Well ya didn't get any attention on this.....so I'll toss out a few questions/ideas/thoughts/"advice"....

Yer on the Front Range...right?

Is this structure made of pvc/metal "hoops" with plastic sheeting stretched over it...or something else?

IMO...a structure constructed from plastic sheeting will be "iffy". Heavy snow will collapse it, arctic cold will penetrate it....etc..etc..etc.....especially if it is free-standing.

Heat.....not light....will be your challenge, IMO. Wouldn't you wanna do a Winter bloom cycle on the natural Sun/light cycles of 12/12 anyway? That is My dream. A GH with a Winter crop.... all natural light...no HPS/etc....

Ideas:

Can you attach this structure to your home/dwelling? If you can it will be far easier to heat/keep warm. A box fan blowing out from the house...where it's 65-68F will raise temps substantially in the size of structure you are targeting. If you've ever been in a large/commercial GH you may remember seeing the clear/puffed out tubes of warm air they funnel into the sppace...this is the same idea....

Insulating a few feet up from the ground on the side walls with reflectix/etc..will also help

Go WOODSTOVE over fireplace. Burn times are far longer and there's no comparison for heat output. Hell...get a wood/coal stove if you can find one..... talk about a slow/hot burn....

The ground will be far colder than your Summer experience////possibly frozen...and that is something that will pull temps down iside the GH. Insulating the floor is a good idea if this seems like a permanent/ongoing project.... Blue foam boards and plastic with 4-6" gravel over the top works well. (this is what we did up here for a school GH I helped build years ago that worked well.....)

Gotta say I am intrigued....but also gotta say that it will be a challenge...and there is good reason you didn't get lots of advice...cus i'm not sure anyone has tried it that I know of.... other than HUGE GH's .....with central heat/etc......


I sure wouldn't make it my ONLY crop..... but it would be a fun thing to attempt....

good luck

s h

bevin said:

I am about to transform my 10' x 10' hoop house into a 10' x 16'. I am looking to be able to grow out here year round and am looking for any advice or information on being able to accomplish this. I've just been shown a great idea for a fire place within the unit. But am in need of ideas for suplimenting the light on longer without killing my already high electric bill.

Click to expand...

a few CFLs

Im in CO Springs here my front yard is pikes peak and my backyard is plains. Im in an area that the weather likes to go around us, and haven't had heavy snows or arctic conditions.The placement of my GH is now next to a fence with poplars behind it. I still get full sun but also get some wind and snow blockage at the same time. I Was thinking of starting clones inside under floros till there were about 12" tall then transferring them to the GH outside to finish off there bloom cycle. My GH is PVC hoop style covered with 6 mil' plastic. Would be building a fire place inside the structure using cinder blocks. and having it vent outdoors. or usein our existing talavera stove to heat the unit. The question is now? how would i keep either the ground warm or the pots that my plants would sit in warm enough to stop stress from occuring

It sounds like you've been in your house/location for many years and know the weather well.

Can't wait to see what ya come up with and how it works out for ya.

Once I get it up I will definitely post pictures.

I missed this thread, sorry.

If you have electric power you have endless possibilities. I agree with SH about a wood stove over a fireplace. I built a fireplace because I had no money to purchase a wood stove...and had 7 hours to get it up and running before a cold front came in. The cinderblocks (filled with cement) are actually very good at storing thermal mass much like a woodstove. Long after my fires are out the cinderblocks are still hot/warm to the touch.

I'd bulk up that PVC hoop house with long horizontal bracing using 2x2's and further brace up the ends.
6ml plastic is almost zero R-factor. Honestly I think it will be very difficult to keep it warm in there at night. Last night I had temps in the teens and lit a fire at 7 pm in my GH. I checked temps at 11 pm and inside it was 40 (not bad). I lit another fire anyways and checked in on it again at 2:30 am. It was 3o degrees and IMO thats about as low as you want it without damaging your plants. I lit another fire and checked things again at 5 AM and again it was 30 degrees inside. I lit it once more. Three separate fires, getting up in the middle of the night.. that's a lot of work...and not real good sleep. I can not imagine trying to keep temps up in Jan or Feb and doing that every single night.

If you go with pots you could use some type of electric grids (like electric blankets) and wrap the pots up. If you plant directly in the ground you will have to do some more work to keep the soil warm. Do a google for constructing a "cold sink." Basically this a ground area that is dug deeper than your garden area which acts as a cold sink for cold to gather thus keeping the heat above. There are also a few ways to heat the soil by burying flexible drainpipe underground and inducing heat into the hosing.

For winter the challenge is to keep it warm at nights. It will be a breeze to keep temps up in the daytime. Yesterday in my GH (in the day) it was 30 degrees outside and 75 degrees inside with one vent cracked open. I think the solution for a winter greenhouse is to build it out of wood (more beefy) and use some type of insulating covering like Solexx (double layers). Cover the north facing side with insulation and sheathing...as there is no need to use plastic where the sun don't shine. Maybe evn paint the interior north wall black as well (or another dark color..I like forest green). I tend to lean towards some type of electric grids and keep the plants in pots instead of in the soil. (less work) And if need be, the potted plants can easily be hustled indoors should the weather become super-nasty or if encountered by a growers worst nightmare, the dreaded power outage. As far as extra lighting goes? You can use T-5's for a cheap supplements of lighting. HIDs will cost more but those will also be a nice heat source as opposed to T-5s. If you can afford it I'd lean towards HPS or MP just because of the heat factor. They eat up more electrical juice though (than T-5s). Another option is heating the GH with those oil/electric heaters. Plain electric heaters (like baseboard heaters) are the worst type of heat in regards to cost-to-run factors.

It surely is a challenge. The thing to consider is how much money is this going to cost you to grow your own. Look at you initial start up fees (equipment and stuff) and then factor in your other costs like electric bills, cost of wood, etc...and don't forget to include your actual labor (personal time) that will be needed to keep everything sweet and productive. There sometimes comes a time where all your work and investments just won't make it worth your while. Therefore..try to keep it simple as possible..which often seems to be the most inexpensive way. It often comes down to creativity and trial and error.

Heres something you may want to think about: You could also tap into your homes heating system (ie gas furnance) and tee off a heat duct and pipe it directly into your GH. But again you'd have to monitor inside GH temps and see if they would hold you above 32 degrees.

SH made a good suggestion. An attached grow room off your house would be nice. And you use heat from your main house into the grow room. IMO this would be the cats ass. (I wonder how that expression came to be...cats ass.)

I COULD attempt a winter grow in my current set-up but the amount of labor involved steers me away from taking on the challenge. You would have to be married to your grow, never miss one night and constantly be a slave to your commitment. A damn rough row to hoe but OTOH not impossible. either. Lets us know what ya do and good luck.

This is probably too much of a rigmarole and expense at the moment, but maybe long term you could look in to ground source heating or ground-coupled heat exchangers. You would have to bury loads of pipes in your plot, if you could do the work yourself it might save quite a bit, Don't know how big your plot is. Can do a similar thing with a deep bore-hole I think.

If you got enough area you could save on your household heating too, works beat with underfloor heating I understand.

Peace.

I recently saw a video of a Canadian GH farmer who uses Christmas lights to heat his GH. Just a few strings. He likes them because they don't get very hot and draw low wattage. I know a WA fellow who has a passive heating system where he traps groundheat, but damn if I can remember how he does it. Water barrels, a pumping system, stuff like that. This guy is growing roses and stuff because his sister runs a vineyard and rose garden/nursery out there, so they've got the funds to dump into a right proper set-up, like Drenge is saying.

Doesn't stone make a good heat sink? And the double-paning thing, is reminding me of an article I read in Mother Earth News on passive solar heating a barn by making this glass or Plexi wall... I wish I could remember where it is because it had schematics showing how you'd create the airflow necessary to get the workspace warmed up.

Remembering: Sometimes I haz eet, sometimes I don't!

Here is a couple pictures of what I am putting together now