@clarkinks
I do like the idea of using cattle panels.
But why not just build a high tunnel through the NRCS program ?
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There is a bunch of paperwork that goes with that type of free greenhouse and in this case I want to do some experiments with no restrictions or constraints. Ive been talking with friends all of which recognize the heat problem. Propane hot water heaters & piping etc has been suggested. Wood stove , triple wall pipe with lots of creative piping has been suggested. I will take one or all of the ideas and adapt them. A gentleman is apparently raising bananas and tilapia in Kansas who is a friend of friends so I’m analyzing several methods. Anything I do this time will fall into the experimental phase. I’m aware of the program and very much appreciate the suggestion @Hillbillyhort . What i wind up doing may look nothing like what we think it does now. @JustAnne4 mentioned double plastic which is hard to argue with the effectiveness of that. Love that greenhouse setup @JustAnne4 and @Carrie has a setup that looks very similar to what I’m doing in terms of structure. It’s a strong structural design in my opinion. I may not inflate my plastic a friend suggested running pvc pipe over the first later of plastic. He suggested we create a gap with pvc pipes and the second layer of plastic on top. With a space that way there is a lot of additional insulation. A friend suggested I build a boiler because he knows I built a Wood stove from scratch for the project already. @marknmt brings up the most important thing which is the beds. I’m considering using warm water from a small five gallon propane water heater or wood burning homemade device and pumping water through the bottom of every grow box. It would be like every grow box sitting on a heat mat. The pipes would run under the grow boxes. Several friends and I are hashing the details out and everyone is aware of the problems and no one has the solution yet. Solar fans and water barrels etc. have came up many times already but there is not a solution at this time to keep this greenhouse warm enough yet for year round use of everything. @39thparallel and I talked in depth the other day and he brought up some great points of using soil warmth and partially build it into a south hillside. All of these are very good ideas to address a big problem with fluctuating heat. A friend who is heavily involved in aquaponics Aquaponics is thinking over this project and attempting to come up with some additional ideas. Much of their systems are regulated by the water temps.
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Nice… I wouldn’t mind having one of these with white plastic for overwintering potted plants.
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You could do a “ poor mans” geothermal and just dig two or three feet down like this https://m.youtube.com/watch?v=eq_mjpDbOb8
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BTW for others who may be considering this, my son got the frame off Craig’s List cheap. It was a car port cover - very sturdy and the right size.
I added the strapping for extra support for the poly.
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You folks are very creative, I enjoyed this thread!
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Had another thought i just came up with about the beds which I’ve never seen done. Let’s say I did do the poor man’s geothermal like @GeorgiaGent is suggesting but I build the table stands out of 4-6" pvc and pull my geothermal air through there and hook those pvc pipes to a geothermal system. That would keep the bottoms of the plants warm because I would pull the heat under them and not waste the space. @GeorgiaGent I’m curious about that design and now you have me thinking. @Bede if we can figure out ways to design something so valuable so cheap I hope everyone winds up with one to grow some extra food. I like Texas preppers original design it just needs some tweaking.
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@clarkinks
I have worked installing underground utility’s for many years.
I would recommend looking into using a "horizontal directional drill "to install a loop of pipe carrying water And run through a heat exchanger.
These directional drills can go very deep 20+ ft. , acssessing much more thermal mass than convetional trenching,
The machine I have worked around could drill 500 ft. Runs , like all the way across a wall mart parking lot.fully steerable for depth /direction . Leaving everything undisturbed , except for a small pit on each end.
So look into geothermal directional drill.
Other option is drilling wells and circulating water, could be a closed loop ,or open.
I have a friend in northern Ohio that has 3 wells that he circulates water through with a heat exchanger.heats his house with this,
Only power is for the pump and blower.
A well may be more useful than a horizontal pipe ? ( water ! ))
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Here is more detailed info. Kept above freezing all winter
http://www.greenfingardens.com/2013/03/new-tunnel-greenhouse-project.html?m=1
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How large do they make rolls of bubble wrap?
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@Hillbillyhort I suspect that machine is hard to find but I’m asking around. I did consider vertical instead of horizontal but the depth concerned me for several reasons. Thought I would likely hit water was the biggest detterant. Water is a good thing in Kansas so maybe I need to rethink my strategy some more.
@GeorgiaGent I think I better grab a bobcat for that job! That’s a lot of work!
@ltilton that’s a great idea making a double layer plastic and they go up to 48" ULINE - Shipping Boxes, Shipping Supplies, Packaging Materials, Packing Supplies. The problem is the plastic wouldn’t hold up long term. A friend told me to join plastic sheets just use pvc cleaner and glue and that works for greenhouse plastic.
I have wondered about using a rectangle duct covered with plastic to prevent corrosion, buried just under the ground the full length of the hoop house and then covered with green manure. This would be outside of hoop house of course. Would the compost process give off enough heat so that a small recirculating fan would help warm the hoop house in the winter, and in the summer, you would have composted manure to use. The duct would be approx. 1 ft. deep and 2 ft. wide. Any ideas.
TFN
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If you look at his other blog posts he builds his next houses with a bobcat. Actually this is the guy in Kansas you were talking about. As far as uv resistance bubble wrap there is a product called solawrap or poly keder in Europe. https://www.solawrapfilms.com/
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@TooFarNorth The old timers backed their motel t’s up a manure pile so they would start in the morning so it does definitely generate heat. I’ve had my compost piles steaming they got so hot but its really hard to regulate. Methane is also a bi product of organic material breaking down which can be captured as fuel.
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I think big, well-built piles can generate up to 160 F, but at that point they become self-limiting.
Growing up I lived a block from a planer mill, and they had filled a gully with sawdust and shavings. Steam came out of the piles all winter, and occasionally they’d break into fire. It could be that they were smoldering all the time but nearly smothered.
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@GeorgiaGent didn’t not know about that plastic that’s a great ideal! Guess the bubble wrap greenhouse was already invented @ltilton. Glad to hear they used the bobcat the next time! Kansans are fairly creative I guess because they need to be here. Once I saw a guy crack his glass fuel bowl for his ford tractor and he screwed a mason jar on there about 10 minutes later. Im going to watch a few of his other videos.
I have a friend who has done greenhouses all his life I will call shortly .
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@clarkinks
(("@Hillbillyhort I suspect that machine is hard to find but I’m asking around. I did consider vertical instead of horizontal but the depth concerned me for several reasons. Thought I would likely hit water was the biggest detterant. Water is a good thing in Kansas so maybe I need to rethink my strategy some more"))
Those directional drilling machines are fairly common around here, used by many that do underground utility work , around city’s , and for drilling under rivers or other sensitive areas. Ask the water / gas co. Who has one. ?
If you burry a pipe horizontally using air as the means to move heat, if this pipe becomes flooded with water , it is useless . ,!
Intentionally pumping Water in a pipe is a better conductor of heat than air.
It may freeze if not properly protected .
Other fluids that will not freeze can be used in a closed loop system.
A well may be a good investment ? Water in summer ,/ heat in winter.
Have seen designs where a pump is set on a timer to just pump enough to circulate then stops to allow heat transfer , like a pipe buried in your growing bed. Then circulates again
Lots of ways to do these things. Good luck
A lot to think about !
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This is one geothermal basic idea for a greenhouse
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Another option might be to use black plastic over the floor so the soil immediately underneath the greenhouse stores heat as well. I found a very fascinating article that explains the basics of geothermal http://www.geo-inc.com/geothermal-explained.html
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Geothermal Explained
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Geo Energy, geo exchange, geothermal heat pump systems; no need to be confused, they all mean the same thing. They all describe a sustainable resource that lies in the ground at your location. Here’s how it works.
A typical air conditioning system draws heat from the inside of a residence or commercial building and discharges it to the air outside using a compressor and fan. As you might expect, on hot days when the A/C is used the most, it is difficult to shed heat into the already hot outside air. The system is very inefficient and must run a long time to remove heat.Conversely in the winter, the air source heat pump tries to draw heat out of already cold air. Likewise, it struggles to draw heat from the frigid air, and must also run a long time.
Geothermal is different. At a depth of 4 to 6 feet below the frost line the ground temperature of the earth remains relatively constant throughout the year. Ground source heat pumps (GSHP) are designed to capitalize on this near constant temperature. Using a properly constructed ground heat exchanger (the ground loop or loops), they harness the thermal energy stored in the ground beneath your site.
Geothermal installations are integrated systems consisting of three major sub-systems.
Air distribution within the structure - air ducts and blowers circulate the air throughout to control the climate within the structure.
Ground source heat pump(s) - mechanical device to drive or "pump" the heat between the two other subsystems. GSHP work most efficiently when the entering liquid from the ground exchanger remains within a range of 40 to 80 degrees.
Ground heat exchangers - in-ground piping (ground loop or loops) arranged in a grid that makes contact with the earth to facilitate heat exchange. Typical ground heat exchangers are constructed of plastic tubing encased in grout creating improved thermal conductivity. These are referred to as closes loop systems. An open loop system uses groundwater from an ordinary well as a heat source. The groundwater is pumped into the GSHP unit where heat is extracted and the water is disposed of back into the ground. These open loop systems are commonly called "pump and dump" systems. Poor water quality can cause serious problems in open loop systems. Mineral deposits can build up inside the GSHP.Impurities, particularly iron, can eventually clog a return well. Because of these issues we will concentrate this discussion on the closed loop systems.
Vertical Loops: Vertical loops are used where space is limited or where soil conditions make horizontal loops impractical. Installing vertical loops require the use of a drilling rig. Multiple holes are bored at a minimum 10 feet apart. A double high density polyethylene (HDPE) pipe connected with a U-bend and filled witha mixture of water and food grade anti-freeze is inserted into each hole. The hole is filled with grout to provide good contact around the pipe and to seal the hole. The vertical pipes are then connected to a header system horizontally a few feet below the surface. The depth of the holes is dependent upon soil/rock conditions and size of the system. Although most holes are bored about 100 to 250 feet deep, there’s no “magic depth” that needs to be reached. Capacity is not based on depth: rather how much pipe is in the ground and the overall thermal conductivity of the hole.
Horizontal Loops: If adequate land is available, horizontal loops can be installed. Trenches are dug using a backhoe or trencher. HDPE pipes are inserted and the trenches are backfilled. There are various designs (slinky or race track) of horizontal loops using one, two or three circuits per trench. The more pipes in each trench, the shorter the trenches can be. Trenches normally range from 100 to 300 feet depending on the design. A typical home requires 1/4 to 3/4 of an acre for the trenches.
A variation on the horizontal loop is the directional bore loop. This type of loop is most often used in a retrofit situation to minimize disruption to the landscape. It requires special equipment to bore holes under the surface. The operator can “steer” the drill head to go deeper or shallower, or turn right or left. This machine drills at a slight angle down to a typical depth of 15 to 20 feet, then back to the surface, typically 200 ft. away. At that point, two ends of the pipe are attached to the drill bit and pulled back through the hole until the pipe is buried. This technique allows the loop to be placed underneath homes, basements, wooded lots or even swimming pools.
Pond Loops: If an adequately sized body of water is close to your home, a pond loop can be installed. A series of sealed HDPE pipes containing a mixture of water and anti-freeze can be coiled and sunk to the bottom. A 1/2 acre, 8-foot-deep pond is usually sufficient for the average home. Ideally, the pond should be close to the home (less than 200 ft.). If the pond is farther from the home, the benefit of using a pond loop is reduced due to added trenching, materials and pumping costs.
Pond loop coils are connected together on dry land, and then floated into location. Once filled with fluid, they will sink to the bottom and remain there. Generally, a 300 ft. coil is used for each ton of capacity. This is less pipe than is used in an earth loop because water is a better conductor of heat energy. Pond loops are a cost effective way to install a geothermal system, because trenching is limited to only the supply and return piping from the pond to the house.
How about lower energy bills? Heat from the ground is free, and the only electricity needed is for moving that heat between your home and the ground. According to the Geothermal Heat Pump Consortium, a geothermal system can lower your heating bill up to 50 percent and lower your cooling bills up to 30 percent. This could mean a payback in as little as two to seven years! Ground-source heat is a naturally renewable energy source and friendly to the environment.
Geothermal systems work very well in below zero temperatures; and when the equipment and loop field are sized correctly, the electrical resistance back up is minimal. The geothermal system in your home is specifically designed to account for the climate and your home’s heating and cooling load. Geothermal systems are very efficient in northern climates and work just as efficiently as those in southern zones. As with any home heating and cooling, adequate insulation and overall weatherization are key factors in lowering energy consumption.
Some frequently asked questions about geothermal.
“What makes a geothermal system different from conventional heating and cooling systems?”
Unlike ordinary systems, Geothermal systems do not burn fossil fuel to generate heat; they simply transfer heat to and from the earth to provide a more efficient, affordable and environmentally friendly method of heating and cooling. Typically, electrical power is used only to operate the unit’s fan, compressor and pump.
“Is the efficiency rating actual or just a manufacturer’s average?”
All heating and cooling systems have a rated efficiency from a U.S. governmental agency. Fossil fuel furnaces have a percentage efficiency rating. Natural gas, propane and fuel oil furnaces have efficiency ratings based on laboratory conditions. To get an accurate installed efficiency rating, factors such as flue gas heat losses and cycling losses caused by oversizing, blower fan electrical usage, etc., must be included.
Geothermal heat pumps as well as all other types of heat pumps, have efficiencies rated according to their coefficient of performance or COP. It’s a scientific way of determining how much energy the system produces versus how much it uses. Most geothermal heat pump systems have COP’s of 3 to4.5. That means for every one unit of energy used to power the system, 3-4.5units are supplied as heat. Where a fossil fuel furnace may be 78 to 98 percent efficient, a geothermal heat pump is about 400 percent efficient. Some geothermal heat pump manufacturers and electrical utilities use computers to accurately determine the operating efficiency of a system for your home or building.
“Do geothermal systems require much maintenance?”
No. Geothermal systems are practically maintenance free.When installed properly, the buried loops will last for generations. And the other half of the operation - the unit’s fan, compressor and pump - is housed indoors, protected from the harsh weather conditions. Usually, periodic checks and filter changes are the only required maintenance.
“What does geothermal mean for the environment?”
Geothermal systems work with nature, not against it. They emit no greenhouse gases, which have been linked to global warming, acid rain and other environmental hazards. Geothermal Eco Options uses an environmentally friendly anti-freeze exclusively in all the ground loops that we install in case of the unlikely event of a leak.
“How does a geothermal heat pump work?”
Anyone with a refrigerator or air conditioner has witnessed the operation of a heat pump, even though the term heat pump may be unfamiliar.All of these machines, rather than making heat, take existing heat and move it from a lower temperature location to a higher temperature location.Refrigerators and air conditioners are heat pumps that remove heat from colder interior spaces to warmer exterior spaces for cooling purposes. Heat pumps also move heat from a low-temperature source to a high-temper space for heating.
An air-source heat pump, for example, extracts heat from outdoor air and pumps it indoors. A geothermal heat pump works the same way,except that its heat source is the warmth of the earth. The process of elevating low-temperature heat to over 100 degrees Fahrenheit and transferring it indoors involves a cycle of evaporation, compression, condensation and expansion. A refrigerant is used as the heat-transfer medium which circulates within the heat pump. The cycle starts as the cold liquid refrigerant passes through a heat exchanger (evaporator) and absorbs heat from the low-temperature source (fluid from the ground loop). The refrigerant evaporates into a gas as heat is absorbed.
The gaseous refrigerant then passes through a compressor where the refrigerant is pressurized, raising its temperature to more than 180degrees. The hot gas then circulates through a refrigerant-to-air heat exchanger where heat is removed and pumped into the building at about 100degrees. When it loses the heat, the refrigerant changes back to a liquid. The liquid is cooled as it passes through an expansion valve and begins the process again. To work as an air conditioner, the system’s flow is reversed.
“Does a geothermal system heat and cool?”
One thing that makes a geothermal heat pump so versatile is its ability to be a heating and cooling system in one. With a simple flick of a switch on your thermostat, you can change from one mode to another.
“Can a geothermal system also heat water?”
Yes. Some geothermal heat pumps can provide all of your hot water needs on demand at the same high efficiencies as the heating/cooling cycles. An option called a desuperheater can be added to most heat pumps. It will provide significant savings by heating water before it enters your water tank.
“Do I need separate ground loops for heating and cooling?”
No. The same ground loops work for both. To switch heating to cooling, or vice versa, the flow of heat is simply reversed.
“Does the underground pipe (ground loop) system really work?”
The buried pipe, or ground loop, was an important technical advancement in heat pump technology. The idea of burying pipe in the ground to gather heat energy originated in the 1940’s. New heat pump designs and more durable pipe materials have been combined to make geothermal heat pump systems the most efficient heating and cooling systems available.
“What is a closed loop system?”
A closed (ground) loop system uses a continuous loop of buried high density polyethylene pipe (HDPE). The HDPE pipe is connected to the indoor heat pump to form a sealed, underground loop through which an environmentally friendly anti-freeze and water solution is circulated. A closed loop system constantly re-circulates its heat-transferring solution in pressurized polyethylene pipe. Many closed loop systems are horizontally bored in areas adjacent to the building. However, where adequate land is not available, loops are vertically bored. Any area near a home or business with appropriate soil conditions and adequate square footage will work.
“How long will the ground loop last?”
Closed loop systems should be installed using only high density polyethylene pipe. HDPE is expansive, therefore it is able to expand and contract. Properly installed, these pipes will last for 50 years or more.They are inert to chemicals normally found in the soil and have good thermal conducting properties. PVC pipe is not expansive and therefore should never be used in a ground loop.
“How are the pipe sections of the loop joined?”
Pipe sections are joined by thermal fusion. Thermal fusion involves heating the pipe connections and then fusing them together to form a joint that’s stronger than the original pipe. This technique creates a secure connection to protect from leakage and contamination.
“Will the ground loop affect my lawn or landscape?”
No. Research has proven that ground loops have no adverse effects on grass, trees or shrubs.
“I have a nearby pond; can I put a loop in it?”
Yes, if it’s deep enough and large enough. A minimum of six feet in depth at its lowest level during the year is needed for a pond loop to be considered. The amount of surface area required depends on the heating and cooling load of the structure.
“Can I install the ground loop myself?”
It’s not recommended. Good earth-to-loop contact is very important for successful loop operation. Nonprofessional installations may result in less-than-optimum loop system performance.
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