Originally Posted by pickerdd
I'm curious about the efficiency of the Fan-tastic vents. Do they use a lot of voltage and drain your battery if you use them over night?
Not trying to be flippant, but it depends on:
How good your batteries are and what state of charge they are in when you begin.
What capacity batteries do you have.
How many fans you run,
What setting do you run them on.
Which model fan they are.
What else is running.
And probably several other things I can't think of now.
If you call:
FanTastic Vent - Home Page
They can probably tell you how much current they draw and from that probably get a good idea of how long they can run.
And just an educational side comment:
All the DC appliances run at a nominal 12 volts. The question is" how much energy (watt hours) do they consume". In this case, since power (watts) equals voltage times amperage and energy equals power times time; if you find out how much current (amps) the fan(s) draw, you can then figure out how much energy they will use and compare that to the battery rated capacity. Of course you have to take into account everything else that is drawing current during the night.
You will probably get responses that say "my fan runs all night long no problem." However use cautioning counting on that applying to your situation unless all the variables are exactly identical.