Electric Radiant Heaters

electric radiant heaters

electric radiant heaters
WarmlyYours Welcomes Kathryn Scott to Marketing Team
WarmlyYours, makers of energy-efficient radiant electric heating solutions for any flooring surface and bathroom spas, today announced Kathryn Scott has joined the company as Marketing Director, where she will spearhead the company’s trade and consumer marketing and outreach strategies to grow brand awareness and increase market share.
Does the electricity used by an electrical device eventually turn into heat?

If an electrical device — like a TV, computer, fan, light, stereo, etc. — is plugged in a wall socket and running, does all the power it use eventually turn into heat and warm the room by that amount of energy?

This would exclude devices that specifically vent fluids outside the room like clothes dryers, washing machines, dishwashers, vent fans, etc.

For example, a portable Electric Heater with a fan uses some of the electrical power that it consumes to turn the fan so does that mean that it is less efficient than an electric radiant heater? Or does all the power used to turn the fan eventually become heat?

Or if you had two TV sets that used 350W each, would they heat up a room as much as a 700W heater?

The second law of thermodynamics states “The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium” (quoted from Wikipedia).

My memory from my college days (long, long ago!) of what this means is that when you define a system that includes the electric generator and its power supply, transmission lines, and things that use that electricity (the load), the transformation of the original source of energy to something useful is always less than 100% efficient. The losses are in the form of heat.

The question as asked seems to be looking for something other than the thermodynamic answer, though. You imply a kind of isolated system by specifying a room and excluding devices like a clothes dryer with an outside vent. But a room is not an isolated system. If the appliance is an electric heater, with or without a fan, we can probably safely say that all the electricity consumed by the device is turned into heat. But if the appliance is an incandescent light bulb and the room has windows, some of the energy escapes out the windows as light. Not much of the total energy, because incandescent bulbs aren’t very efficient in the visible spectrum and turn most of the energy used into heat, not light. There’d also be some conversion of photons into heat as light passed through the window.

For all practical purposes, though, a closed well-insulated room would warm up more quickly from the 700W heater than two 350W televisions. The reason for that is the heater runs at a high temperature that causes its heat to transfer fairly efficiently to the air in the room (the room has air, doesn’t it? We’re talking a situation we could measure in the average American home?). If the room were build in a laboratory, insulated incredibly well, and conditions outside the test room were maintained at some constant value, the TV vs. heater result would be more nearly equal, given enough time for the TV’s to warm themselves and then transfer that heat to the room.

An interesting aside here is something I read long ago during the “Space Race.” If a spacecraft in space is mostly living area for human beings (think Apollo capsule) and the temperature inside is maintained at a constant 70 degrees Fahrenheit, the radiant heat escaping from that spacecraft would be the equivalent of a body at 70 degrees (see Black-Body Radiation or Stefan-Boltzmann Law). That’s because no man-made insulation is 100% efficient and the heat inside will eventually make its way outside and be radiated away. But because human beings produce about 440 BTUs per hour when at rest, an Apollo capsule from back then had to worry more about dumping excess heat (from on-board electronics plus the people inside) than heating the capsule in the extreme cold of space. Of course, the Apollo 13 emergency eliminated most of the non-human heat sources inside THAT capsule, but that’s a different story…

Heller 230V Electric Radiant Wall Heater