Rator bench testing · 10 runs

Finding the sweetspot

Across all bench data, mean cooling COP is 5.42 at 32 peltiers and 6.16 at 64. The single best operating point we’ve recorded sits near 20% peltier / 40% fan — running the modules gently is how this system likes to live.
32 peltiers
6 runs · 199.9 h logged
5.42
mean COP
361 W
thermal out
106 W
electrical in
peltier duty 0–100% · fan duty 0–100%
64 peltiers
3 runs · 37.7 h logged
6.16
mean COP
450 W
thermal out
153 W
electrical in
peltier duty 0–50% · fan duty 5–100%

COP vs peltier duty

Thermal extraction vs peltier duty

COP vs fan duty

Operating-point map

Supply temperature changes everything

Higher supply means a bigger ΔT against ambient (more passive heat loss bled by the radiator surface) and a hotter peltier hot-side (lower TEC efficiency). Both pull COP and thermal numbers around independently of peltier or fan duty.

Fan-up, power-down — the paradox

Last run (2026-04-25) only. Peltier duty was held at ~30 % while we swept fan duty. The drive is constant-current with the voltage left free, so as the fans cool the hot side the peltier modules' resistance drops, voltage drops with it (P = I·V), and total electrical input falls — even though the fans themselves draw a bit more.

Loop temperatures (run averages)

Per-run detail (click to expand)

Each section embeds the full per-benchmark page with all panels and legend toggles preserved.

2026-03-1932 peltiers41.8 h · supply 28.6 °C · pd 53% · fan 50%
2026-03-2132 peltiers52.5 h · supply 28.6 °C · pd 0% · fan 0% · baseline
2026-03-3132 peltiers48.0 h · supply 37.6 °C · pd 43% · fan 0%
2026-04-0332 peltiers42.3 h · supply 35.4 °C · pd 3% · fan 69%
2026-04-0532 peltiers62.0 h · supply 34.7 °C · pd 41% · fan 72%
2026-04-0832 peltiers4.7 h · supply 34.5 °C · pd 51% · fan 74%
2026-04-1032 peltiers1.2 h · supply 44.5 °C · pd 100% · fan 42%
2026-04-2364 peltiers13.8 h · supply 36.5 °C · pd 36% · fan 68%
2026-04-2464 peltiers9.8 h · supply 46.9 °C · pd 28% · fan 40%
2026-04-2564 peltiers14.1 h · supply 47.0 °C · pd 30% · fan 22%

Per-run breakdown

benchmarkconfighours peltier dutyfan duty supply peak ΔT electricalthermalCOP COP (peltier-attr.)
2026-03-1932p41.853.4%50.1%28.6 °C2.06 °C78 W188 W3.651.06
2026-03-2132p52.50.0%0.0%28.6 °C0.56 °C8 W72 Wbaseline
2026-03-3132p48.043.2%0.0%37.6 °C5.12 °C153 W450 W3.171.55
2026-04-0332p42.33.1%69.5%35.4 °C3.88 °C28 W311 W13.104.37
2026-04-0532p62.040.9%72.0%34.7 °C5.94 °C135 W433 W3.421.92
2026-04-0832p4.750.9%73.9%34.5 °C5.94 °C189 W442 W2.321.45
2026-04-1032p1.2100.0%42.0%44.5 °C4.38 °C196 W532 W2.710.99
2026-04-2364p13.836.4%68.4%36.5 °C4.87 °C212 W374 W2.140.89
2026-04-2464p9.827.5%40.0%46.9 °C5.63 °C120 W563 W15.031.96
2026-04-2564p14.129.6%22.1%47.0 °C4.94 °C120 W446 W3.891.09