I've read debates about whether it's helpful to turn the heater off from cold start and leave it off until the engine develops good temperature.
Conclusion was it's not necessary to turn heater temp control off; as long as the blower is off not much heat exchanging is going on. It is, however, a good idea to not blast the blower until the engine is warm; blasting it right off the bat will cause a delay in the engine reaching operating temperature....
Have you ever noticed the effect of cold (that nasty 4-letter word!) on time?
...the colder it is, the slower your watch / clock / "our"glass? will run while waiting for BTUs to show up!
Well , sure if Randy's fan is 189 watts that's 13 amps.
Thats quite some current , must blow a gale in there.
It didn't move very much air until I cleaned the leaves out of it. Wonder if it still draws 13 amps? It's got a 30A fuse on that circuit, and the service manual says it's 200w, 250 cfm.
That web site theclencher pointed is just a hp/watts conversion at 85% efficiency. I thought alternators were a lot worse than that, but I think part of that is the fan load... they have to size them for worse-case idle.