Well, today was our first rainy cold overcast day of the year. It really
looks like November today. At 2:30 PM the patio was 50F, the GH was 62F I
turned off the overhead misters so the water doesn't make damp down
everything, making them cold and clammy, and I turned on the little electric
space heater. HA! Talk about useless! So I guess I will go to Grainger, get
the gas valve assembly and fire up the Southern Burner. Drat. Why does this
sort of thing always happen on a holiday weekend when everything's closed?
K Barrett

"alpickrel" wrote in message
oups.com...
You were smart.

My old hoophouse frame is still standing right next to the
greenhouse. It is 15 x 30 (or so). Just the metal frame right now.
It has grapes growing on it. I have had the idea in the back of my
head to cover it with insualtion and black plastic water circulating
tubes and turn it into a giant solar hot water collector/storage unit
of some kind that I can then use at night to pump the heat into the
greenhouse next to it. The heat sink can't be IN the greenhouse
because to be of any real use, whatever goes in there...a pool or
whatever..., it has to be able to get hot enough to be of use long
after the sun gets off it, so plants won't be able to be grown in
there with it. (now I get K Barrett's joke about lying to herself
about her barrel of water.)

I was staring at my electrical subpanel for the greenhouse this
afternoon and wondering what it would take to run a line large enough
to power an electric heater that would make me feel like I was not
lying to myself when I plugged it in.

I still think a good option is to find a way to drag a big warm
blanket over the greenhouse every night.

I also wondered when somebody with the know how will get the bright
idea of turning clear 6 mil greenhouse plastic film into a giant solar
electric collector sheet. I mean I spend all summer trying to REMOVE
light and heat. It would be nice to be doing something useful with
it. There is talk of a spray-on solar panel.

On Nov 9, 8:05 pm, "Pat Brennan" wrote:
When I put up my last greenhouse I needed a new power service. I had the
power company run an extra 200 amps of service and used it for my backup
heating system. The thought that oil now costs the same as that backup
system is as you said scary stuff.

This greenhouse is one third the size of my others. As we started to get
into heating season I was able to empty it and turn it off. As oil
continues to rise I am wondering if between the store (which closes at
the
end of the month) and the little greenhouse if I can close a big
greenhouse.
And if I do not need the greenhouse, I am also wondering how I turn it
into
a solar collector. I think I need to do some reading on heat pump and
transfer systems and swimming pools.

Pat

Is anyone using this method? Sounds intriguing. Knowing the length of the
trench to be effective would be helpful. And what about ducting the hot air
from the greenhouse down through the trench? I can see this method working
on a small hobby greenhouse.


"Ray B" wrote in message
news:6ajZi.1890$cD.932@trndny08...
About the least expensive heating method (it's good for cooling, too) I've
ever heard of was published in the AOS Bulletin in the late '70's or
'80's.

A guy had an extended trench dug 6' into the ground (or some depth
well-below his frost line), and made a long duct of large, unglazed clay
sewer pipe. One end came up through the floor of the greenhouse, and the
other end was enclosed in a structure above ground. The inlet end was
covered with a mesh and filter to prevent all but air from entering.

A thermostatically-controlled fan in the GH drew air through the submerged
pipe, where the natural subsurface temperature was in the low-'60's F year
round, which is certainly plenty warm for nighttime, with solar heating
boosting the daytime temp. In the summer, he would switch to a cooling
thermostat, drawing that same cool air. That's certainly less maintenance
than a swamp cooler!

The article also discussed how the unglazed clay absorbed the condensed
humidity in the summer, and moistened the air in the winter, but I don't
recall details.

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies. Books, Artwork, and lots of Free Info!


"alpickrel" wrote in message
oups.com...
You were smart.

My old hoophouse frame is still standing right next to the
greenhouse. It is 15 x 30 (or so). Just the metal frame right now.
It has grapes growing on it. I have had the idea in the back of my
head to cover it with insualtion and black plastic water circulating
tubes and turn it into a giant solar hot water collector/storage unit
of some kind that I can then use at night to pump the heat into the
greenhouse next to it. The heat sink can't be IN the greenhouse
because to be of any real use, whatever goes in there...a pool or
whatever..., it has to be able to get hot enough to be of use long
after the sun gets off it, so plants won't be able to be grown in
there with it. (now I get K Barrett's joke about lying to herself
about her barrel of water.)

I was staring at my electrical subpanel for the greenhouse this
afternoon and wondering what it would take to run a line large enough
to power an electric heater that would make me feel like I was not
lying to myself when I plugged it in.

I still think a good option is to find a way to drag a big warm
blanket over the greenhouse every night.

I also wondered when somebody with the know how will get the bright
idea of turning clear 6 mil greenhouse plastic film into a giant solar
electric collector sheet. I mean I spend all summer trying to REMOVE
light and heat. It would be nice to be doing something useful with
it. There is talk of a spray-on solar panel.

On Nov 9, 8:05 pm, "Pat Brennan" wrote:
When I put up my last greenhouse I needed a new power service. I had
the
power company run an extra 200 amps of service and used it for my backup
heating system. The thought that oil now costs the same as that backup
system is as you said scary stuff.

This greenhouse is one third the size of my others. As we started to
get
into heating season I was able to empty it and turn it off. As oil
continues to rise I am wondering if between the store (which closes at
the
end of the month) and the little greenhouse if I can close a big
greenhouse.
And if I do not need the greenhouse, I am also wondering how I turn it
into
a solar collector. I think I need to do some reading on heat pump and
transfer systems and swimming pools.

Pat

I'm thinking about it....

Depth, length, surface area of the pipe, and air volume would all be in
consideration. I would think that multiple, smaller-diameter (4", 6" ?)
pipes might be better than one large-diameter one (greater surface-to-volume
ratio, but more resistance to air flow).

I would guess that venting the hot greenhouse air in the summer should be up
and out, not down through the buried pipes. Cool air would be drawn in from
the pipes by natural convection, even without a fan.

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies. Books, Artwork, and lots of Free Info!


"Mark_OK" wrote in message
...
Is anyone using this method? Sounds intriguing. Knowing the length of the
trench to be effective would be helpful. And what about ducting the hot
air from the greenhouse down through the trench? I can see this method
working on a small hobby greenhouse.


"Ray B" wrote in message
news:6ajZi.1890$cD.932@trndny08...
About the least expensive heating method (it's good for cooling, too)
I've ever heard of was published in the AOS Bulletin in the late '70's or
'80's.

A guy had an extended trench dug 6' into the ground (or some depth
well-below his frost line), and made a long duct of large, unglazed clay
sewer pipe. One end came up through the floor of the greenhouse, and the
other end was enclosed in a structure above ground. The inlet end was
covered with a mesh and filter to prevent all but air from entering.

A thermostatically-controlled fan in the GH drew air through the
submerged pipe, where the natural subsurface temperature was in the
low-'60's F year round, which is certainly plenty warm for nighttime,
with solar heating boosting the daytime temp. In the summer, he would
switch to a cooling thermostat, drawing that same cool air. That's
certainly less maintenance than a swamp cooler!

The article also discussed how the unglazed clay absorbed the condensed
humidity in the summer, and moistened the air in the winter, but I don't
recall details.

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies. Books, Artwork, and lots of Free Info!


"alpickrel" wrote in message
oups.com...
You were smart.

My old hoophouse frame is still standing right next to the
greenhouse. It is 15 x 30 (or so). Just the metal frame right now.
It has grapes growing on it. I have had the idea in the back of my
head to cover it with insualtion and black plastic water circulating
tubes and turn it into a giant solar hot water collector/storage unit
of some kind that I can then use at night to pump the heat into the
greenhouse next to it. The heat sink can't be IN the greenhouse
because to be of any real use, whatever goes in there...a pool or
whatever..., it has to be able to get hot enough to be of use long
after the sun gets off it, so plants won't be able to be grown in
there with it. (now I get K Barrett's joke about lying to herself
about her barrel of water.)

I was staring at my electrical subpanel for the greenhouse this
afternoon and wondering what it would take to run a line large enough
to power an electric heater that would make me feel like I was not
lying to myself when I plugged it in.

I still think a good option is to find a way to drag a big warm
blanket over the greenhouse every night.

I also wondered when somebody with the know how will get the bright
idea of turning clear 6 mil greenhouse plastic film into a giant solar
electric collector sheet. I mean I spend all summer trying to REMOVE
light and heat. It would be nice to be doing something useful with
it. There is talk of a spray-on solar panel.

On Nov 9, 8:05 pm, "Pat Brennan" wrote:
When I put up my last greenhouse I needed a new power service. I had
the
power company run an extra 200 amps of service and used it for my
backup
heating system. The thought that oil now costs the same as that backup
system is as you said scary stuff.

This greenhouse is one third the size of my others. As we started to
get
into heating season I was able to empty it and turn it off. As oil
continues to rise I am wondering if between the store (which closes at
the
end of the month) and the little greenhouse if I can close a big
greenhouse.
And if I do not need the greenhouse, I am also wondering how I turn it
into
a solar collector. I think I need to do some reading on heat pump and
transfer systems and swimming pools.

Pat

How well do you think the flexible, corrugated, black plastic septic-system
pipe would work?

It's fairly thin-walled, so the heat transfer would be fairly good I would
think, and by being flexible, you could bury a bunch of coils, reducing the
amount of property that would have to be dug up.

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies. Books, Artwork, and lots of Free Info!

I don't see why that wouldn't work and would be cheaper and easier to work
with than the clay type.

"Ray B" wrote in message
news:4rZZi.4449$NC.3728@trndny07...
How well do you think the flexible, corrugated, black plastic
septic-system pipe would work?

It's fairly thin-walled, so the heat transfer would be fairly good I would
think, and by being flexible, you could bury a bunch of coils, reducing
the amount of property that would have to be dug up.

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies. Books, Artwork, and lots of Free Info!

I would guess that venting the hot greenhouse air in the summer should be
up
and out, not down through the buried pipes. Cool air would be drawn in
from the pipes by natural convection, even without a fan.

I was just thinking of keeping the humidity level up by recirculating the
air, but I see your point.

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies. Books, Artwork, and lots of Free Info!


"Mark_OK" wrote in message
...
Is anyone using this method? Sounds intriguing. Knowing the length of the
trench to be effective would be helpful. And what about ducting the hot
air from the greenhouse down through the trench? I can see this method
working on a small hobby greenhouse.


"Ray B" wrote in message
news:6ajZi.1890$cD.932@trndny08...
About the least expensive heating method (it's good for cooling, too)
I've ever heard of was published in the AOS Bulletin in the late '70's
or '80's.

A guy had an extended trench dug 6' into the ground (or some depth
well-below his frost line), and made a long duct of large, unglazed clay
sewer pipe. One end came up through the floor of the greenhouse, and
the other end was enclosed in a structure above ground. The inlet end
was covered with a mesh and filter to prevent all but air from entering.

A thermostatically-controlled fan in the GH drew air through the
submerged pipe, where the natural subsurface temperature was in the
low-'60's F year round, which is certainly plenty warm for nighttime,
with solar heating boosting the daytime temp. In the summer, he would
switch to a cooling thermostat, drawing that same cool air. That's
certainly less maintenance than a swamp cooler!

The article also discussed how the unglazed clay absorbed the condensed
humidity in the summer, and moistened the air in the winter, but I don't
recall details.

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies. Books, Artwork, and lots of Free Info!


"alpickrel" wrote in message
oups.com...
You were smart.

My old hoophouse frame is still standing right next to the
greenhouse. It is 15 x 30 (or so). Just the metal frame right now.
It has grapes growing on it. I have had the idea in the back of my
head to cover it with insualtion and black plastic water circulating
tubes and turn it into a giant solar hot water collector/storage unit
of some kind that I can then use at night to pump the heat into the
greenhouse next to it. The heat sink can't be IN the greenhouse
because to be of any real use, whatever goes in there...a pool or
whatever..., it has to be able to get hot enough to be of use long
after the sun gets off it, so plants won't be able to be grown in
there with it. (now I get K Barrett's joke about lying to herself
about her barrel of water.)

I was staring at my electrical subpanel for the greenhouse this
afternoon and wondering what it would take to run a line large enough
to power an electric heater that would make me feel like I was not
lying to myself when I plugged it in.

I still think a good option is to find a way to drag a big warm
blanket over the greenhouse every night.

I also wondered when somebody with the know how will get the bright
idea of turning clear 6 mil greenhouse plastic film into a giant solar
electric collector sheet. I mean I spend all summer trying to REMOVE
light and heat. It would be nice to be doing something useful with
it. There is talk of a spray-on solar panel.

On Nov 9, 8:05 pm, "Pat Brennan" wrote:
When I put up my last greenhouse I needed a new power service. I had
the
power company run an extra 200 amps of service and used it for my
backup
heating system. The thought that oil now costs the same as that
backup
system is as you said scary stuff.

This greenhouse is one third the size of my others. As we started to
get
into heating season I was able to empty it and turn it off. As oil
continues to rise I am wondering if between the store (which closes at
the
end of the month) and the little greenhouse if I can close a big
greenhouse.
And if I do not need the greenhouse, I am also wondering how I turn it
into
a solar collector. I think I need to do some reading on heat pump and
transfer systems and swimming pools.

Pat

My guess would be that the cooler air down in the underground pipes
will not be drawn up into the greenhouse if there is cross venting
from inlet to exhaust vents in the greenhouse above that bypasses the
pipes unless the pipes have an external inlet. Cool air will settle
to the lowest point. A fan to push or pull it through the pipes seems
required without this external inlet.

The system is analogous to swamp coolers: in order to be effective
the air coming in must be forced through the cooling structure; be it
damp crushed clay filled pipes buried in the earth or soaked pads in
front of an inlet shutter. The trench of crushed clay pipes needs one
open end to be on the outside of the greenhouse and one to be on the
inside. Actually, I would guess two inlet openings and one exhaust
are needed. One inlet is outside the greenhouse to draw in air for
cooling as vents at the top of the greenhouse exhaust the hotter air.
A second inlet is needed (and the first one closed) when air inside
the greenhouse is circulated though the pipes to warm it to the
average mean temp during "heating".

Imagine a semi-passive cooling system where a fan powered by a solar
panel forced air through the cooling pipes. For cooling, you only
need the fan to come on when the sun is out anyway.

To be ultra effective as a heater makes it bit more complicated. I
would need to look into heat exchangers and heat exchange technology
because we are talking about a primitive heat pump here. Something is
needed to 'concentrate' the BTUs before moving them up into the
greenhouse air and releasing them.

I can see the idea of a passive system being of help if I imagine that
what the ground pipes are doing is drawing the mean average air
temperature held constant by the earth at about the 6 foot depth up
into the greenhouse. This way you start your base air heating BTU
requirements at 55 degrees or so and not at whatever the current air
temperature is outside the greenhouse. In addition, heated air
naturally rises. What you are doing with the pipes when you heat is
to increase the ground's heat radiating surface. Imaging a long or
deep cave with a plastic bubble setting on top of the opening that
traps the air heated to the underground mean average temperature.

In a VERY deep tunnel, would the mean average temperature rising up
from the bottom be magma?

My thought was a recirculating system. Say an inlet at the top of the
greenhouse and an outlet at the bottom of the greenhouse, at opposite ends
of the greenhouse. A fan or fans would have to be used to force the air
through the duct work. I have a feeling that the amount of underground duct
work needed to even make a slight difference will be substantial. It
probably would be just as effective if you just sunk the greenhouse into the
ground a few feet.


"alpickrel" wrote in message
ups.com...
My guess would be that the cooler air down in the underground pipes
will not be drawn up into the greenhouse if there is cross venting
from inlet to exhaust vents in the greenhouse above that bypasses the
pipes unless the pipes have an external inlet. Cool air will settle
to the lowest point. A fan to push or pull it through the pipes seems
required without this external inlet.

The system is analogous to swamp coolers: in order to be effective
the air coming in must be forced through the cooling structure; be it
damp crushed clay filled pipes buried in the earth or soaked pads in
front of an inlet shutter. The trench of crushed clay pipes needs one
open end to be on the outside of the greenhouse and one to be on the
inside. Actually, I would guess two inlet openings and one exhaust
are needed. One inlet is outside the greenhouse to draw in air for
cooling as vents at the top of the greenhouse exhaust the hotter air.
A second inlet is needed (and the first one closed) when air inside
the greenhouse is circulated though the pipes to warm it to the
average mean temp during "heating".

Imagine a semi-passive cooling system where a fan powered by a solar
panel forced air through the cooling pipes. For cooling, you only
need the fan to come on when the sun is out anyway.

To be ultra effective as a heater makes it bit more complicated. I
would need to look into heat exchangers and heat exchange technology
because we are talking about a primitive heat pump here. Something is
needed to 'concentrate' the BTUs before moving them up into the
greenhouse air and releasing them.

I can see the idea of a passive system being of help if I imagine that
what the ground pipes are doing is drawing the mean average air
temperature held constant by the earth at about the 6 foot depth up
into the greenhouse. This way you start your base air heating BTU
requirements at 55 degrees or so and not at whatever the current air
temperature is outside the greenhouse. In addition, heated air
naturally rises. What you are doing with the pipes when you heat is
to increase the ground's heat radiating surface. Imaging a long or
deep cave with a plastic bubble setting on top of the opening that
traps the air heated to the underground mean average temperature.

In a VERY deep tunnel, would the mean average temperature rising up
from the bottom be magma?

On Mon, 12 Nov 2007 15:06:41 -0600, "Mark_OK" wrote:

My thought was a recirculating system. Say an inlet at the top of the
greenhouse and an outlet at the bottom of the greenhouse, at opposite ends
of the greenhouse. A fan or fans would have to be used to force the air
through the duct work. I have a feeling that the amount of underground duct
work needed to even make a slight difference will be substantial. It
probably would be just as effective if you just sunk the greenhouse into the
ground a few feet.



We sunk the support walls on the lean-to greenhouse - wall is depth of
house wall (basement). Filled the gh with cobbles ( football sized
rock) then topped with gravel for a level floor. We put pipes in the
cobbles - planned to force ceiling height air down thru the pipes and
let it drift up thru the cobbles to create humidity. Never did find a
way to use a fan to do this. The vertical is now gone and since the
gh floor has settled I will bet the pipes collapsed under the cobbles
as well. But the 4 foot of rock in the gh floor is a mitigating
factor on heat and cold.

I thought the article was clay pipe with the clay walls pulling
humidity from the surrounding ground water and would need a reversible
fan to force hot air in to cool and pull warmed air out to mitigate
the cold. If a loop maybe the fan only goes one way and the effect is
different by the season.
SuE
http://orchids.legolas.org/gallery/main.php

It was more me trying to save a penny than being smart. I was installing a
heat pump for summer phal forcing. The unit came with resistive backup and
it made no difference if the power company installed a 200 or 400 amp drop.
It was basically a free backup system that I knew I could not afford to run
very long. We hooted and howled as we watched the meter spin when I first
tested the unit. The fact that oil is now making the meter spin as fast has
yet to make me hoot or howl, more like moan and groan. I feel pretty silly
that my only heat pump is attack to a greenhouse not currently being heated.
I am thinking more and more that I will change that after our annual sale
this weekend.

Of all my heating options short of burning wood or coal, I think heat pumps
are my best option. I just have to figure out how to use solar to my best
advantage and come up with an efficient way to store and retrieve heat. I
think it is doable and the retrofit costs would not be that great. But with
the way the orchid economy is right now I am just not sure it is worth the
effort and money. I am afraid that doing nothing may just be conceding
defeat.

Al, I too have been thinking about greenhouse blankets for a while now. I
have done net searches looking for the perfect blanket and have not had much
luck. Pool covers and greenhouse thermal curtain are not right. I did find
a space blanket type material. It would stop IR loss but would add no R
value. We need big bolts of the material they make gloves out of, something
like Dupont's thinsolate.

Pat

"alpickrel" wrote in message
oups.com...
You were smart.

My old hoophouse frame is still standing right next to the
greenhouse. It is 15 x 30 (or so). Just the metal frame right now.
It has grapes growing on it. I have had the idea in the back of my
head to cover it with insualtion and black plastic water circulating
tubes and turn it into a giant solar hot water collector/storage unit
of some kind that I can then use at night to pump the heat into the
greenhouse next to it. The heat sink can't be IN the greenhouse
because to be of any real use, whatever goes in there...a pool or
whatever..., it has to be able to get hot enough to be of use long
after the sun gets off it, so plants won't be able to be grown in
there with it. (now I get K Barrett's joke about lying to herself
about her barrel of water.)

I was staring at my electrical subpanel for the greenhouse this
afternoon and wondering what it would take to run a line large enough
to power an electric heater that would make me feel like I was not
lying to myself when I plugged it in.

I still think a good option is to find a way to drag a big warm
blanket over the greenhouse every night.

I also wondered when somebody with the know how will get the bright
idea of turning clear 6 mil greenhouse plastic film into a giant solar
electric collector sheet. I mean I spend all summer trying to REMOVE
light and heat. It would be nice to be doing something useful with
it. There is talk of a spray-on solar panel.

On Nov 13, 8:33 am, "Pat Brennan" wrote:
It was more me trying to save a penny than being smart. I was installing a
heat pump for summer phal forcing. The unit came with resistive backup and
it made no difference if the power company installed a 200 or 400 amp drop.
It was basically a free backup system that I knew I could not afford to run
very long. We hooted and howled as we watched the meter spin when I first

Today I am working in the greenhouse and contemplating the frightening
oil bill I just got. I thought oil was $2.799 per gallon. But that's
the home heating oil price. I would have paid sales tax of 5% on that
making it $2.93 per gallon, but last year I learned that as a business
I can send the oil vendor a signed certificate to allow me to not be
taxed since the fuel is used to produce items for resale. This woke
them up to the fact that I am a business and should not be paying
"home" heating oil prices. I am now paying "Fuel; commercial tax
discount" prices of $3.094 per gallon. (NO tax on that, however) You
just can't win. Buying oil sans sales tax will now cost me almost
$500 more per season. It never dawned on me to ask if there was a
separate pricing structure before I sent the tax form in. I should
have known. I looked into electricity prices and learned that as long
as Dominion power assumes I am using all this electricity for home use
it is less expensive than what businesses pay. So I should not have
been caught by surprise here. (Electricty is looking prettier all the
time. Of course, if I run a bigger electric line in to power an
electric heater for my "commercial" greenhouse, somebody at the
electric company will notice.)

Around here oil price drops with volume no matter what you use it for. It
sounds like you need to put your oil business out for bid. I am able to get
quotes as margins so at least I can compare fruit with fruit. In some areas
you can get a quote in $/gal for the whole season, no one has ever offered
me a lock in price. Expect to save 2 to 20 cents off the 'home' prices.

Around here 'home' electric service is at most one 400 amp drop.

Pat