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Subject: Market Farming
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- From: "David Inglis" <mhcsa AT bcn.net>
- To: <market-farming AT lists.ibiblio.org>
- Subject: RE: [Market-farming] Re: Greenhouse- milk jugs
- Date: Fri, 7 Feb 2003 22:30:35 -0500
Title: Message
I was told that in most parts of the U.S. there is
'theoretically' enough btu's coming in over the year to keep a Greenhouse at 65F
year round. Most of us are farming in a less than theoretical world
though.
People will tell you that it is difficult, and
expensive' to provide enough thermal mass within the structure to eliminate the
need for heat in a warm house but that need not be the only goal that would be
worthwhile.
Under bench storage of thermal mass makes great
use of unused space but if you are doing in ground growing of crops it wont
work.
Hung milk jugs or soda bottles can contribute
significantly to protecting crops in a cool house especially when combined with
other measures such as row covers, sidewall or in ground insulation; the effect
of combining each of these heat savers is more than accumulative, it is
synergistic. As you say, milk jugs hung up will not provide enough warmth
to eliminate the need for night heat but they will act as a thermal flywheel
reducing the extremes of heat during the day and cold at night as well as slow
the speed the temperature changes at.
On a daily basis the bottles are a more effective
flywheel because they have a high surface area to volume ratio and therefore
heat up faster and give up that heat faster. I think of it like charging and
discharging a battery. What is the point of having a barrel full of water that
is still warm after a long cold night? It is like having a nearly full
irrigation pond at the break of a drought. 'The ideal is a just emptied pond
when the first rains fall' [ P.A.Yeoman's ]
Barrels are more effective at carrying one season into
the next.
Steve Moore in PA has done more than most in this area
and I know he got a grant for temp. sensing equipment but I don't think the data
is in yet.
I have a question for
anyone with experience growing in unheated tunnels
[Alison?]:
Which do you think is
more damaging to 'winter' crops in unheated tunnels, temperature extremes or
rapid temp. changes?
David
Inglis
Mahaiwe Harvest
C.S.A.
Marie,
I'm not sure what you will be growing in it, and what temps are needed.
For passive solar, I use 50 gallon plastic barrels on their sides, filled with water under my benches for about 120' total. The 'free barrel source' ended before I got enough to complete the whole thing. It does not provide enough release heat for that greenhouse, which is 75' x 20', and has solid, insulated 4' walls, and inflated bubble. I keep potted tender herbs, fig trees, scented geraniums, etc. in it. What the barrels do offer- is to help with the night temps thus save me fuel $$, and since this heat is radiating up, I have found it great for propagating late summer cuttings. Also, the barrel's did save plants when the heat went out one winter. Lost a bit of foliage, but not the roots.
I'd Google it. Good Luck-
Patricia
theherbgarden.biz
Today, it is 16 degrees and sunny here in north central Missouri. Our
new hoop house is all toasty warm. I wonder if I filled milk jugs with
water and stacked them up somewhere in the hoop house, would they warm
enough during the day to keep the house warm at night? Does anyone have
any data on something like this?
Marie in Missouri
-
[Market-farming] Re: Greenhouse- milk jugs,
PATRICIASHERBS, 02/07/2003
-
RE: [Market-farming] Re: Greenhouse- milk jugs,
David Inglis, 02/07/2003
-
RE: [Market-farming] Re: Greenhouse- milk jugs,
bob, 02/07/2003
-
RE: [Market-farming] Re: Greenhouse- milk jugs,
David Inglis, 02/08/2003
- RE: [Market-farming] Re: Greenhouse- milk jugs, bob, 02/08/2003
-
RE: [Market-farming] Re: Greenhouse- milk jugs,
Leigh Hauter, 02/08/2003
-
RE: [Market-farming] Re: Greenhouse- milk jugs,
jay gee, 02/08/2003
-
RE: [Market-farming] Re: Greenhouse- milk jugs,
Dave Lilligren, 02/08/2003
- Re: [Market-farming] Re: Greenhouse- milk jugs, Willie McKemie, 02/08/2003
- Re: [Market-farming] Re: Greenhouse- milk jugs, Victor Jackowsky, 02/08/2003
-
[Market-farming] burning firewood,
Errol Castens, 02/09/2003
- Re: [Market-farming] burning firewood, jay gee, 02/10/2003
-
RE: [Market-farming] Re: Greenhouse- milk jugs,
Dave Lilligren, 02/08/2003
-
RE: [Market-farming] Re: Greenhouse- milk jugs,
jay gee, 02/08/2003
-
RE: [Market-farming] Re: Greenhouse- milk jugs,
David Inglis, 02/08/2003
-
RE: [Market-farming] Re: Greenhouse- milk jugs,
bob, 02/07/2003
-
RE: [Market-farming] Re: Greenhouse- milk jugs,
David Inglis, 02/07/2003
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