Improving central heating

[Piwoslaw]

Originally Posted by Barrowman

I have been wondering how I could do it without using a lot of power to produce it. I guess there has to be a sweet spot but exactly what that would be is probably something I would have to do empirically. I might get a few smaller PC fans and arrange them in a row along the bottom rather than a bigger fan with ducting. I can get 4 of the 60mm fans from Amazon at GBP9 and they are 5V 0.1amp each with air flow of 13.8CFM

If I were to invest more into this idea, I would experiment with a squirrel cage fan, but with a looong fan, like this:

This would give an even flow over a longer length.

If you do go with the PC fans, take the largest diameter you can. Take the next largest and mount it diagonally to make it fit. The reason is noise - the smaller the fan, the higher the rpms and the worse the noise.
I had to put a resistor on 1 or 2 of mine to make them acceptable by the family.