Suggestions for sustainable and (as much as possible) inexpensive Greenhouse heating solutions

I live in Oklahoma, so we do not get extreme "Northern" winters here, but we do get a lot of nights in the teens and even down to single digits a few times each winter.  I just recently purchased a Hoop bender to turn my old chain link fence top railing into Greenhouse ribs.  I am weighing my options between the less expensive poly wrap and possibly something better like ETFE film.  I am hoping this hoop house will serve me for several years while I work to build a more long-term Greenhouse that will likely have Insulated North, East and West walls, if not even earth-bermed walls.

I have looked at lots of different possible ways to heat my hoop house, but before I try something I have never done before and end up learning "the hard way" I would much rather ask advice from folks who have already be down this road or one similar to it.  I do not plan to run a Propane line into the greenhouse to heat with.  I may consider some form of small heater on a 5-10 gallon propane tank for emergency overnight help, but would prefer suggestions that are more sustainable than Propane.

I have looked at various configurations for earthtube, and I do have access to a Backhoe to make the digging a lot easier, and we have good sandy loam here, without much rock, so digging is not an extreme problem, as it may be in some places.  I have also looked at a couple different Rocket Mass Heater applications that seem plausible.  But whether or not I have looked at or mentioned an idea doesn't matter, because I KNOW that I am (at best) a Newbie extraordinaire.  

So please, offer met suggestions for heating my greenhouse.  I do have plenty access to firewood, although I would prefer not to be setting an alarm to go out to the greenhouse overnight if possible.  Please educate me on what my options are.

Thanks in advance for your advice!

Hey Jimmy; I vote for a RMH!
We have been using one here in northern Montana in our greenhouse for 7 years!
The only way to go!
I just recently switched from an 8" J tube to a 6" batch box makes things even easier.

Are you thinking just shoulder seasons or all winter long?

Jimmy Burt wrote:I live in Oklahoma, so we do not get extreme "Northern" winters here, but we do get a lot of nights in the teens and even down to single digits a few times each winter.  I just recently purchased a Hoop bender to turn my old chain link fence top railing into Greenhouse ribs.  I am weighing my options between the less expensive poly wrap and possibly something better like ETFE film.  I am hoping this hoop house will serve me for several years while I work to build a more long-term Greenhouse that will likely have Insulated North, East and West walls, if not even earth-bermed walls.

I have looked at lots of different possible ways to heat my hoop house, but before I try something I have never done before and end up learning "the hard way" I would much rather ask advice from folks who have already be down this road or one similar to it.  I do not plan to run a Propane line into the greenhouse to heat with.  I may consider some form of small heater on a 5-10 gallon propane tank for emergency overnight help, but would prefer suggestions that are more sustainable than Propane.

I have looked at various configurations for earthtube, and I do have access to a Backhoe to make the digging a lot easier, and we have good sandy loam here, without much rock, so digging is not an extreme problem, as it may be in some places.  I have also looked at a couple different Rocket Mass Heater applications that seem plausible.  But whether or not I have looked at or mentioned an idea doesn't matter, because I KNOW that I am (at best) a Newbie extraordinaire.  

So please, offer met suggestions for heating my greenhouse.  I do have plenty access to firewood, although I would prefer not to be setting an alarm to go out to the greenhouse overnight if possible.  Please educate me on what my options are.

Thanks in advance for your advice!

Hi Jimmy,

Personally I’d strongly consider two earth cooling tubes run six feet under ground. I’d recommend run lengths of at least 100 feet and six inch PVC.

As you know, they will heat outdoor air to ground temperature of about 50 degrees F. This will help warm your greenhouse.

I’d also recommend earth sheltering and insulating the greenhouse. Although that may be a project you’ll complete in years to come. At the very least be sure to insulate the structure at night—that is, install Aluminet shade cloth that you can pull into place at night to hold the heat in.

It does a great job of reflecting infrared radiation that’s trying to escape from your greenhouse at night back into the greenhouse.

My book on Chinese greenhouses describes a number of other steps you can take to keep the greenhouse warmer at night.

If you just want to grow lettuce and other leafy vegetables throughout the winter, I’d strongly recommend you employ the Four-season harvest technique. All you need to do is install mini hoop houses over your grow beds within the greenhouse.

Hi Thomas and Jimmy, we are in a similar conundrum. We want a greenhous and will likely have to provid supplemental heat for a few days each year.

W be considered diverting rain water to barrels for thermal mass. How about the days in a row that not much sun enters?

https://bradford.missouri.edu/passive-solar-greenhouse/

Not sure where you be. The above site is something to consider

Looking forward to hearing more solutions.

Sena Kassim wrote:Hi Thomas and Jimmy, we are in a similar conundrum. We want a greenhous and will likely have to provid supplemental heat for a few days each year.

W be considered diverting rain water to barrels for thermal mass. How about the days in a row that not much sun enters?

https://bradford.missouri.edu/passive-solar-greenhouse/

Not sure where you be. The above site is something to consider

Looking forward to hearing more solutions.

Thanks for the info.

My long-term plan is for a passive solar design, but my near term reality is starting with a simpler hoop house.  The hoop house is what I’m seeking the heat suggestions to support.

I do love the passive solar designs.  Www.FriendlyAquaponics.com recommend a Chinese style passive solar greenhouse as well. That was the first place I heard of passive solar or Chinese style greenhouses.

Dan Chiras wrote:

Hi Jimmy,

Personally I’d strongly consider two earth cooling tubes run six feet under ground. I’d recommend run lengths of at least 100 feet and six inch PVC.

As you know, they will heat outdoor air to ground temperature of about 50 degrees F. This will help warm your greenhouse.

I’d also recommend earth sheltering and insulating the greenhouse. Although that may be a project you’ll complete in years to come. At the very least be sure to insulate the structure at night—that is, install Aluminet shade cloth that you can pull into place at night to hold the heat in.

It does a great job of reflecting infrared radiation that’s trying to escape from your greenhouse at night back into the greenhouse.

My book on Chinese greenhouses describes a number of other steps you can take to keep the greenhouse warmer at night.

If you just want to grow lettuce and other leafy vegetables throughout the winter, I’d strongly recommend you employ the Four-season harvest technique. All you need to do is install mini hoop houses over your grow beds within the greenhouse.

Thank you.

I am a big fan of the earth tubes idea.

This greenhouse will just be a hoop house, likely using foil backed foam sheeting on the north side (foil side facing inward to help reflect the low angle light from the south back into the house). The end walls will be well insulated also.

I had not heard of the Aluminet before was was looking into have an additional tarp layer to roll over the hoop at night. I will definitely look into that though.

thomas rubino wrote:Hey Jimmy; I vote for a RMH!
We have been using one here in northern Montana in our greenhouse for 7 years!
The only way to go!
I just recently switched from an 8" J tube to a 6" batch box makes things even easier.

Are you thinking just shoulder seasons or all winter long?

Ideally all winter, but that may be more for the later, more developed greenhouse, and the hoop may only serve the shoulder seasons.

Do you have any posts sharing your greenhouse RMH? I would love to see how you’re utilizing it for best effect.

I am hoping that relocating some of our chickens to live under the hoophouse benches as winter quarters will provide enough supplemental heat. I'm in a fairly mild climate though. Winter temperatures usually hover around freezing with maybe a week or two of colder temperatures.

One of our future projects will be a passive solar greenhouse built into the side of the hill. For that one we would run tubing into the hill for geothermal heating and maybe put in a trench or pit for diverting the cold air. Looking forward to seeing what comes out of the Wheaton Lab greenhouse experiment which should be completed before we're ready to make plans.

Andrea Locke wrote:
One of our future projects will be a passive solar greenhouse built into the side of the hill. For that one we would run tubing into the hill for geothermal heating and maybe put in a trench or pit for diverting the cold air. Looking forward to seeing what comes out of the Wheaton Lab greenhouse experiment which should be completed before we're ready to make plans.

Thanks for sharing!

The idea of having the chickens (I assume in pens) under the benches is definitely interesting.  I had not thought of that previously, but I am looking at low raised beds in the hoop house, and likely primarily Aquaponics in the PSG "of my future plans". But we will see what happens as we keep moving forward.

I LOVE the idea of the PSG built into the side of the hill.  My property is very flat, and that is why I eventually plan to go with the Berms on the West, North and East sides of my later Greenhouse plans.  Having the Cold sink "trench" to pull the cold air away from your crops is also a great idea, or so I have read.  I have yet to actually build any greenhouse. :-) But I am getting close.