How much energy to heat a room, and heat pump efficiency?


by ProtoBob
Tags: efficiency, energy, heat, pump, room
ProtoBob
ProtoBob is offline
#1
Dec15-08, 06:59 PM
P: 6
O.K. this is maybe a large question.....

I am trying to find out how much energy it would take to do the work of a heat pump compressor that would be required to heat a.... lets say 10 ft. x 10 ft. room of a typical house.

I know there are a lot of variable here.....

What I am trying to discern from this, is, if there were an alternate method to drive a heat pump compressor motor, how much energy would be required to do so....

Any thoughts?
Phys.Org News Partner Physics news on Phys.org
Physicists design quantum switches which can be activated by single photons
'Dressed' laser aimed at clouds may be key to inducing rain, lightning
Higher-order nonlinear optical processes observed using the SACLA X-ray free-electron laser
russ_watters
russ_watters is offline
#2
Dec15-08, 08:03 PM
Mentor
P: 22,001
You're not looking for energy, you are looking for power. This is very dependent on things like insulation and climate. A good starting guess of required heating for a relatively cool climate (say, the northeastern United States) would be 10 W/sq ft. A decent heat pump has a COP of 2.5 when it is cold outside, so that gives an input power of 4 W/sq ft.
ProtoBob
ProtoBob is offline
#3
Dec15-08, 08:28 PM
P: 6
If I am understanding correctly, thats 10 watts per sq. ft. so a 10 x 10 room would be
100 sq. ft. requiring 100 * 10 watts, or 1000 watts to maintain a "typical" temperature.

Could this also be stated as 1000 watts per hour or 1kwh to maintain room temperature?

would this also be equivalent to 3413 btu per hour?

Thanks! :)

russ_watters
russ_watters is offline
#4
Dec15-08, 08:40 PM
Mentor
P: 22,001

How much energy to heat a room, and heat pump efficiency?


Quote Quote by ProtoBob View Post
If I am understanding correctly, thats 10 watts per sq. ft. so a 10 x 10 room would be
100 sq. ft. requiring 100 * 10 watts, or 1000 watts to maintain a "typical" temperature.
Could this also be stated as 1000 watts per hour or 1kwh to maintain room temperature? [/quote] There is no such thing as "watts per hour". There is watts for an hour, which is watt-hours (or 1000 watt-hours = 1 kWh). Watts is already a rate.
would this also be equivalent to 3413 btu per hour?
Yes, though note that people do a kind of short-hand and often interchange "BTU" and "BTUH". BTU is technically the rate (power, like kW) and BTUH is the energy (like kWh).


Register to reply

Related Discussions
Heat and Internal Energy and Heat and Temperature Change: Specific Heat Capacity Advanced Physics Homework 4
Efficiency of heat pump and refrigerator Classical Physics 2
Heat Pump Introductory Physics Homework 6
Do light bulbs or convection heaters heat a room with the highest efficiency? General Physics 13
Heat capacity of a room Introductory Physics Homework 4