Air must come into the building to replace the heated air that is exhausted. Is there evidence for the existence of an input opening adequate to achieve this requirement? Are all the doors and windows closed?
Dave -----Original Message----- From: Daniel Rocha <danieldi...@gmail.com> To: John Milstone <vortex-l@eskimo.com> Sent: Sat, May 21, 2016 3:29 pm Subject: Re: [Vo]:1 MW of heat in a 6,500 sq. ft. facility without industrial ventilation would be fatal That's a surprisingly small volume. The machine has one of its smaller dimensions 3 meters. So, even 1.5m/s per second at one end would cool the device. 2016-05-21 15:51 GMT-03:00 Alan Fletcher <a...@well.com>: Back-of-the-envelope calculation I'm going to look at a column of air of volume V -- with area A ... and a height H sufficient to hold 1-second's worth of 1MW of heat. This has to be vented in 1 second. 1MW is 1000 kJ /second. Q = 1000 kJ in one second Specific heat of air at 100C is 1 kJ / (kg K) Density of air at 100C is r = 1kg/m^3 http://www.engineeringtoolbox.com/air-properties-d_156.html Ambient air is 20C, heated air is 100C dK = 80 Q = S * dK * M Mass = 1kg * r * V = r * V Q = S * dK * r * V Solve for V : V = Q / ( S * dK * r ) = 1000 / ( 1. * 80 * 1.) = 12.5 m^3 per SECOND = 750 m^3 per MINUTE = 26,486 CFM (Cubic Feet per Minute) That's a teeny tiny little fan! http://www.industrialfansdirect.com/wall-ventilation.html?&gclid=CIb8x7zb68wCFQEJaQodk4AMnQ From: "Alan Fletcher" <a...@well.com> To: "vortex-l" <vortex-l@eskimo.com> Sent: Saturday, May 21, 2016 10:37:55 AM Subject: Re: [Vo]:1 MW of heat in a 6,500 sq. ft. facility without industrial ventilation would be fatal This chimney sizing link doesn't really apply --- it's for natural draft up a chimney of a given height and diameter -- WITHOUT a fan. (The longer the chimney the higher velocity of the draft, so a given diameter can exhaust more heat. They recommend "The velocity of air and flue gas in a smaller furnace should not exceed 2 m/s. " -- so I presume that the charts are based on this, and not the maximum 10m/s.). I haven't put a ruler on the aerial photos of the vents on the roof ... but it looks like they could easily be 22 inches. Since a 22-inch vent WITHOUT a fan at a velocity of 2 m/s can handle 1MW, it seems likely that a vent WITH a fan could also do so. There's probably a vent/fan sizing chart somewhere, but this isn't it. From: "Jed Rothwell" <jedrothw...@gmail.com> To: "vortex-l" <vortex-l@eskimo.com> Sent: Saturday, May 21, 2016 9:16:31 AM As I said, 1 MW in this space would be like running 16 space heating furnaces continuously without thermostats. To remove that much heat, you need a 22" vent and a large fan. An expert from I.H. would have to confirm this ventilation equipment is installed and working to confirm the claim. 1 MW of heat release calls for at least at 22" vent: http://www.engineeringtoolbox.com/chimney-sizing-d_175.html -- Daniel Rocha - RJ danieldi...@gmail.com
