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Cathar · 03-18-2005, 06:52 AM

Marci, been plugging through the calculations with a flow calculator and the shroud angle.

10-15 degrees shroud angle from the vertical is optimal for the 16x16 -> 12x12cm shroud, with a pressure drop of 1.9Pa given a 50CFM air-flow, for which 35-50CFM is about the sorts of air-flows we're targetting with the low-noise optimised design.

A 30 degree shroud angle (4cm shroud depth), yields just a 2.0 Pa pressure drop.

A 45 degree shroud angle (2cm shroud depth), yields a 2.1 Pa Pressure drop

Given that the sorts of low-noise fans we're talking about are generating 10Pa air pressures at the sorts of air-flow rates we're talking about, then the variation here is trivial at best. We'd only be talking about impacting air-flow rates by 1% by converting the shroud into a very convenient and compact 4cm depth device (fan mounted on outside), and by 2% from "optimal" if the shroud was an even more compact 2cm depth (fan on outside).

In fact, even moving to a super-compact 1cm depth yields just a 3% loss of air-flow from the "optimal" depth.

I would however suggest that 4cm (30 degree angle from vertical) would be a very nice shroud depth for both the blow and suck fan orientations, and still make for a very compact design.

I feel somewhat responsible that you had that monstrosity of a shroud made up based upon my recommendations. Had I known that you were going to do so, I would have munched the math sooner to realise what the impact would be with shallower (and hence more compact and user-friendly) shroud sizes.

I also had not realised that you were the manufacturer for the Thermochill radiators. Am happy to engage someone who is serious about seeing these things made.

As for your market, I would say that it would extend to pretty much any nation with a healthy economy outside of the USA (i.e. including Australia and New Zealand, as well as parts of SE Asia). Down here we would have plenty of buyers for such a radiator.

Would also suggest that for ease of mounting, since we're considering this as a serious commercial product, that the shroud be avaible for both side, so users could easily attach the radiatior to a 12cm fan mount point in one of many of the modern cases that now support such.

03-18-2005, 06:52 AM	#138
Cathar Thermophile Join Date: Sep 2002 Location: Melbourne, Australia Posts: 2,538	Marci, been plugging through the calculations with a flow calculator and the shroud angle. 10-15 degrees shroud angle from the vertical is optimal for the 16x16 -> 12x12cm shroud, with a pressure drop of 1.9Pa given a 50CFM air-flow, for which 35-50CFM is about the sorts of air-flows we're targetting with the low-noise optimised design. A 30 degree shroud angle (4cm shroud depth), yields just a 2.0 Pa pressure drop. A 45 degree shroud angle (2cm shroud depth), yields a 2.1 Pa Pressure drop Given that the sorts of low-noise fans we're talking about are generating 10Pa air pressures at the sorts of air-flow rates we're talking about, then the variation here is trivial at best. We'd only be talking about impacting air-flow rates by 1% by converting the shroud into a very convenient and compact 4cm depth device (fan mounted on outside), and by 2% from "optimal" if the shroud was an even more compact 2cm depth (fan on outside). In fact, even moving to a super-compact 1cm depth yields just a 3% loss of air-flow from the "optimal" depth. I would however suggest that 4cm (30 degree angle from vertical) would be a very nice shroud depth for both the blow and suck fan orientations, and still make for a very compact design. I feel somewhat responsible that you had that monstrosity of a shroud made up based upon my recommendations. Had I known that you were going to do so, I would have munched the math sooner to realise what the impact would be with shallower (and hence more compact and user-friendly) shroud sizes. I also had not realised that you were the manufacturer for the Thermochill radiators. Am happy to engage someone who is serious about seeing these things made. As for your market, I would say that it would extend to pretty much any nation with a healthy economy outside of the USA (i.e. including Australia and New Zealand, as well as parts of SE Asia). Down here we would have plenty of buyers for such a radiator. Would also suggest that for ease of mounting, since we're considering this as a serious commercial product, that the shroud be avaible for both side, so users could easily attach the radiatior to a 12cm fan mount point in one of many of the modern cases that now support such.