I'm not a mathametician or anything, but I'm assuming that you would need to include such variables as number of people, sex and age of people, size of room, current temperature of room, elevation and others. Does a formula exist for this and if not can any good math students make one up?
2006-11-22 18:26:07 · 7 answers · asked by arbolito 3 in Science & Mathematics ➔ Other - Science
100 watts so can you make a formula?
2006-11-22 19:29:30 · update #1
I'm not trying to figure out cooling requirements. This isn't for any practical application. I just want to see what a theoretical formula would look like.
2006-11-22 23:48:29 · update #2
If the room has no losses then the formula would look like this:
Increase in degree C = constant times h n t / V
where
h = the heat produced by 1 person (say 30 Watt)
n = number of persons in room
t = time
V = volume of room
If we take the volume in liters and the time in seconds the constant is 0.77.
One person, one hour in a completely isolated typical room of 18000 liters (no losses) would increase the temperature by 4.5 degrees Centigrade. In reality the heat is lossed via the walls and windows.
2006-11-23 02:10:25 · answer #1 · answered by cordefr 7 · 0⤊ 0⤋
No equation, but there are a combination of expressions that can help you estimate it. Key assumptions will be:
1. each person contributes the heat equivalent of a 100 watt bulb
2. Size/volume of the room
3. Flow rate and temperature of air moving into and out of the room
The temperature of the room will be governed by:
Amount of heat leaving or entering the room with the air + total amount of heat contributed by the people (approx 100W/person X number of people) X a factor for how well the heat is transferred from the people to the room's air (heat transfer coefficient).
2006-11-23 03:12:58 · answer #2 · answered by Frank M 2 · 0⤊ 0⤋
On average, a person gives off about 100 watts of heat.
That would be good enough for an estimate.
But, you would have to take into account air pressure, humidity, and size of the room.
2006-11-22 19:20:42 · answer #3 · answered by tj70555 2 · 0⤊ 0⤋
It would not be an accurate formula as are the other means of obtaining the cooling requirements. You will have to a determine
it based on an average person. Perhaps the industry has a standard for this.
2006-11-22 21:12:36 · answer #4 · answered by Anonymous · 0⤊ 0⤋
A 100W seems a bit over the top.
In France, at the "Musee des poids et mesures", where the reference "meter" is kept is a small room, there is a 30W heater to maintain the room at steady 20 deg C.
When a person enters, the heater is swithced off.
Hence I would think that 30W is about what a human generates as heat.
But don't quote me on this!
So, if you had a room with 10 people, they generate 300Watts.
2006-11-22 19:56:54 · answer #5 · answered by just "JR" 7 · 0⤊ 0⤋
Both responders are basically correct. A hundred watts is a good estimate for people that are sitting quietly; if they are exercising in some way, the heating can increase substantially.
2006-11-22 19:23:35 · answer #6 · answered by Anonymous · 0⤊ 0⤋
There are too many variables involved in this to make a realistic equation for it.
2006-11-22 19:05:29 · answer #7 · answered by Jim Burnell 6 · 0⤊ 0⤋