What is the best/worst ways to do supplemental heat in a greenhouse?
Steve
Strange. I always used sunlight to warm a greenhouse.
It depends on how cold the nights are. I use an electric heater at
night to keep the temperature warm enough to prevent stunting the
plants. As soon as the sun comes up I have to watch the thermometer to
make sure that it doesn't get too hot.
The only time I run the heater is when I have seedlings in the
greenhouse. I do not try to grow stuff during the winter since the
quality of produce is not worth the cost.
--
USA
North Carolina Foothills
USDA Zone 7a
The best is the least inexpensive method, whatever that is for your setup
and area. I have seen setups area in more temperate areas use a closed loop
system w/ a hose coiled under compost. Others; water barrels painted black
for heat sinks, These tricks don't work here in the cool PNW maritime
climate. The C02 could boost plant health, but it would be a waste of time
it your plant are dormant as most are in winter. If you are a commerical
grower then heating is a cost of business and you usually get a bit of heat
from all those 1000w bulbs.
I am building warming benches (bottom heat ) w/ heat cables( ~1$ a foot+
thermostat), but electricity is relatively inexpensive here compared to
fuel. I can put plants on the warm sand and if necessary, enclose them with
bubble wrap, all inside the house. Old christmas lights wrapped around
plants can help, the old 100W bulb is good for a few feet in an open GH, I
would use a blower if you use a propane BBQ grill, definate test by temps at
various feet away from heat source.
here are the commericals setup: http://brae.calpoly.edu/CEAE/greenhouse.html
Use a layer of rocks on the floor to hold heat from the daytime sun.
This isn't rocket science.
Hmmm ...
Do plants need Oxygen as well as CO2?
The root growth for new plants I believe needs Oxygen more than CO2.
If one puts the propane barbecue heater inside the greenhouse this may
be bad for the plants because the heat would use up the Oxygen. If I
went with a propane heater it would be a camper style heater in which
the heater is outside and blows the heat inside the greenhouse OR has an
exhaust vent to the outside. Electric mats under the plants are probably
the best way to go. Electric is also nice for the over head watering
systems.
Electric can be a problem if the greenhouse is not near a power source.
So therefore ... propane.
Enjoy Life ... Dan
--
Garden in Zone 5 South East Michigan.
That being the case then water would be the heat sink of choice because
nothing holds heat better than water. Ideally, the container would be a
thermal conductor, but fish tanks, or other transparent materials would
make it easier for the water to trap the heat.
--
"When you give food to the poor, they call you a saint. When you ask why the poor have no food, they call you a communist."
-Archbishop Helder Camara
http://tinyurl.com/o63ruj
http://countercurrents.org/roberts020709.htm
OK, bad humor. Passive solar applications and man's useage has long been an
interest of mine. There are too many varibles for it to be a reliable
source of heat, perhaps a good supplement, but the other side of the coin
is that heat sinks work in the summer much better, usually to the deterimate
of the plants.
> Hmmm ...
>
> Do plants need Oxygen as well as CO2?
>
> The root growth for new plants I believe needs Oxygen more than CO2.
> If one puts the propane barbecue heater inside the greenhouse this may
> be bad for the plants because the heat would use up the Oxygen.
I don't believe any of these three points are necessarily true.
> If I
> went with a propane heater it would be a camper style heater in which
> the heater is outside and blows the heat inside the greenhouse OR has an
> exhaust vent to the outside. Electric mats under the plants are probably
> the best way to go. Electric is also nice for the over head watering
> systems.
Good to vent the Carbon Monoxide buildup if people work in the area and I
agree bottom heat is better.
>
> Electric can be a problem if the greenhouse is not near a power source.
> So therefore ... propane.
and for emergency situations a charcoal or wood grill would help.
>> Use a layer of rocks on the floor to hold heat from the daytime sun.
>> This isn't rocket science.
>
> That being the case then water would be the heat sink of choice
> because nothing holds heat better than water.
Nothing? Really?
LOL!
The moisture produced will condense on the glass, releasing its heat to the
outside through the glass. Efficiency suffers.
Picky are we? OK, one thing is better at holding heat, ammonia.
--
�When you give food to the poor, they call you a saint. When you ask why the poor have no food, they call you a communist.�
-Archbishop Helder Camara
http://www.jpost.com/servlet/Satellite?cid=1261364551818&pagename=JPost%2FJPArticle%2FShowFull
http://countercurrents.org/roberts020709.htm
>one thing is better at holding heat, ammonia.
I assume we're talking about specific heat?
Is the ammonia allowed a phase change?
Gary Woods AKA K2AHC- PGP key on request, or at home.earthlink.net/~garygarlic
Zone 5/6 in upstate New York, 1420' elevation. NY WO G
> In article <hi2me9$5ua$1...@news.eternal-september.org>,
> "Bob F" <bobn...@gmail.com> wrote:
>
> > Wildbilly wrote:
> >
> > >> Use a layer of rocks on the floor to hold heat from the daytime sun.
> > >> This isn't rocket science.
> > >
> > > That being the case then water would be the heat sink of choice
> > > because nothing holds heat better than water.
> >
> > Nothing? Really?
> >
> > LOL!
>
> Picky are we? OK, one thing is better at holding heat, ammonia.
A search for R-values via
http://en.wikipedia.org/wiki/R-value_(insulation)
Seems related.
Bill who noticed that a wet hand is very much colder than a dry one.
--
Garden in shade zone 5 S Jersey USA
http://www.brasschecktv.com/page/757.html What is Global Dimming??
Less light more shade world wide food implications
>> In article <hi2me9$5ua$1...@news.eternal-september.org>,
>> "Bob F" <bobn...@gmail.com> wrote:
>>
>> > Wildbilly wrote:
>> >
>> > >> Use a layer of rocks on the floor to hold heat from the daytime sun.
>> > >> This isn't rocket science.
>> > >
>> > > That being the case then water would be the heat sink of choice
>> > > because nothing holds heat better than water.
>> >
>> > Nothing? Really?
>> >
>> > LOL!
>>
>> Picky are we? OK, one thing is better at holding heat, ammonia.
>A search for R-values via
>http://en.wikipedia.org/wiki/R-value_(insulation)
>Seems related.
>Bill who noticed that a wet hand is very much colder than a dry one.
and confuses conduction with evaporation.
Sheesh, I'm gonna have to start carrying my roll of taped up dimes
again, when I wander into the garden. I'd say that the group had spring
fever, but I know it isn't spring.
Sure, let the ammonia have a dang phase change. Make it plasma if you
like. Don't be timid now. Where are you going with this? Is there a
planet circling a star in Andromeda, where if one knows where to look,
there is this substance under a rock, that makes water #3? (In specific
heat that is, not like ice #9.)
What leads you to that flange-headed opinion? Uh, if I may ask?
>> On Wed, 06 Jan 2010 18:02:47 -0500, Bill who putters <b2fore...@snip.net>
>> wrote:
>> >In article
>> ><wldbilly-C02C4A...@c-61-68-245-199.per.connect.net.au>,
>> > Wildbilly <wldbilly@without_a.net> wrote:
>>
>> >> In article <hi2me9$5ua$1...@news.eternal-september.org>,
>> >> "Bob F" <bobn...@gmail.com> wrote:
>> >>
>> >> > Wildbilly wrote:
>> >> >
>> >> > >> Use a layer of rocks on the floor to hold heat from the daytime sun.
>> >> > >> This isn't rocket science.
>> >> > >
>> >> > > That being the case then water would be the heat sink of choice
>> >> > > because nothing holds heat better than water.
>> >> >
>> >> > Nothing? Really?
>> >> >
>> >> > LOL!
>> >>
>> >> Picky are we? OK, one thing is better at holding heat, ammonia.
>>
>> >A search for R-values via
>>
>> >http://en.wikipedia.org/wiki/R-value_(insulation)
>>
>> >Seems related.
>>
>> >Bill who noticed that a wet hand is very much colder than a dry one.
>> and confuses conduction with evaporation.
>What leads you to that flange-headed opinion? Uh, if I may ask?
look up evaporation. Look up conduction. Try to learn the difference.
Another hint: R only refers to one.
Presumptuous and derisive, therefore, you must be a poser. Well, good
luck with that, flange-head.