I have tried two devices:
- a 150W heater like this one
http://i00.i.aliimg.com/wsphoto/v0/3...ooling-Fan.jpg
- a 300W heater like this
http://i00.i.aliimg.com/wsphoto/v0/5...ble-b-font.jpg
I was very disappointed from the 150W. Noisy, unabble to defog.
The second was better but all the windshield was not defoged.
Finally I open both devices and re-use only their ptc heater. I removed the polen filter and placed the 2 ptc heater here:
This is the best, no noise, all the windshield and front windows defoged.
The 2 ptc heater are connected via a fuse and relay to the 12v battery, that is 14v when driving. The relays can only be energised when the blower is on.
I mesured 700W. This added to the 250-300W constant consumption (ecu, pump, blower, lights...) give 1kW. This is the maximum allowed by the dc-dc converter that provide the 14v.
I can select one (the biggest) or the 2 ptc heater. But 90% trips I use both.
The quicker driving, the colder will be the windshield. The more rain also.
