Darin Anderson

I've reached out to CRMPI to do a review of the designs, hopefully a ounce of prevention is worth a pound of cure

Thanks for all the inputs from everyone, comments are always appreciated!

Thanks for the thoughts and inputs, I've adjusted the design to try to allow better ventilation, light coverage, and light diffusion. Again, inputs are welcome!

Adam Klaus wrote:The ceiling chimney will not dump hot air fast enough, IMHO. It is very easy to fry your plants in a greenhouse. Cross ventilation from the two ends of the greenhouse is a key design feature that is almost always used.

By adjusting the pitch to a 5in12 I was able to increase the chimney window height to 2' tall and given this extends across the 35' width this seems to be a decent amount of airflow potential? Also increased the chimney size to 3' to further increase that airflow.

Adam Klaus wrote:Problem is in summertime, hence the need for tons of cross ventilation.

While difficult to tell, there will be awning windows in the lower vertical window wall to allow air inflow. There will be some similar ones on the east side wall. The west wall is connected to the house and for use in fall / winter when needed.

Adam Klaus wrote:Your back bed wont get enough light.

With the slightly lower pitch I've been able to extend the direct sunlight potential into the back bed. This combined with the opaque glazing to better diffuse the light across the space will hopefully address this?

Adam Klaus wrote:Finding ways to minimize the temperature differential from day to night, while allowing ample light levels, is the challenge of greenhouse design. Strategies like CRMPI's climate battery are genius for that.

The large concrete thermal mass, the 12k gallons of water, and the large adjoining open garage air space was intended to smooth temperature fluctuations - were you referring to something else or you don't believe that in conjunction with the ventilation is sufficient?

Adam Klaus wrote: I would reccomend having a polycarbonate south wall and ceiling. Have the north wall shared with your house.

I did update the slanted ceiling to twin wall opaque polycarbonate, but was planning to leave the lower vertical wall glass for the longer lifespan even though the higher cost ( comparison here) - I also need the vertical glazing to be able to have awning style windows for ventilation. Good plan? As for the north wall, that simply extends into the garage (see picture in initial post) to attempt to leverage the thermal mass in concrete, water and air.

Excellent thoughts and ideas, thanks again to everyone for their thoughts.

After reading more on the sites folks have linked, I've done a substantial rework to the design as seen in the picture below. I'd like again for folks comments on if this will function decently:


Special notes
- More of a typical 'slant' greenhouse integrated into the garage space. I 'superimposed' the greenhouse outline over the house framing that will be adjoining it for better understanding of the intended integration
- Blue indicates glazing, green is external framing areas, pink is internal framing areas
- Raised beds are 3' in height for ease of access and wider options for planting (root profiles)
- Glazing slant pitch is recommended 45 degrees for summer sun deflection, snow shedding, and better moisture deflection (less condensate on higher pitch)
- Upper area is essentially a 'chimney' leading to automatic windows triggered based on humidity or temperature
- Solar coverage on the growing beds will be 100% in winter, decreasing down to roughly 60% direct sun in the height of summer
- Minimizes the amount of glazing required which then increases the insulation levels (attic space is R60)
- Rolling insulated shutters on all glazing for insulation and security

To address some questions / comments on my application:
1) Intention is year round growing potential, I need to be able to have a reasonably productive garden year round
2) I understand there is overkill in this design (like the rolling shutters). But this house will be my residence for the next 4-5 decades and it's worth the additional consideration

Chris Jose wrote: Simply put, at least 30-50% of your grow space needs to get summer sun and obviously that would mean it gets good mid season and winter sun also. You could get away with less, but remember, without direct sun, most plants will not thrive.

That's great info. So if my 'grow space' as allocated in the design is 16'X35' then I would need between 168 to 280 sq ft of glazing overhead to meet that 30-50% number, sound right?

Chris Jose wrote:Have you looked at growing micro-greens?

Never had, and that sounds like a great option. I'll research into that further, thanks!

And in an original design with overhead windows I was trying to figure out how better to insulate them in winter months. The retractable insulated shades on the vertical walls works great, but with the snow I'm expecting they won't do for the roof I'm afraid (at least externally). I'll have to explore if that can be done internally under the glazing for the overhead sections, or maybe just a manual insulated panel for the winter months.

Great tips, thanks!

I was hoping against that, but had a feeling that might be the case....

If that's true my options are?
1) Put in some overhead windows (per normal)
2) Maintain the ceiling integrity and reflect light in with tiltable mirrors outside the window

I'll check out the site you mentioned, was not aware of that - thanks for the tip!

I'm attempting to build a greenhouse that I can grow out of year round in Colorado at 9k feet - and 'passively' (no mechanical heating assistance). I'd like folks ideas on my design below, specifically the following question:

- Will the window locations / sizes allow enough direct / indirect sunlight throughout the course of the year to allow the plants to grow?

Examples of current direct sunlight coming into the room in Winter, Spring/Fall, and Summer (see pictures)





Background:

Home location: Near Cotopaxi, CO @ 9k feet, south orientation, no shading

Greenhouse is a 16'L x 10'H x 35'W area within an oversized garage 50'L x 10'H x 35'W and 3' awning overhang (see picture below).

Heavily insulated / airsealed
- Triple glaze glass
- Insulated shutters that close at sunset and open at sunrise
- R60 in the attic, R30 walls, R20 under slab

High thermal mass
- Full concrete slab
- 3 concrete cisterns holding a total of 12k gallons of water