1800 W is the same as another 1800 W

[Ponchik]

I was wondering, is the output of a 1800w hair dryer the same as a 1800w space heater?

To me it seems 1800w is still 1800w but I just can't see a hair dryer heating a room just as fast as a 1800W space heater.

 

[480sparky]

Perhaps because some of the 1800 watts in the hair dryer is the motor?

 

[George Stolz]

Yeah, but still...

Good question.

 

[hurk27]

A word of advice do not fall for certain appliances false ratings given to sell a product, hair dryers are one such product, it is more like 1250 watts max, if it was 1800 watts it would require a 20 amp plug on the end of its cord as NEMA/UL would not allow an appliance to pull that much load, about the highest wattage appliance we can find in the consumer market with still having a 15 amp rated plug is a 1500 watt portable electric space heater and while yes they do allow them they can find the weak link in any electrical system, also the instruction usually on the cord states that these high wattage space heaters are to be only connected to a individual branch circuit.

1800 watts is 100% of a 15 amp circuit as the NEMA requirements limit hair dryers to 1250 with a 15 amp plug, at one time 1500 and 1600 watt one were made but after a few fires and complaints it was lowered to match the limit the NEC allow for a breaker to be loaded to 80%, sure newer houses today have 20 amp rated bathroom circuits but NEMA has to keep the rules in place for the millions of homes that were wired back when 15 amp bathroom circuits were still being installed.

Vacuum cleaners and portable air compressors are the two other biggest electrical products that use this method of over stating its true load or output, I have a air compressor in my garage that claims it is 5hp rated but yet it has a 15 amp cord on it and pulls about what a 1hp motor would pull at full pressure.

Where they get these ratings is anyones guess, when lawn mowers did this back a few years ago they were finally sued over it but not sure of that out come as they no longer state the HP rating of the motor and use other deceiving methods, Audio amps and receivers was another area this was being done in, I had a receiver that claimed it provided over 1500 watts RMS to the speakers but only used about 250 watts from the plug so go figure.

 

[hurk27]

To answer the OP question I would suspect that the fact that a hair drier has a fan that will move more air I would expect it to heat a room faster than a small space heater of a true equivalent wattage if the space heater is radiant and or convection only or only has a low CFM fan, I have used the wifes hair drier a few times to knock the chill out of the bedroom as I keep my vents shut in the winter time as I sleep better with the room a little cooler at nite, but in the morning its a bare to get out of bed into a cold room.

I know my computer will make my office (converted bedroom) very hot and I have to open the window as it has a 1250 watt power supply two SLI Nvidia video cards 4 SATA raid 0 hard drives, and a quad core Pentium extreme processor, it can put out allot of heat when I get into high demanding graphic programs.

 

[Ponchik]

A word of advice do not fall for certain appliances false ratings given to sell a product, hair dryers are one such product, it is more like 1250 watts max,.......

That is true, the rating is not accurate. My wife's hair dryer is 1800watts but only draws 13Amps.

 

[chris kennedy]

1800W at what voltage, 125?

 

[Ponchik]

Perhaps because some of the 1800 watts in the hair dryer is the motor?

Yes some is in the motor, but that much to make a big diffreence?????

 

[Haji]

Check the ampere rating of both. Higher amperage will deliver greater heat output under the same voltage rating.

 

[K8MHZ]

I was wondering, is the output of a 1800w hair dryer the same as a 1800w space heater?

To me it seems 1800w is still 1800w but I just can't see a hair dryer heating a room just as fast as a 1800W space heater.

Actually, they are pretty close. One problem is that the hair dryer is not meant to stay on for hours on end like the space heater, so any tests have to be short. Also, you need to be in a small, closed room for an accurate comparison. The hair dryer will blow heated air much farther away which 'dilutes' it more with ambient temp air.

 

[K8MHZ]

Check the ampere rating of both. Higher amperage will deliver greater heat output under the same voltage rating.

That depends on the size and efficiency of the blower motors.

 

[K8MHZ]

Yes some is in the motor, but that much to make a big diffreence?????

I just tested an '1875' watt dryer.

Full draw - 13.00 amps

Motor only - 2.07 amps.

I would say the difference is significant.

 

[kwired]

Outside of any "marketing" strategies of marking it with some false value (but, usually some technical reason that makes it somewhat true) watts is watts.

Lets say we have a 1500 watt element in a space heater, this heater could have no fan and relies totally on convection to disperse heat, or it may have a small fan that moves air at a low velocity. It will still raise the temperature of a controlled environment a specific amount over a specific time.

The hair dryer may still have 1500 watt element, will likely be more density to the element (it creates the same heat in a smaller space), and will have a higher velocity blower to disperse heat. Point that at your wet head and it directs more of that same amount of energy toward one point over less time to accomplish a specific task. If you put it in same controlled environment as mentioned before with the space heater it should still raise the temperature of that controlled environment the same amount over the same time if it is the same wattage.

 

[Greg1707]

1800 watt is 1800 watts

1800 watt is 1800 watts

This question comes up a lot regarding different heating appliances. There are lots of advertisements for small heating devices that have extravagant claims of efficiency, effectiveness and power! As far as I know, 1,000 watts is 1,000 watts. That means any resistive heating device no matter how large, long or small that is rated 1,000 watts should produce the same amount of BTUs. This means the heater the Amish make and sell in the Parade Magazine produces the same heat as any other similar device.
If this is not the case I must be missing something?

 

[kwired]

This question comes up a lot regarding different heating appliances. There are lots of advertisements for small heating devices that have extravagant claims of efficiency, effectiveness and power! As far as I know, 1,000 watts is 1,000 watts. That means any resistive heating device no matter how large, long or small that is rated 1,000 watts should produce the same amount of BTUs. This means the heater the Amish make and sell in the Parade Magazine produces the same heat as any other similar device.
If this is not the case I must be missing something?

You are correct, watts is watts.

Those heaters you mention, as well as many others sell very well, because people do not understand the physics. I the infomercials you see they always have people mentioning "no heating bill" or "reduced heating bill". If your homes heating system is gas, of course, the gas bill will go down, you used less gas, your electric bill should have gone up though. Now if you are using the heater in only one room, you very well do still save some money, as you are only heating that room, or maybe you leave the rest of the home at a lower temp and only raise it in a single room where you occupy the most. By doing that you are "zone heating". Any electric heater will use the same in energy to heat that room to the same temperature, it does not have to be the one they are trying to sell you.

If you have a resistance electric heating system in your home, you may save some with "zoning" certain rooms and keeping others at lower temp, but if you have one of their units in every room and set each to same temp, you will save nothing, it should take same energy from your central system to do the same thing.

If you have gas central system and you put one of their heaters in every room, all set to same temperature, you will only save on energy cost if electricity cost is less than gas cost. This will not be true for most of the country. Couple years ago gas was high enough that many might have saved some money, today gas is lower and that may not be the case. I have not looked into specific rates recently, but have heard gas is much lower than it was a couple years ago in most places.

 

[K8MHZ]

This question comes up a lot regarding different heating appliances. There are lots of advertisements for small heating devices that have extravagant claims of efficiency, effectiveness and power! As far as I know, 1,000 watts is 1,000 watts. That means any resistive heating device no matter how large, long or small that is rated 1,000 watts should produce the same amount of BTUs. This means the heater the Amish make and sell in the Parade Magazine produces the same heat as any other similar device.
If this is not the case I must be missing something?

1000 watts = 3412.142 BTU/hr.



http://rapidtables.com/convert/power/Watt_to_BTU.htm

 

[K8MHZ]

Just for math fun

I have a 9000 BTU (2637 watt equivalent) gas space heater. It costs about 10 cents per hour to operate.

I have a 1500 watt electric space heater. It costs 19.5 cents per hour to operate. Roughly, I get 3.4 times more heat per dollar using a gas space heater vs. an electric one.

 

[hurk27]

Just for math fun

I have a 9000 BTU (2637 watt equivalent) gas space heater. It costs about 10 cents per hour to operate.

I have a 1500 watt electric space heater. It costs 19.5 cents per hour to operate. Roughly, I get 3.4 times more heat per dollar using a gas space heater vs. an electric one.

And it should always come out that way or close as with electric heating you are converting energy twice first heat to electric then back to heat, because of this there will be losses, of course hydro offers a lower cost solution but heat produce directly via a fuel will always produce more heat because of the single transfer theory, ever notice older electric dryers have a longer duration timer? I have seen some with a two hour timer on them, try this test, dry a load of heavy towels in a gas dryer then try it in an electric, see if it doesn't take longer in the electric, then there is the cost, here the cost is over 6 times between the two as our electric here is one of the highest in the US next to com-Ed.

Had a new customer who moved from Florida and had a house built and wired by someone else, they called me to find out why their utility cost was so high, well they made the mistake of having all electric heat installed 43.2kw of heating (3x14.4kw heating elements in 3 forced air furnaces), two large electric water heaters @5800 watts each, it was the first time I have ever seen a home require a 400 amp service around here as most only calculate out to be around 65 amps load with all gas appliances, their bill was over $1,000.00 a month, the electric appliances and heating was removed and all gas was installed, including a gas fired tank-less water heater and their bill is now is around $300.00 a month.

now in another area it can be different as if no NG is available propane can be costly in some areas, so the rule is do your home work, and for us who know which way is more expensive then we should advise our customers when we see a mistake like this about to be made, I do this all the time.

 

[kbsparky]

TAKE a closer look at the nameplate ratings of these appliances.

Many of them in order to boost ratings use 125 Volts (as opposed to 115 or 120 Volts) to make it appear that the devices puts out more heat than it actually does. Reducing the supply voltage to your actual nominal supply will make for less Amps (and consequently much less watts) output....

 

[hurk27]

TAKE a closer look at the nameplate ratings of these appliances.

Many of them in order to boost ratings use 125 Volts (as opposed to 115 or 120 Volts) to make it appear that the devices puts out more heat than it actually does. Reducing the supply voltage to your actual nominal supply will make for less Amps (and consequently much less watts) output....

ever do the math? I did, they would have had to use 140 volts or close to it to even get even close to claiming the 1875 watts they claim:roll: