re: solar barn -- "first sun"
26 feb 2004
david delaney wrote:
>>i put a description, comments, and some early performance numbers at:
nice work :-)
>what was the thickness, composition, source, and
>method of attachment and hinging, of the flapper valves?
i've used dry cleaner bags with duct tape over the upper edge and
staples through the duct tape. hinging them higher than the upper edge
of the vent holes would reduce the bouyant air force and temperature
required to hold them open, and making them one continuous flap vs
individual flaps would tend to reduce air leaks when they are closed.
you might manually hold them open for a few minutes a few times
during the day to see if that reduces the outlet air temp, compared to
i used these valves on a large sunspace with flexible polyethylene film
glazing, and had a problem with them opening and closing on windy nights
as the wind flexed the glazing, which pressurized and unpressurized the
sunspace and pumped air into and out of the valves...