everything-

You'll just have to labor more to pay a bigger utility bill- climate concerns not withstanding. The drying time should not be solely dependent on the wattge of the coil- Whirlpool/ Kenmore has taken the easy way out by using the same set-up other than the coils, and the machines weigh a lot by more modern standards and so they still have greater transportation and shipping concerns.

TYPICALLY- as I've looked at heating elements- the ones specified for 120 volts are much more EXPENSIVE than the 240 volt wires- when they have less wire and coils in them- and generally on the same frames of their respective eras. The ducts and blowers are the same for both 120 and 240 volts.

I've got the machine wired now with a normal 120 volt plug, So I'm all set to try some clothes in it when I wash some- for now I've covered the hole at the top of the elewment vent with a simple piece of duct tape- but not sure it will last long.

I've tried to date the machine but got inconclusive results- I think it was made about 1978-80. It really wasn't very dirty inside- so had either been cleaned along the way, or used little.

I also thought of putting more screen mesh into the lint filter to decrease airflow sucked through by the blower, and that's another fairly easy thing to do-

For now I just need to see how it goes. I'm tinkered out for awhile now at least and just need to test it. I'm wondering how I could get some kind of temp reading inside the drum.

Sorry- no pictures yet- I was too busy working out the bugs, including taking the back cover off again unnecessarily one last time, when the dryer timer had simply reached cooldown and I was then puzzling as to why it wasn't getting hot - I knew I was punch drunk by then!

Below- these units are getting wider now- and the cubic feet is actually more than my Kenmore now- and at half the weight- I have to wonder....