electrical watt vs heat watt?

[ejonesss]

i was wondering if an electrical watt is the same as a heat watt.

if i have a 10000 btu 110 window air conditioner and i convert 10000 btu to watts i get 2900 watts.

i convert 3000 to round it even watts to amps using ohm's law at http://www.the12volt.com/ohm/ohmslawcalculators.asp 3000 watts and 110 volts i get 27 amps

that is more than what the outlet can handle and it would trip the breaker or blow fuses.

most electric heaters are rated at 1500 watts or 5000 btu

apply the ohm's law i get 13 amp just under the limit of most outlets at 15 amp

yet a youtube video http://www.youtube.com/watch?v=9jt1m0ulEiM shows one of them oil filled heaters only drawing 4 amps

does this mean that you can not directly convert heat watts to electrical watts?

update: i could not think of the word but is there some counter intuitiveness going on between heat and electrical watts because i heard somewhere that the watt is a universal number?

is this mean i can safely put 2 or even 3 1500 watt heaters on the same line?

 

[dnmun]

duplex outlets in the wall are on a 20A circuit. only lighting circuits can be 15A.

you can assume the btu rating is fudged a little imo. i don't even know what my window AC is rated.

 

[friendly1uk]

It's free energy, I tell you. Every watt of electrical energy can move about 3 watts of heat energy. That's why we are using more peltiers these days, they need to get the old free tech off the shelfs before people recognise it for what it is.

 

[gogo]

Its monkey business. Find the SEER number for your air condoner and divide it into your BTU rating. Does that number look more realistic as a wattage?

I seem to remember you have to dig deep to find the monkey.

Example: I have a '5000 BTU' rated window unit that is listed as 515W, 5.2A (@115V) on its sticker.

 

[liveforphysics]

A watt is a unit for power.

A watt is a watt no matter the form.

An AC unit can only transfer heat energy from one side to the other, it can transfer substantially more energy than it consumes doing the work of the transfer (thank goodness).

 

[Modbikemax]

Air conditioners and Peltier devices are heat pumps. The move heat from one side to the other just like pumping water and therefore have a multiplying affect but no extra energy(power) is created. The heat is ambient heat in the atmosphere simply moved from outside the house to inside the house in the case of heating and from inside the house to outside in the case of cooling. Air conditioners are more efficient at heating because the waste heat from the compressor motor is also pumped into the house. In cooling the waste heat must be pumped out and is lost. Typically an air conditioner can pump 3 to 5 times the heat energy for every unit of electrical energy used to drive the pump.

Other heaters like the oil filled electric heater will give 1000 watts of heat for 1000watts of electric power, there is no multiplying affect.
According to well understood laws of physics energy cannot be created or destroyed only converted from one form to another. For example the heat from a wood fire is solar energy stored by the tree in as carbon in its wood.
There are no free rides, so called free energy is promoted by idiots who flunked out on year 7 physics.

 

[dogman dan]

To find out what the real world draw of your house appliances is, get an AC wall meter such as a killawatt.

It will tell you which items are a bitch for your electric bill, and which are not. I found my old freezer was not as big a drain as the guys that sell new freezers would like you to think. The fridge is a bit of a hog, but only because I have my nose in it with the door open so much. The phone charger I never unplug, it makes so little difference to do it. 10 years ago, a phone charger was hot all the time, now it's cool.

It's nice to know in summer what that window AC costs. 70 F is x per day, 75F is y per day. I found running one room cooler was quite worth it, vs turning down the cooling to the whole house. House gets set to 80F, then we chill the room we are actually using cooler.