The beauty of buying a quality fanless chassis is that it's reusable. Our reader Bogdan owns a 1st generation HDPLEX H3 and went from a i3-3225 (from 2012) to a substantially more powerful i5-7500 in no time.
His biggest challenge was finding a motherboard with a CPU socket and layout similar to the previous Gigabyte Z77N-WIFI, and the Thin mini-ITX
ASUS Q170T fits the bill. Playing 4K content, the Kaby Lake i5 idles at only 39°C.