Oregon Greenhouse Build 2017

Humanrob

Well-Known Member
It was my hope to build a greenhouse this year, but we needed to put if off a year. Ours would be similar to yours, probably smaller (more like 10x16).

What is your plan for the floor? With 50a service indicated, perhaps you are planning ahead for a dehumidifier? I think that's necessary in Oregon, but that only works efficiently in at least a relatively sealed system... and for me the floor (i.e. sealing out the ground) has been the weak link.
 

Houstini

Well-Known Member
What is your plan for the floor? With 50a service indicated, perhaps you are planning ahead for a dehumidifier
50a sub panel should cover me if I choose to add lighting in the future, will also be for service plugs for fans, controllers and exhaust system. Have gas nearby too in case I want to add a heater for frost protection.

Got enough white membrane roofing to lay down temporary this year, I won't bother welding it together as it's a bunch of 3' wide rolls. If it works out I'd like to use that material for a permanent floor and get a roofer to install it properly and have a drain ran out.

If you are trying to use your ventilation system to regulate temperature, a dehumidifier would not be useful. Exhaust system designed for 1 air exchange per minute.

I'm only putting 5 in there, I think I should have enough room for free air movement. I hope
 

Humanrob

Well-Known Member
If you are trying to use your ventilation system to regulate temperature, a dehumidifier would not be useful. Exhaust system designed for 1 air exchange per minute.
I haven't actually tried to run a greenhouse in this climate, so I'm piecing together some of my experience with outdoor here, working in other people's greenhouses, and things I've read or heard. I'm thinking that the ventilation system will be effective at reducing heat build up during the summer, but come fall when it gets cold and wet out and the vents are closed, I might get a humidity build-up. It's possible that I could use heat to control that, but there are those in between days (or weeks) when its too warm to run heat but too damp to pull outside air through. I'm trying to account for all conditions, but I don't have this completely figured out yet.

Sounds like with your set up you'll be able to compensate for just about anything.
 
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Bugeye

Well-Known Member
Design it so you can open up sections of wall or have huge windows you can open. You won't need as much fans with this approach. I eventually got there one modification at a time on mine!

Good luck with the project, looks like a lot of fun!
 

Houstini

Well-Known Member
The only thing I'm concerned about is exactly what humanrob brought up, using airflow to regulate temperatures while pulling in damp fall air. A gas fired makeup air on the intake side?
 

slow drawl

Well-Known Member
Might want to think about a shade cloth for those hot sunny days. I bought an Aluminet 50% shade cloth, and is the only way to keep temps down on those 90+ days. I run a swamp cooler on a temp controller set to come on around 80 degrees. My exhaust fan on another controller set at 85 if the swamp cooler can't keep up. During the fall I don't bring in volume of outside air, just run the dehuey and a small elec. heater. And plenty of fans for air circulation. This works well for me though my GH is only a 10 by 14 considerably smaller than what you have planned.
 

DG1959

Well-Known Member
You can kind of see what I have done. Each side can roll up plus if need be the top can roll also..Plus 2 fans... double 6mil. plastic for roof is a must.
Last year buds where huge! BUT! a lot friends lost bud to rot because of humidity. I was lucky, lost very little. Ventilation 100% better this time.
 

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Humanrob

Well-Known Member
You can kind of see what I have done. Each side can roll up plus if need be the top can roll also..Plus 2 fans... double 6mil. plastic for roof is a must.
Last year buds where huge! BUT! a lot friends lost bud to rot because of humidity. I was lucky, lost very little. Ventilation 100% better this time.
Why the double roof plastic? Are you using true greenhouse plastic, or the standard "clear" 6mil from someplace like Home Depot? I ask because I've read that a single layer of plastic can reduce the light by 20% (IIRC). One summer I grew the entire summer under plastic, the next summer I grew in the open and only put the plastic up mid-September when the first fall rains started. I've also read an article that talks about how diffuse light can be better for plants, obviously greenhouses work, I'm just interested in how different materials function.
 

Bugeye

Well-Known Member
Nice, but how you gonna get them on pallets now? Maybe not needed, I don't know. I think you'll fill up your space like a jungle, you got some big girls going for this time of year. Keep them off your ceiling, that will foul them in flower, wherever they touch it. Days are getting shorter now so get that hammer swinging! :bigjoint:
 

Houstini

Well-Known Member
Nice, but how you gonna get them on pallets now? Maybe not needed, I don't know. I think you'll fill up your space like a jungle, you got some big girls going for this time of year. Keep them off your ceiling, that will foul them in flower, wherever they touch it. Days are getting shorter now so get that hammer swinging! :bigjoint:
Oops, forgot to procure pallets. They're on membrane roofing so they'll slide in. They are big, the tallest will have to go in the center where the roof will be 10'. Been a busy couple of days here, will post pics this weekend after I get some more framing complete.
 

UncleBuck

Well-Known Member
there is literally no magic formula for protecting wooden posts, they will all inevitably rot when set into the ground.

just like there is no real way to protect outdoor buds in oregon from rotting and molding if that's how the weather goes.

just keep on top of what you find, remove it immediately, and do the best you can.
 
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