I am curious about how the actual flow rate was measured. Typically, a door opening is utilized as an instrumented flow path. At the door, one could measure by the pressure drop through a calibrated venturi, but in that case there would be a pressure drop and not only would that cut the actual flow rate of the hood, but there would be some house leakage not measured. Alternatively, if there were also a fan in the path keeping the house pressure at zero to the outside, while also measuring the flow through the fan (by whatever means), then the flow rate measured should be the static value for the entire hood system. Of course, without the test fan providing zero differential, the actual flow will be less depending on where the MUA is sourced. No magic is involved. kas Correction: In an early message above, I asserted: "A fan at the hood can more easily overcome flow resistance between the hood and the outdoors, but normally this resistance is small, a few tenths of an inch w.g., so attic and roof mount fans work fine when properly sized." I now doubt that it matters much whether the restriction is before or after the fan, as most fans have fan curves that are based on total pressure drop around the path and do not differentiate between pushing and pulling. Differences could result from turbulence interacting with structures on one side or the other of the fan, and in such cases the actual flow might differ slightly for the same fan. I don't know how VAH squirrel-cage blowers might behave in this respect.

Am so excited to have drupes on the new Edgeworthia papyrifera that I got this spring. If I can catch them at the right stage of ripe and then get them to germinate ~a year from now, it will probably only be another decade before flowering. So why am I so excited? I don't know but have decided to just enjoy the moment.

They are supposed to be open tomorrow at their old retail location, but if you plan to go, call first because of the low temperatures (919) 854-9892. On Wednesday they begin the final move of their retail operation 1/2 mile down Campbell Rd to the current wholesale location. There are many, many flats of older pansies and violas left for free.

I'm growing tomatoes bred in my own garden (big yellow round all-purpose PL indeterminate cherries), Roma VF, Cal Ace^, New Yorker V, Early Cascade, Amana Orange, Carolina Yellow, Cherokee Purple, Cherokee Lime^, Brandywine Pink, at least one volunteer, Jubilee^, Super Marmande, Marmande, and Sunray^. ^: These are those I haven't grown before this year. The tomatoes I'm breeding are two different projects stemming from a cross-pollinated Medovaya Kaplya plant. The F1 had red ovate fruit. I have two separate main lines. One is a lot more vigorous than the other, but they taste different. Although the F1 did taste like Medovaya Kaplya, they have a more complex, more savory, all-purpose taste, now, and are not as sweet as Medovaya Kaplya. They are the same honey yellow color, though.