Electric Cabin Heater for GA Aircraft

[nomorecatering]

Question for any Electrical types Out there.

I was thinking about an electric cabin heater for a light twin, similar size to a Baron, Aerostar, Chieftain to take the place of the tradition Janitrol fuel powered cabin heater.

If you use a new type ceramic heater of say 500w power, I was wondering what current draw it would have and would the aircraft alternators be able to support the load. ..........24v system with 2 x 75 ampre alternators. Note, would design a heater from scratch, not using a house hold heater.

My theory notes say that Ampreage = watts over volts which gives me a current draw of around 20 amps. (500 over 24 = 20 approx).

Do the two alternators give a combined load of 140 amps, therefore 20 amp draw would be minimal.

just wondering what current draw an electric aircon system would use, as well as landing lights, prop de-ice, etc??

any help would be ,uch appreciated.

[L-Band]

The only airplane i have seen with an electric heater is the Cessna 425 and it was installed under the co-pilot footplate.
This unit took around 75 amp when switched on, however on the 425 you have 2x500 amp starter generators.

If you have 2x 75 amp alternators the combined load avialiable would be 140 amps, however alternators are not 100% efficenent, and combined with the odd poor ground and oiled up connection make the output more like 120 amps.

20 amps seems very small, would that be enough to heat a fairly big space?

You also have to be quite quick to turn off the unit in event of a failure of one or both alternators.

Air Con takes about 40 amps, the Landing lights and prop de-ice are intermittantly used item anyway.
The only thing is putting the gear down and the use of flaps as they take the most out of the system.

Hope this gives you some idea.

Cheers