For the pioneers:

https://r.tapatalk.com/shareLink?share_fid=15442&share_tid=307487&url=https%3A%2F%2Fwww.4x4community.co.za%2Fforum%2Fshowthread.php%3Ft%3D307487&share_type=t

I love how the thread descends into an argument halfway down. Problem is... that negative guy is right. There really is no increase in heating effiency, other than not having to pass it through the battery/inverter loop. The only way to operate "over unity" is a heat pump. Everything else are just ways to flatten a mountain but ending up with the same amount of dirt in a flatter heap :-)

Something I've considered in the past... how about a boost converter driving a normal 230V element? You could even turn the boost converter into an MPPT so it essentially does impedance matching. Then you can use one of those voltex dual elements (no need to make new plates or cut holes). Must say I am a bit horrified at the idea of drilling a hole and bolting it down from both sides. If I'm drilling a hole, I'd get a professional to tap a thread into it.

Edited November 30, 20187 yr by plonkster

On 2018/11/30 at 9:40 AM, plonkster said:

I love how the thread descends into an argument halfway down. Problem is... that negative guy is right. There really is no increase in heating effiency, other than not having to pass it through the battery/inverter loop. The only way to operate "over unity" is a heat pump. Everything else are just ways to flatten a mountain but ending up with the same amount of dirt in a flatter heap 🙂

Something I've considered in the past... how about a boost converter driving a normal 230V element? You could even turn the boost converter into an MPPT so it essentially does impedance matching. Then you can use one of those voltex dual elements (no need to make new plates or cut holes). Must say I am a bit horrified at the idea of drilling a hole and bolting it down from both sides. If I'm drilling a hole, I'd get a professional to tap a thread into it.

There may be no increase in heating efficiency but I can see, on our energy graphs, that the PTC element use much less energy once it has reached target temperature (60 deg in my case) and it will keep it there for a few hours. My normal element used to run at "full throttle", but with some spikes, i.e. spike up to 2KW every few minutes. The PTC element doesn't go above a few hundred watts during that period.