[Greenbuilding] infrared heaters

[Russell, Richard]

Let's be careful to distinguish between "efficiency" and short-term
perceived comfort. If either type of heater is within the building
envelope, then both will be essentially 100% efficient at converting
electrical energy coming in to heat. The infrared, if designed properly,
might be better at distributing that heat within the room evenly,
particularly if the other is a baseboard unit that both radiates heat
away from the wall where it is mounted and heats up air local to it,
resulting in some convective transport to other parts of the room.
Whatever surface faces a radiating source will absorb heat and start to
warm up. Your skin facing the source will feel warmer, so you might
conceivably feel warmer at a lower average room temperature, while
letting other rooms remain at a lower temperature and thus lose less
heat through the building envelope.

On the other hand, if either type of heater is the sole means of
replacing heat lost through the building envelope to maintain some
constant indoor temperature, then both types will use the same amount of
electric power. Arguably the infrared unit could use more if it radiates
a lot of energy straight out the windows.

Dick Russell
-----Original Message-----
From: greenbuilding-bounces at listserv.repp.org
[mailto:greenbuilding-bounces at listserv.repp.org] On Behalf Of Benjamin
Pratt
Sent: Tuesday, April 29, 2008 3:33 PM
Subject: [Greenbuilding] infrared heaters

One of my students was trying to convince me that infrared electric
heaters are much more efficient than typical electric heat. Without
researching it, I'm thinking, how can it be more efficient than 99
percent?

Save me the time of researching it--what do you all think?
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