|
Thread Number: 31148
Which is more energy efficient? |
[Down to Last] |  |
| Post# 470318 10/19/2010 at 13:37 (4,930 days old) by kindalazy (toronto) | ||
|
I was just wondering which is more energy efficient when drying clothes: drying on higher heat for a shorter amount of time, or lower heat, with a longer amount of time? | ||
|
| Post# 470324 , Reply# 1 10/19/2010 at 14:09 (4,930 days old) by Iheartmaytag (Wichita, Kansas) | ||
I don't have the actual numbers | ||
| Post# 470333 , Reply# 2 10/19/2010 at 14:53 (4,930 days old) by qsd-dan (West) | ||
 | ||
Post# 470334 , Reply# 3 10/19/2010 at 15:00 (4,930 days old) by DADoES  (TX, U.S. of A.) |
||
 I'm thinking lower temp, longer time should be more efficient. There's less differential on the target drum temp vs. the ambient airflow temp, so the heating source doesn't have to work as hard to hit the target. The power use from increased run-time of the drive motor likely doesn't surpass what's cut from less heating. Some electric dryers may also have dual heating elements and run only the lower-wattage element at lower temp settings. | ||
|
Post# 470337 , Reply# 4 10/19/2010 at 15:06 (4,930 days old) by joe_in_philly (Philadelphia, PA, USA) |
||
If it is a vented dryer, and the house is currently being heated or cooled, then all the air the dryer discharges outside will have to be replaced from outside air and heated or cooled.
I imagine there are a lot of factors at play in the efficiently equation, such as the amount of air displaced by the dryer, the dryer's source of heat, the outside air temp, the fuel and efficiency of the equipment used to heat/cool the house, etc. | ||
|
Post# 470841 , Reply# 5 10/22/2010 at 09:25 (4,927 days old) by BrianL (Saddle Brook, New Jersey) |
||
Well if electric is more expensive than gas, I would think longer but cooler dry times would be more expensive, including the additional wear on the drive motor. Plus the clothes are tumbling for a much longer period, especially over time. Rollers, felt, clothes, & motor will all see more wear I think. I have never had any problems drying anything on high heat, if the material allowed for it.
| ||
|
Post# 470848 , Reply# 7 10/22/2010 at 10:13 (4,927 days old) by Toggleswitch (New York City, NY) |
||
A typical electric American-dryer uses about 2.5kwh for a large load of clothes, according to Consumer Reports magazine.
If we were to look past the additional 600w motor's power-draw over a longer period of time, and had sensors to stop the machine when the load was (at the same level of) dry, I'd say the energy use either way (high or low heat) is so close that it does not have a truly measurable impact on one's monthly bill. High heat does fade darks and potentially leads to shrinking. (But then again when I was 10kg/25 lbs. lighter in weight, was a "perfect" (shrunken) medium in cotton tops/shirts. LOL SO for me shrinking was needed and expected. Wasn't there some feeble attempt to run/sell a dryer for 12 hours (overnight) at (or just above) room temperature to get it an "A" energy rating? Was that the UK or the European Union? My full-sized electric dryer, by necessity, runs its heating element on 110v (no 220v available or existing in my apartment) and thusly heats at 1,250w instead of 5,000w (@ 1/2 rated voltage, 1/4 the wattage). When I multiplied it out based on the extended drying times, the total KWH used was still very close to 2.5KWH per load. In many markets in the Untied States a gas dryer can cost only 1/3 of what it cost to run an electric one. (Barring hydro-electric markets and parts of the south first getting gas and paying royally for that infrastructure). | ||
|
Post# 471004 , Reply# 9 10/23/2010 at 16:01 (4,926 days old) by Frigilux (The Minnesota Prairie) |
||
My new Frigidaire dryer has a cycle called "Line Dry", which is supposed to mimic drying clothes outdoors, with only a little added heat. Have never tried it, because I have an actual clothesline to use.
The manual claims it's a very energy efficient, but long, cycle. Maybe I'll have to try it once just to see how it works. Frankly, I think it's hard on the clothes to have them tumbling around for several hours. | ||
|
Post# 471049 , Reply# 10 10/23/2010 at 21:43 (4,926 days old) by combo52 (50 Year Repair Tech Beltsville,Md) |
||
DRYER POWER CONSUMPTION
Running a full size American electric clothes dryer for 60 minutes or more with a full load of cotton clothes 12-15 lbs dry weight will use close to 5KWs worth of power when spun in a standard TL washer. Running on lower temperatures will save a small amount of power. Running a 240 volt dryer on 120 volts does cut the heat down to 1/4 and will cause the dryer to run about 3 times as long as when operated on 240 volts. Doing so will save about 15% in total power use, remember the early 1960s GE dryers with the economy button. This is probably what Frigidare is doing with the line dry setting.
| ||
|
Post# 471286 , Reply# 11 10/25/2010 at 09:34 (4,924 days old) by Toggleswitch (New York City, NY) |
||
|
LOL yah but the 5,000 to 5,200 watt heater in not on constantly. It is on nearly full-time in the beginning and cycles "on" less and less as the clothes dry.
So how can a 5,000 watt heater used for one hour INTERMITTENTLY be anywhere near 5kwh? My dryer is vented Gabriele. I may be wrong, but do remember multiplying out 2.5 kWh by $0.18 per KWH to arrive at a cost of electric drying at $0.45 per load in my area YEARS ago. | ||
| Post# 471287 , Reply# 12 10/25/2010 at 10:09 (4,924 days old) by LordKenmore (The Laundry Room) | ||
"My full-sized electric dryer, by necessity, runs its heating element on 110v (no 220v available or existing in my apartment) and thusly heats at 1,250w instead of 5,000w (@ 1/2 rated voltage, 1/4 the wattage). When I multiplied it out based on the extended drying times, the total KWH used was still very close to 2.5KWH per load."
Toggleswitch/anyone else who might know: Is the ability to run a dryer at 110v something any dryer can do? And is it hard to adapt the dryer? | ||
| Post# 471288 , Reply# 13 10/25/2010 at 10:11 (4,924 days old) by LordKenmore (The Laundry Room) | ||
|
"Frankly, I think it's hard on the clothes to have them tumbling around for several hours."
You might want to retract that, Eugene. I can imagine top load die hards around here who might have copied your comment to use (possibly after twisting a bit) for the next time a front load vs top load fight, er, discussion gets started! | ||
|
Post# 471289 , Reply# 14 10/25/2010 at 10:41 (4,924 days old) by Toggleswitch (New York City, NY) |
||
|
Quote: Is the ability to run a dryer at 110v something any dryer can do? And is it hard to adapt the dryer?
My conversion takes place in a custom-made extension cord itself. It is a non-invasive (to the dryer) procedure. The dryer's cord and plug and innards remain intact. I used: 110v MALE plug, industrial duty. Heavy duty air-conditioner extension cord, with a 20amp capacity. (Male and female ends cut off!) Standard 220v North-American dryer outlet with 4 prongs/wires. The green (ground/earth) from the wall (the plug) goes to the ground of the dryer receptacle The hot wire (black) from the wall (the plug) goes to the "hot" of the dryer that runs the motor, timer and lights. HERE IS THE TRICK! The dryer outlet is fed the NEUTRAL instead of a second hot to the wire that feed the heater (Would be black or red and normally "the other" hot leg). So I recommend that the dryer plug/cord (flex-cord => UK) be changed to the four (4) wire wire/prong type, if not already present. This ensures legal and proper grounding at 120v operation. My dryer has "auto-dry" but is NOT the electronic sensor type. It is time-temperature based. So I MUST use the "LOW" heat setting. The timer only moves when the heater is off (i.e. thermostat satisfied) when auto-dry is selected. I can only use ONE timer setting--the barest minimum auto cycle where the heat just turns on. Personally I'd say a sensor system is more a prime-candidate for conversion to 110v. Write to me offline with any questions. The beauty of my system (don't I just LOVE me? LOL) is that the dryer remains ready for ordinary 220v operation at any time. | ||
| Post# 471301 , Reply# 15 10/25/2010 at 12:02 (4,924 days old) by dyson2drums (United Kingdom) | ||
 | ||
| Post# 471347 , Reply# 16 10/25/2010 at 14:26 (4,924 days old) by dj-gabriele () | ||
|
My dryer is vented Gabriele. I may be wrong, but do remember Sorry but that was not what I was asking. I meant, if possible, using a watt-meter or else, standard test or such, to measure the actual energy use and the weight of the load being dried | ||
|
Post# 471441 , Reply# 17 10/25/2010 at 22:11 (4,924 days old) by combo52 (50 Year Repair Tech Beltsville,Md) |
||
|
DRYER POWER CONSUMPTION
Hi Steve it was fun seeing at the wash-in the other week. I think your 2 1/2 KWs is probably about the average power consumption most dryers will use drying a load when you average many different heavy and light loads. I was using a heavy load of cottons 12-15 pounds dry, spun in a TL washer. WP & SQ dryers have a 5400 watt element in them and the motor takes at least another 400 watts of power if not 500 watts. So actually you are close to 6000KWs of power draw, and such a load will cause the heater to say on 45-50 minutes of a 60-70 minute cycle so it really will get close to 5KWs of power consumption for heavy loads to dry.
| ||
|
Post# 471494 , Reply# 18 10/26/2010 at 06:44 (4,924 days old) by logixx (Germany) |
||
Bosch still has the Nexxt dryer on its UK web site. It has a 2700 watts heater. The web site says:
WTB76556GB Capacity 10kg / 22lbs Consumption rates 1000rpm: - Time 124 minutes - Energy 5.72kWh This is for a full load of medium-thickness (think kitchen towels) cotton items. Alex CLICK HERE TO GO TO logixx's LINK | ||
| Post# 471496 , Reply# 19 10/26/2010 at 06:49 (4,924 days old) by LordKenmore (The Laundry Room) | ||
|
| ||
| Post# 471506 , Reply# 20 10/26/2010 at 07:44 (4,924 days old) by Iheartmaytag (Wichita, Kansas) | ||
|
My original reply in post #470324
Was that it was more than likely six one half-dozen the other.
Logically I still stand by the statement as it comes down to the amount of work that needs to be done. The clothes are wet to a certain point. I am going to use a load of towels as an example. You can dry them by immediately blasting them with high heat which leads to rapid evaporation as the clothes heat up and dries slightly quicker. or you can turn the heat down and the process takes longer. In any case the heater is going to have to be on and produce equal amounts of BTU over the cycle to accomplish the same amount of work. It can be on high for 30 minutes, or low for 60. If low is 1/2 the power consumption it is still taking twice as long. Take for example a pan of water. You set it on the stove top to boil. You can turn the stove on High and it is boiling within a few minutes, or you can turn it on low and it takes longer. In the long run, it still required the same amount of BTUs to bring the water to boil. My theory may be off, but I will stand by my ignorance. | ||
|
Post# 471511 , Reply# 21 10/26/2010 at 09:07 (4,923 days old) by Toggleswitch (New York City, NY) |
||
|
| ||
| Post# 471530 , Reply# 22 10/26/2010 at 12:54 (4,923 days old) by Iheartmaytag (Wichita, Kansas) | ||
|
I'm sorry Toggles | ||
|
Post# 471599 , Reply# 23 10/26/2010 at 22:23 (4,923 days old) by toggleswitch (New York City, NY) |
||
|
| ||
| Forum Index: |
| Other Forums: |
|
|
|
|
|
Comes to the Rescue!
