This is a pretty neat product for home owner irrigation. I use a couple of tools that measure volumetric water content like the Acclima product, but one is handheld the other is in the soil. The products I use take the guess work out of when to water. Basically your looking for a percentage of volumetric water content that is just before the point that your turf will start to show drought stress. A lot of people use 15 to 20% volumetric water content as the point at which they water. However this number depends on a lot of factors, type of soil, type of turf, height of cut, health of turf, time of year. I would think in the dry west you would want to volumetric water(VMC) content slightly higher, say 25%. Now is the the time to play around with your system I would set the tolerances low, maybe 15%. Watch to see if your lawn starts to wilt at 15%, if it does then set the tolerance to 20% if your lawn wilts at 20% go to 25%. Good luck this system, used correctly it will save you a lot of water. Here is a link that might be useful: Acclima irrigation.

OK, lets see how it works with a different "rule of thumb" using Galculator (http://galculator.sourceforge.net/), capable of operating in RPN like an HP-15C does and saving me from having to locate mine. Or you can ignore my plug for Galculator and follow using mental arithmetic because the numbers here are all simple. A space of 48 by 27 inches is 9 square feet. Multiplying by 90 cfm/sq.ft yields a desired flow rate of 810 cfm. Duct losses are negligible, but baffle, transition, and MUA losses may be significant. Without more information (particularly a fan curve), we might stick with a nominal fudge-factor of 1.5 for working at some pressure drop on the fan curve. This yields a zero static pressure blower rating of 1215 cfm. 1200 is close enough. If the blower input is designed for a 10-inch duct and the hood output is designed for a 10-inch duct, use a 10-inch duct, even if you have to frame out the studs to accommodate the location. Otherwise, the necessarily abrupt transitions needed to get down to 8 inches and back up to 10 inches within a foot will have some turbulence-caused pressure loss and noise you don't need. kas

floral, the "Ethical Trade Initiative" mentioned in that article contains no actionable information. In fact the article suggests that membership in that organization may actually mean nothing since the members may be cheating. This is an area where a rich foundation could make a difference by doing spot audits on firms and providing ratings, perhaps across a broad spectrum of industry types in India. If a credible third party publishes an expose and highlights firms that behave responsibly, I would steer business that direction. But the way in which you have structured your facts makes two invalid arguments: 1) You are implying that all Indian granite firms exploit children. Maybe most do, but it is not a valid argument to say that because there is evidence of many exploiting children that all exploit children. 2) You are implying that these children will have better lives without these jobs. That is very utopian thinking, and moreover it denies the human being who is affected any input or opinion to your thought process. My guess is that the lives of these children will be even more horrible without these jobs than with them. That's something we in the West turn a blind eye to. We feel moral satisfaction in taking away their jobs, and then we pretend not to see the even greater suffering that we caused by our moral actions. Curing poverty in India is very hard, but I guess the general course of affairs for countries it to accumulate wealth, and to then become more socialist and provide support for the poor. How do you do that *today* in a country where 10% of the population has good jobs or wealth and 90% live in poverty?

opaone: I trust you mean in the sense of capturing effluent headed upward and outward such that it would miss a 27-inch entry aperture boundary by 3 inches. Weifei Zheng: A four-inch high shelf hood really won't have a significant buffer volume (assuming you mean volume below the baffles); the baffle assembly itself might be 1.5 inches thick and will have to be low as possible. The air flow in the volume above the baffles will not have any lingering fumes. But to get the flow at the baffles to be roughly equal across the baffle area, the pressure inside this type of hood has to be low relative to below the baffles, and this pressure loss moves the user up and to the left on the fan curve, reducing volumetric flow rate. Hence the suggestion for zero static pressure rated flow rate to be twice the required operating flow rate. (Also note that I did the calculation for a nominal 24-inch entry aperture (front to back); a 27-inch will require 1/8 more air flow to keep the velocity at 90 ft/min. Maximum stud space ducts of 3.5 x 14 might be advised, along with nearly matching slots in the hood rear.)