Quote:
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Originally Posted by Les
Kryotherm suggests for a 240x120x12.5mm design:
3.7Pa @ 1m^3/min .
h(conv) ~133w/m^2*c and finning efficiency ~80% with 8 tubes
Edit: Finning efficiency ~ 15% with 1 tube
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Was not so much relying on Kryotherm for the suggestion. Pressure-drop seems too low for 30FPI based on Bill's real-world data.
Extrapolating from BillA's Thermochill 120.2 results offering ~10Pa of air-flow resistance at 1.0m³/min. The Thermochills have 24FPI. Even if we made the radiator single row and half as thick, at best we're still looking at ~5Pa at 24FPI, and surely somewhat higher at 30FPI.
I was thinking of optimising around the
Papst 4412FGL, say at 75m³/hr, or 1.25m³/min, which that fan will push against ~5Pa. If we do some
very rough extrapolation from BillA's data, for a 150x150x16mm core we're talking about ~8Pa of resistance at 1.25m³/min for a 24FPI core of that size, hence my thought to halve the FPI to ~12FPI as well.
Maybe you could run that through the finning efficiency calculator... I suspect upon revising my thoughts that perhaps the best FPI may lie more at 16FPI or so, or at least there is enough of a flow vs pressure vs finning performance tradeoff "plateau" that perhaps anything between 10 to 30FPI is acceptable.
[Edit: Bah - had misread flow charts on Papst datasheets - revised statements]