In my opinion -
Like most things, you get what you pay for. I would suggest they will both work, the question may be more, how long for? how reliable and how efficiently.
In a camper I would suggest definitely get a muffler, in my last van, I could not hear the exhaust. The thing is that on start up, the air fan comes on at high speed and sounds like a jet turbine. Once they get toward the set temp, they slow down and just tick over. Much quieter than an electric fan heater.
So, stop start is not the way to go in my opinion. I ran mine at about 22 deg whilst sitting up before bed, then turned it down to 15 overnight. In 12 hours it used 1.5 litres of diesel and about 12 amps of battery. Leaving it on overnight does several things.
- No stop start turbine noise.[/*]
- Comfortable temperature for sleep.[/*]
- The van/camper is warm to get out of bed and dressed.[/*]
- N.B. No condensation.[/*]
Each time you start it, the glow plug needs to fire up, it draws 10amps when on. It's on for a few minutes until the combustion chamber is hot enough for self ignition.
The other benefit of the Dometic/Erberspacher is that it comes with a digital temperature control, that shows the temp at the control (ambient) and the desired temp.
The Planar comes with a rotary switch which does not give temperature.
Everyone's use is different, each type of install is also probably going to vary. I do know that MYSPOT (username) has a Planar installed in his camper, the vent is in the top, outside corner of his bed, I think he modded the mattress to fit it. PM him, he may send you some pics.