Bananas.org - View Single Post - Rethinking the greenhouse concept

sunfish · 07-24-2014, 10:49 AM

A) Build it Solar - Solar Sunspaces and Greenhouses B) Permaculture Greenhouse - http://www.midwestpermaculture.com/G...escription.php
C) Calculations - http://numsum.com/tag/show/greenhouse
D) SunnyJohn - interesting array of info - Subterranean Heating and Cooling System Explained

Author Comment

Ingevald

Avatar / Picture

Registered: 01/20/08
Posts: 273
Posted 10/29/08 #1
This is a followup note to my original posting Fresh figs grown for market in Missouri regarding the growing of fresh figs for market in Missouri. I have not had time to process all of the information from the visit nor have I yet had time to research the topic in great depth. I will do my best to explain my observations from my short but impressive visit. (This is also posted on G.W.)
The first of his two 30’x100’ greenhouses is filled with figs. It is heated with vegetable oil and is cooled by the raising of a curtain on both sides of the greenhouse (cross ventilation) with an electric motor that runs off of a battery that is charged by a solar panel. The motor drives a worm gear that pulls a cable and pulley system that raises the side curtains (both sides) of the greenhouse, allowing for cross ventilation. It cools down adequately on hot days.
His "solar geothermal" hoophouse contains about %25 figs and the rest are vegetables and strawberries. This house is cooled and heated by taking advantage of the thermal mass under the greenhouse - a subterranean heating and cooling system. The earth under the greenhouse was excavated to install two heat exchange systems - two is needed to maintain maximum efficiency. Each system is composed of 16 rows of 4" flexible perforated tubes, spaced 1 foot apart. The 4” pipes connect to a larger pipe (15”??). The two larger pipes connect to a 20” vertical pipe for input and output. (see my basic drawing "Photo 15 link)

Air is blown down one 20” pipe and comes out the opposite corner. During the day the fans run, pushing the the warm and humid air through the pipes. Mold, fungus, and mildew does not form in the tubes because it is an aerobic system. The nearly continuous air flow plus the perforated pipes contribute to the health of the system. The perforated drainage pipe allows moisture and heat to transfer between the soil and the pipe. This also warms up the soil which is good for the roots, especially when front and back end seasonal temperatures are cold. (He planted some fig cuttings this spring and they are already making figs on their 5-6' stems! See the photo below)
At nighttime the fans can run and the heat that was stored in the ground becomes available to warm the greenhouse. Warm moist air is produced by the system at night.
There is also a thermostatically controlled exhaust fan mounted on the back wall to pull out excessive heat during the day. The fans that blow air through the underground grid are also controlled by a thermostat. I am not sure of the exact temperature levels that are set for day and night time running cycles. (He has a goal to someday run these fans off of solar electricity if I remember correctly)
The coldest that it got last winter was about 2 below zero F. The geothermal system kept the greenhouse around 43 deg during this coldest time. That is what really impressed me! It is like having a Mediterranean microclimate all year.
The outside of the greenhouse has a thick blue styrofoam insulation skirt that extends about 2 feet outward on the ground level, then extends about 5 feet into the ground. This is more important in the winter time, keeping the frozen ground at some distance from the edge of the greenhouse. He has a double layer of plastic that is inflated, especially in the winter months. This adds some insulation value.
The minimum sized greenhouse that will will function this way is 1000 sq feet. Small houses end up with more exposed surface area relative to the amount of underground heat storage.
If you are serious about this type of greenhouse - shop around. There are huge differences in price with little difference in quality in some cases. Also, thoroughly research your plan. Fossil fuel heated greenhouses are wasteful and expensive to run - this alternative design really saves a lot of money and energy in the long term.
Here are some photo descriptions (probably are not in order of the uploads)
This first photo shows the dense fig tree growth in his first greenhouse.

The second photo shows the outside of the first greenhouse with the movable curtain to allow ventilation.

The third photo shows one of two exit vents from the underground system Clean dry fresh air!

The fourth photo show an input fan next to a bed of strawberries.

The fifth photo shows the first years growth from cuttings - now five to seven feet tall and ripening figs. The warm soil makes them grow fast.

The last photo shows the outside of the first greenhouse with the ventilation curtain open. There is a forest of Brunswicks growing outside.

A) Build it Solar - Solar Sunspaces and Greenhouses B) Permaculture Greenhouse - http://www.midwestpermaculture.com/G...escription.php
C) Calculations - http://numsum.com/tag/show/greenhouse
D) SunnyJohn - interesting array of info - Subterranean Heating and Cooling System Explained
E) Columbia Tribune - another article about Ivan’s greenhouses - http://columbiatribune.com/2008/Sep/20080912Busi009.asp

By placing your curser over the photos below, the title will likely make an appearance.

Ingevald

07-24-2014, 10:49 AM	#8 (permalink)
sunfish Banned sunfish's Photo Gallery Location: San Diego Find me on the map! Zone: 9-11 Name: Tony Join Date: Apr 2008 Posts: 18,429 BananaBucks : 949,288 Feedback: 8 / 100% Said "Thanks" 3,210 Times Was Thanked 20,591 Times in 7,760 Posts Said "Welcome to Bananas" 2,716 Times	Re: Rethinking the greenhouse concept - advice & thoughts welcomed A) Build it Solar - Solar Sunspaces and Greenhouses B) Permaculture Greenhouse - http://www.midwestpermaculture.com/G...escription.php C) Calculations - http://numsum.com/tag/show/greenhouse D) SunnyJohn - interesting array of info - Subterranean Heating and Cooling System Explained Author Comment Ingevald Avatar / Picture Registered: 01/20/08 Posts: 273 Posted 10/29/08 #1 This is a followup note to my original posting Fresh figs grown for market in Missouri regarding the growing of fresh figs for market in Missouri. I have not had time to process all of the information from the visit nor have I yet had time to research the topic in great depth. I will do my best to explain my observations from my short but impressive visit. (This is also posted on G.W.) The first of his two 30’x100’ greenhouses is filled with figs. It is heated with vegetable oil and is cooled by the raising of a curtain on both sides of the greenhouse (cross ventilation) with an electric motor that runs off of a battery that is charged by a solar panel. The motor drives a worm gear that pulls a cable and pulley system that raises the side curtains (both sides) of the greenhouse, allowing for cross ventilation. It cools down adequately on hot days. His "solar geothermal" hoophouse contains about %25 figs and the rest are vegetables and strawberries. This house is cooled and heated by taking advantage of the thermal mass under the greenhouse - a subterranean heating and cooling system. The earth under the greenhouse was excavated to install two heat exchange systems - two is needed to maintain maximum efficiency. Each system is composed of 16 rows of 4" flexible perforated tubes, spaced 1 foot apart. The 4” pipes connect to a larger pipe (15”??). The two larger pipes connect to a 20” vertical pipe for input and output. (see my basic drawing "Photo 15 link) Air is blown down one 20” pipe and comes out the opposite corner. During the day the fans run, pushing the the warm and humid air through the pipes. Mold, fungus, and mildew does not form in the tubes because it is an aerobic system. The nearly continuous air flow plus the perforated pipes contribute to the health of the system. The perforated drainage pipe allows moisture and heat to transfer between the soil and the pipe. This also warms up the soil which is good for the roots, especially when front and back end seasonal temperatures are cold. (He planted some fig cuttings this spring and they are already making figs on their 5-6' stems! See the photo below) At nighttime the fans can run and the heat that was stored in the ground becomes available to warm the greenhouse. Warm moist air is produced by the system at night. There is also a thermostatically controlled exhaust fan mounted on the back wall to pull out excessive heat during the day. The fans that blow air through the underground grid are also controlled by a thermostat. I am not sure of the exact temperature levels that are set for day and night time running cycles. (He has a goal to someday run these fans off of solar electricity if I remember correctly) The coldest that it got last winter was about 2 below zero F. The geothermal system kept the greenhouse around 43 deg during this coldest time. That is what really impressed me! It is like having a Mediterranean microclimate all year. The outside of the greenhouse has a thick blue styrofoam insulation skirt that extends about 2 feet outward on the ground level, then extends about 5 feet into the ground. This is more important in the winter time, keeping the frozen ground at some distance from the edge of the greenhouse. He has a double layer of plastic that is inflated, especially in the winter months. This adds some insulation value. The minimum sized greenhouse that will will function this way is 1000 sq feet. Small houses end up with more exposed surface area relative to the amount of underground heat storage. If you are serious about this type of greenhouse - shop around. There are huge differences in price with little difference in quality in some cases. Also, thoroughly research your plan. Fossil fuel heated greenhouses are wasteful and expensive to run - this alternative design really saves a lot of money and energy in the long term. Here are some photo descriptions (probably are not in order of the uploads) This first photo shows the dense fig tree growth in his first greenhouse. The second photo shows the outside of the first greenhouse with the movable curtain to allow ventilation. The third photo shows one of two exit vents from the underground system Clean dry fresh air! The fourth photo show an input fan next to a bed of strawberries. The fifth photo shows the first years growth from cuttings - now five to seven feet tall and ripening figs. The warm soil makes them grow fast. The last photo shows the outside of the first greenhouse with the ventilation curtain open. There is a forest of Brunswicks growing outside. A) Build it Solar - Solar Sunspaces and Greenhouses B) Permaculture Greenhouse - http://www.midwestpermaculture.com/G...escription.php C) Calculations - http://numsum.com/tag/show/greenhouse D) SunnyJohn - interesting array of info - Subterranean Heating and Cooling System Explained E) Columbia Tribune - another article about Ivan’s greenhouses - http://columbiatribune.com/2008/Sep/20080912Busi009.asp By placing your curser over the photos below, the title will likely make an appearance. Ingevald Last edited by sunfish : 07-24-2014 at 10:52 AM.