TEC waterchiller

[Xeon th MG Pony]

I will undervolt. I could get another powersupply if i wanted to go past 300W of input power. But I think thats wasteful enough as it is. And as you can see from my post about temperature control I dont plant to get water temps down much below ambient. Atleast not until I feel like undertaking a big insulation/isolation project.

I am not sure what you are trying to calculate there Hollo. If you compare cooling power with max 70W you need to stay at 0 deg temp delta.
And when temp is constant cooling power is linear to voltage in the working range of the peltier element.
So a better calculation would be
Qc@6V (6/15)*70 = 28W (280W for all 10)
P@15V = 121W
I@6V = (121W/15V)*(6V/15V) = 3.2
Pi@6V = 3.2*6 = 19.2W
COP = 28W/19.2W = 1.458

Althoug I feel this is wrong too. I will look up correct numbers later today.
COP should be higher.
With 300W of input power a working point COP could be as low as 0.66.
And peltiers should be able to reach between 20-30 degrees delta at this temperature. That would load my HS with 500W, 50W each.

If voltage goes down current must go up!

What you really should be doing is wiring them in series so they can take 140V, then rectify AC to DC with a filter then feed it to the pelts through a veriac. This will keep current within sane levels and still provide full power.

If you wanted to get really fancy you could use a chopper circuite to regulate current and inject a PWM to the chopper reset circuit to control over all cooling capacity.