Re: A different Idea for a shop:
Yeah Pat,
I could glean quite a lot from Egon's woodworking experiance. [img]/forums/images/icons/smirk.gif[/img] But, I figured out the problem with my rafters....It was my miter saw cuttinum too short!! Actually, I'm using metal ties and when I attach them to the bander board (ledger brd) I've not been compensating enough for them.
When nailed flat they are about 3/32 tck but when their middle is nailed to bander brd and wings wrapped around end of 2x6, they tend to hold the end out just a bit more than expected. But I' m now shaving a little off the top end of rafter which results in a more perfect fit of birds mouth to ridge cut.
With gambrel roof on my barn the sides are just over 12ft, I have a 10x51 porch roof growing out the west side of it. [img]/forums/images/icons/smile.gif[/img]
I used 9ft 6x6 posts and bolted on 2x8 header (Boxed) and now installing the 2x6x12ft rafters 24ft OC. It'll have a good "chimney" space at the wall/porch roof junction and for short term I'll put up screen material to keep out critters, and later on, put in the double rafter, ridged foam and stuff.
Even now, when I'm attaching the porch rafters to the side wall, I can feel a really good breeze flowing out spaces between the rafters across the loft floor.
Continuing on underside of porch roof deck and under barn roof deck, I'll install foil-backed ridged foam to inside of the low roof rafters forming chimney up over the 8ft knee wall (storage area) into the attic space above the loft room. As you point out, Pat, the thermal efficiency of heated air moving through, coupled with venturi effect drawing on these chimneys per ridge vent should create excellent air exchange/hr.
Later on when we screen in the porch (wife wants it), I'd like to be able to "winterize" it. Also might could vent the wood shop air to these chimneys as long as I don't pull in small dust particles which would eventually build up and cause fire hazard.
Wonder if the thermal draft in these chimneys might be ample to drive a wind turbine generator? [img]/forums/images/icons/cool.gif[/img]
Have a blessed day, Pat.
Re: A different Idea for a shop:
RoyPat, Another consideration as regards the foil backed rigid foam besides installing it with the foil towards the roof is that it accumulates dust and over time you can lose considerable performance. If you get enough wind maybe it will self clean or every couple years you can spray some kittens with "End Dust" and turn them loose up there.
As regards the wind driven turbine(s)... Yup, you could probably build some that would work within your parameters but the useful output might be a bit lower than you might hope for. You might be able to charge a battery enough to light up a some low power LED night lights or something like that. Maybe you could settle for a wind chime in the venturi or a bell with its clapper attached to a "sail" so above a threshold speed it would ring. That would announce when the system was working.
I agree about preventing unfiltered air from a woodworking operation getting sucked up into the "venturi." Except for that, I'd think you could harness the available moving air column to suck the hot air off the ceiling level of your shop. Just install some grills in the ceiling and use ducts to tap into the cavities with the air currents. Think Bernoulli!
[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]
Re: A different Idea for a shop:
Oooooooooh, man, now let's see.....The Bernoulli principle...doesn't that mean you can tell how fast ye ol' "Bern" will travel if "oulli" the sluice gate were in the open position, the flow is steady and the angle is straight? I really didn't have a clue, Pat, but I looked it up and learned something new! [img]/forums/images/icons/smile.gif[/img] (http://www.imnoeng.com/Flow/bernoulli.htm)
Concerning your idea of "installing some grills in the ceiling and use ducs to tap into the cavities..." I'm kinda reluctant to try that application. I'm not sure if I have the desire to cook my burgers upside down on the ceiling and I never could keep my ducs lined up so think I best just stick to installin vents through the shop ceiling into the attic space. That way if a duc...or for that matter a "end-dusted Kat" trys to go that way I'll be more likely to track um' if their viscous effects are more then the dust already in there.
All seriuosness aside, Pat, I may try something different in the wood shop. My I-joists are on 16"OC and wanting to have flush-mounted light fixtures, I'll need to use 1 or 2 bulb light fixtures (something that fits between the joists) perhaps a series of 4ft units. I may install a "U" shaped panel wedged between the joists to serve as a ceiling cover, a sound deadener, and a means by which to effect a funnel for air moving to and through ceiling vents. The vents could be attached to the air exchanger/filter to help maintain low airborne dust particles. Not sure how or if this would work, or what material to use but was just sorta thinking outload. If smooth like sheet metal it might bounce noise rather then absorb, and a textured surface might catch and hold too much particulate matter. At any rate I'm pressing in to the discharge of expanding my barn roof perimeter, one rafter at a time.. As they say "onward" and "upward"..............
Have a blessed OK country day, Pat [img]/forums/images/icons/smile.gif[/img]
Re: A different Idea for a shop:
RoyPat, Don't think me finicky but I think the plural of duc is dux!!!
My shop ceiling is 10 ft. I have lights suspended just a bit below the ceiling. I also have A/C ducts suspended below the ceiling and aspire to have dust collection ducts suspended below the ceiling. The tops of the A/C ducts are about 7 inches below the ceiling to leave room for the dust ducts.
The lights have 8 ft monopole fluoprescent tubes (small diameter new fangled size) in three rows of three in a row. During the day I rarely use them but if you turn them all on it lights the place up like an operating theater... quite intense.
[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]
Re: A different Idea for a shop:
Pat wrote: </font><blockquote><font class="small">In reply to:</font><hr />
If you get enough wind maybe it will self clean or every couple years you can spray some kittens with "End Dust" and turn them loose up there.
[/ QUOTE ]
ManOMan, I laughed so hard I pooted.
Dick
Re: A different Idea for a shop:
Hey Pat. Well I L B, M R dux!! And I learned a long time ago to watch um fly over with my mouth shut....especially geese!!
My shop ceiling is 10-9 (plus the 14" I-joist space to install light fixtures). I'll be using 8 footers (also with F8 bulbs) they seem to be more energy effecient then two 4 footers.
My goal is to end with a flush mount for anything I put in/on the ceiling, and not create dust collectors like I presently have in my garage, suspended light fixtures with no lenses so my sawdust (fine sanding dust) gets very heavy at times on the bulbs and the fixture tops. I'm not that picky to keep them dust free, but I'ld like to start the new shop with a more effective dust cleaning venture. The 14" joist space should be plenty room for lights, lites, ducts, ducs or dux (or the "Louziana" style with Doux).
A couple articles I've read say the energy saver-economy lights are not really economical, as they use more energy while producing less light. Like back in the 80's when Mfgrs' "detuned" the carburated engines to meet new EPA standards. But depending where I place saws, jointer, and other equipment and benches, I plan to use 6 rows of two fixtures in 17x26 shop.
But the barn/shop/garage is coming right along. I finished raftering the 10x51 porch and will be decking it in the next few days whenever the rain stops. It's slow going when all I have is late evenings and partial weekends, but I'll get there. If you like to play in the dirt, swing a hammer, make sawdust and sweat, come on out !!! Got plenty camper space!! [img]/forums/images/icons/smile.gif[/img]
Have a blessed OK day , Pat