Peltiers and Initial Load Tests

A project log for 1kW Solid State Peltier Heat Pump

Primary/secondary water loops & 12 peltier units with a 0-30°C set-point.

david-scholtenDavid Scholten 02/14/2022 at 06:330 Comments

So I've received a bunch of Peltiers, but the rating labelled is different from the actual performance. I've been flim-flammed.

I also received fans - That's always nice:

(The 12x fake peltiers are just sandwiched in between the heat blocks)

And a triplet of power supplies! One for loop 1, loop 2 and then the fans:

Now, to neaten things up I've made some ASA printed peltier spacers that have been superglued on to hold them in position as they slip around on thermal pads/thermal grease:

I've also made some spacers for the giant fans:

The whole idea is that the "stack" of components can be lifted vertically upwards, but nothing can move laterally and ruin it. It's like a heat block sandwich.

In the end I'm aiming for 4x150-200W peltiers in the sandwich.

Now! Thermal issues! I'm currently cooling with only 60-120W, but I can't get the hot side heat away and am therefore only achieving up to a 4 degree drop from ambient after tuning the input power.

There are many issues that need to be fixed (of which most will go away simply by completing the planned project):

1. The current thermal pads are garbage compared with thermal grease - I'm changing it out for grease now that I have the spacers. This is especially important now that I want only 4 peltier units instead of 12 lower power ones.

2. Heat blocks don't conduct heat from top-to bottom well without water in them! :)

3. That water likely also needs to move, so statically filling it up may not work.

4. The cooling thermal losses from the environment heating the pipes is immense and kind of comical. The air around the piping just feels nice. I'm aiming to overcome this with pure power in the future, but I can always start wrapping things in insulation... These PC copper pipe adapters are designed to bleed of heat with hot water from graphics cards, not stop the cold from escaping...