10' x 10' Shed and Greenhouse Design Radiant Floor Heat

First grow in a newly medical legal state Missouri. 6 plants flowering. Future possibly 12 or 18 plants as a caregiver.
After going back and forth between greenhouse or indoor grow set up I've decided to do both. The greenhouse will come later but the poured concrete floor will be done at the same concrete pour as the shed. I will be doing all the work myself along with some friends for help.
My ideas are not etched in stone and I am looking for advice on the design of this. Especially the grow room.

Here are my thoughts for design.
10' x 10' (OD) Grow room. 10' Walls

Poured concrete floor, Radiant floor heat (Pex pipe hooked up to a small water heater), Drain, Frost wall, all setting on 2" Foam Board and exterior of frost wall.
2" x 4" walls, fiberglass insulation with barrier, 1" blue board outside of walls under siding.
Mini Split Heat and A/C (Have one of these free, slightly used, big plus)
I can vent through the ceiling or the walls. It will have venting for both light hoods and fresh air. CO2 may be down the road. I will have a separate 3'6" (ID) entrance/ decontamination/ supply room. I plan on having a dehumidifier as we have humid summers.

Grow Thoughts:
Perpetual Grow
4' x 7' or 8' flowering room. Running HID (2) 600 or 1000 watt HPS. Not sure. Or I might switch it up between summers and winters. I'm not sure if I want to use a tent or build a separate room. I will probably start with a cheaper tent and see how it works out.
Veg , clone and mother's 2'6" or 3' x 6' area, no tent or separate room. I will stack this with clones on top and Vegging plants on the bottom.

Questions:
Radiant Floor. Is it worth it. I am only heating or cooling the grow room. I would like to keep the electrical cost down and figure this might help. Besides the water heater it only adds about $350
2nd door to greenhouse is adding space problems I have to be able to walk through. Makes sense to want this, wouldn't everybody want a door into the greenhouse. I can veg or flower outside certain times of the year. Any thoughts on layout would be appreciated.

Situation:
On about 20 acres. Rural area. The closest neighbor's house is 1/4 mile away. Will use carbon filters if I need to. There is an electric pole 60' from the shed. The electric company will put a meter there for $ 25 per month, $450 install cost. I can have as many amps as needed. House is 150' away I can have 60 amps. It would have to have a big wire. Not sure yet. Leaning towards a new meter. 6 plants to start with but I have a feeling a person or two may want me to be their caretaker. 12 or 18 plants.
The greenhouse is going to be later. I might be crazy but I'm sure as hell not rich.
I'm hoping to have this done by September or October. I do have limited time and this is a pay as I go. I should be able to knock the concrete out early spring. I have experienced help with this step.
I will be making a journal and posting pictures.

Any thoughts would really be appreciated because I really don't know what the hell I'm doing.

I used to live in MO. Moved out here to Colorado in 2012.

In the summer you are gonna want the AC in there if you intend to use that in the summer. In the winter you will likely need some heat. Some of the ductless mini splits will heat and cool. Good insulation is a must if you wanna save energy. Gonna likely need a dehumidifier, I always did in MO.

Id go ahead and put a 100 amp service on it, you never know what future will bring.

Floor heating in the greenhouse will be handy if you plan to run that in the winter with supplemental lighting.

Don't forget some security. Fence, dog, whatever.

Just a few thoughts I had about your setup. Tired here, damn dogs ate the satellite tv wire off the side of my house LoL. Gonna have to fix that tomorrow.

Another thought... You should put the greenhouse on the southern exposure so it gets more light.

Howdy brother! Exciting times in Missouri, I'm in the middle of the state with rural property too.

If I were you I'd bump the shed frame to 2 x 6 and keep the 1" insulation board as your sheathing. I reckon for a roughly 10' x10' structure the initial cost would add about $350 but the payback down the road would be worth it with more insulation. Also depending on your framing plan you might get away with 24" stud spacing. Make sure you tape the insulation boards and caulk any other seams...get it as tight as possible. I'd stay away from spray foam insulation, I don't trust the off gassing and have a feeling this will eventually come full circle and bite folks in the ass with environmental hazards.

For the radiant heat I'd use a Kerdi product that you could concentrate only where you really want it to keep roots nice and warm and rely on the mini split for the bulk of your heating/cooling.

Since you've got the land and privacy I'd also concentrate on a large outdoor summer season for the bulk of your growing. Can start seedlings early indoors and move them out when the temp/light cycle is right. I've routinely pulled 12-24 oz plants out of 20 gallon pots this way under not ideal wooded locations...if I could have them out in the open with full sun and larger pots or in ground I'm confident 3 pounders and up are feasible.


Good luck! Have fun!

I think I will be adding the electric meter and yes, I probably will use a 100 amp panel. I wont need that much but I will have enough for anything I might want to add. I hope I never have to worry about security. We are pretty secluded and have good neighbors. I do have a 110 pound shepard that really just doesn't like strangers. He is socialized and go's a lot of places with me. But he is territorial and will let a stranger know real quick that you need his permission to be there.
I do have the building oriented so the greenhouse will be south facing. Yes, I do want the option to grow in a greenhouse and take advantage of the natural sunlight. We wont be legal to grow until August 3rd. It kinda messes up the greenhouse grow for this year. That is one of the reasons to complete the grow shed first and add the greenhouse next year. I'm really wanting a door from the grow shed into the greenhouse. It puts a strain on the floor plan. I might have to make it a foot or two wider. If I keep everything under 300 sq. ft. there isn't a permit required.

I never thought about two foot spacing and going with 2x6 instead of 2x4. I am concerned with electrical cost and this may be something I do. Want to keep the heat and AC in. My concern with the radiant floor is that I do it and it cost me more than the mini split to heat rendering it useless. I also kmow that heat radiating from the floor comfortable and keeps the heat near the roots.

You may wanna take a peek at my indoor grow (linked in my signature), you might get a few ideas for your setup. Make the most of your count and grow em big! One can get some pretty staggering yields indoors with big plants if you have side lighting. I run 6 big plants in an area thats 15 x 22 feet. I can pull around 20 pounds out of that 6 count. I have a 24 count so I have two of those rooms flowering on a flip and a veg room that has plants vegging for the next round. Like this I can get a harvest about every 90 days with a 70 days flowering time.

If you can go with 10 foot ceilings you will be able to grow bigger plants without having to worry about the lights being too close.

If you have access to propane or natural gas you should pipe some in for CO2 generators. Boost those yields. I had a setup in the country in MO, the power would go out in an ice storm and we would be out for a while, longest was 10 days. So I put a propane backup generator in, man that paid for itself by saving a run. Something to consider for future expansion.

Just spit balling some thoughts.

Renfro said:

You may wanna take a peek at my indoor grow (linked in my signature), you might get a few ideas for your setup. Make the most of your count and grow em big! One can get some pretty staggering yields indoors with big plants if you have side lighting. I run 6 big plants in an area thats 15 x 22 feet. I can pull around 20 pounds out of that 6 count. I have a 24 count so I have two of those rooms flowering on a flip and a veg room that has plants vegging for the next round. Like this I can get a harvest about every 90 days with a 70 days flowering time.

If you can go with 10 foot ceilings you will be able to grow bigger plants without having to worry about the lights being too close.

If you have access to propane or natural gas you should pipe some in for CO2 generators. Boost those yields. I had a setup in the country in MO, the power would go out in an ice storm and we would be out for a while, longest was 10 days. So I put a propane backup generator in, man that paid for itself by saving a run. Something to consider for future expansion.

Just spit balling some thoughts.

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Thank You.
I will check out your grow. I really don't know what kind of yields I will get. Growing is new to me. I have had a buddy years ago with an indoor grow, But know I can get my feet wet. I will probably just use one light and a 4x4 area the first grow or two. And yes co2 is an option in the future. I think I need to get everything dialed in. I should be set up fine for a sealed grow room.
I worry about the electric going out. It doesn't happen as much as it used to, but usually once a year or so it does. I'm sure the first time it ruins a harvest I'll be taking your advice on the generator.

Renfro said:

You may wanna take a peek at my indoor grow (linked in my signature), you might get a few ideas for your setup. Make the most of your count and grow em big! One can get some pretty staggering yields indoors with big plants if you have side lighting. I run 6 big plants in an area thats 15 x 22 feet. I can pull around 20 pounds out of that 6 count. I have a 24 count so I have two of those rooms flowering on a flip and a veg room that has plants vegging for the next round. Like this I can get a harvest about every 90 days with a 70 days flowering time.

If you can go with 10 foot ceilings you will be able to grow bigger plants without having to worry about the lights being too close.

If you have access to propane or natural gas you should pipe some in for CO2 generators. Boost those yields. I had a setup in the country in MO, the power would go out in an ice storm and we would be out for a while, longest was 10 days. So I put a propane backup generator in, man that paid for itself by saving a run. Something to consider for future expansion.

Just spit balling some thoughts.

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Holy cow that grow is awesome Renfro. Maybe sometime in the near future I can hone my skills to do that.

Mogro said:

Holy cow that grow is awesome Renfro. Maybe sometime in the near future I can hone my skills to do that.

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You will get there. There are a LOT more resources now than when I started 30 years ago. All we had was hightimes magazine lol.

Just build your space so that it can be upgraded easily. Plan for the future and you wont regret it. One thing I wish I could have afforded when I set this up was the epoxy floor coatings. Easy to clean!

Just a thought... Buy a prefab to your framing specs and do the rest of the work yourself. I went and walked a lot full of prefabs and most of the decent ones were 16 inches on center. I found one half off that was a repo and was like brand new. 12x16 for 3k was hard to beat delivered and set up/leveled on blocks for free.

SwiSHa85 said:

Just a thought... Buy a prefab to your framing specs and do the rest of the work yourself. I went and walked a lot full of prefabs and most of the decent ones were 16 inches on center. I found one half off that was a repo and was like brand new. 12x16 for 3k was hard to beat delivered and set up/leveled on blocks for free.

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I have thought about that. If I install radiant floor heat in a concrete slab I will just build one and far superior insulation. The radiant floor heat is PEX tubing tied to the rebar in the concrete in loops. That is hooked to a small hot water heater with a circulation pump. You do have to pour the concrete on insulation board. If not the cold ground soaks all the heat out.

Mogro said:

I never thought about two foot spacing and going with 2x6 instead of 2x4. I am concerned with electrical cost and this may be something I do. Want to keep the heat and AC in. My concern with the radiant floor is that I do it and it cost me more than the mini split to heat rendering it useless. I also kmow that heat radiating from the floor comfortable and keeps the heat near the roots.

Click to expand...

Howdy brother!

Yeah, 2 x 6 framing on 24" centers would be the route I'd go for maximum efficiency. It'll cut down on thermal bridging and provides about 50% more insulation cavity over 2 x 4. If I were you I'd ditch the hydronic heating and just focus on getting the envelope as tight as possible. I'd still insulate the slab, it'll give some marginal R value but more importantly in my mind it will help in maintaining desirable humidity levels.

Oh yeah...Renfro's grow is the shit!

Have a great day.

carlsbarn said:

Howdy brother!

Yeah, 2 x 6 framing on 24" centers would be the route I'd go for maximum efficiency. It'll cut down on thermal bridging and provides about 50% more insulation cavity over 2 x 4. If I were you I'd ditch the hydronic heating and just focus on getting the envelope as tight as possible. I'd still insulate the slab, it'll give some marginal R value but more importantly in my mind it will help in maintaining desirable humidity levels.

Oh yeah...Renfro's grow is the shit!

Have a great day.

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This is the information I was looking for. It seems like you know a thing or two about heating and cooling. Why would you scrap the hydronic heating. Would the mini split be more efficient. I am looking for the most economical way to heat this. I will pour the slab on foam board regardless.