Considering a hobby greenhouse in zone 6b. Help me!

[hhilgen2]

My orchid collection has steadily been increasing and my windows and lighting shelves are overflowing! I've been kicking around the idea of installing a small hobby greenhouse.

How expensive is the upkeep going to be on this? I'm considering a polycarbonate lean-to style. Probably going to pick the smallest kit I can find. It will be attached to the garage wall; would electric or propane heating be better? Any brand suggestions?

Help me, you guys!

[estación seca]

Polycarbonate comes in varying grades. Triple-wall provides the best insulation and will reduce your heating costs. Get the best insulation available.

[Fairorchids]

Once you take the step, do NOT buy the smallest kit available. You will outgrow it very quickly.

The heating & ventilation system will cost the same, whether you are working with 50, 80 or 120 sqft. Heating cost will vary of course.

Go min double wall. Then, in winter, insulate sides with a layer of plastic, or clear bubblewrap.

If you are a moderately handy as a carpenter, you can build it yourself from pressure treated lumber. That way you can insulate up to 30" height.

Over that height, add double wall sheathing on the outside, and a layer on plastic on the inside (giving you 3.1/2" sealed air space), and you will have as energy efficient a structure as is possible.

Keys are:
Add heating
Add ventilation
Add air circulation

[Ray]

I agree totally with Kim that buying small is mistaking big. However, the equipment needed for different sizes of structures does vary in cost, so you need to do your homework first. It is NOT, as many beginners think, just a matter of putting up a covered structure.

As to what to build or buy, there are SO many structure options, that you need to evaluate the entire project.

I built my greenhouse from a Turner Greenhouses kit, which they modified to fit a taller foundation. Hoop houses are probably the least expensive to erect, but aren't the prettiest things, so might become an issue in residential areas.

One of the most energy efficient designs I've seen was essentially a reinforced hole in the ground with a clear roof. Having the vast majority of the volume below ground saves a bundle on energy. A close alternative was similar in concept, but it was above ground, using well-insulated structural walls and a clear roof. Both of those are best for larger structures, as in smaller one, too much of the bench space is shadowed by the walls.

[hhilgen2]

Thank you all for your input. I've been doing a lot of research about the most efficient kits etc and had come up with a couple of contenders.

Are the Solexx models any good? I was considering one of these with reinforcing/insulating the northern (flat) wall and adding an insulating base around the bottom several feet of the structure. Also likely going to look into a heat sink via water retention:
Solexx Harvester Grenhouses

What about a solar heater? Would something like this do any good or just a waste of money?
https://secure.img1.wfrcdn.com/docre.../21/218879.pdf

[Ray]

Originally Posted by hhilgen2

Are the Solexx models any good? I was considering one of these with reinforcing/insulating the northern (flat) wall and adding an insulating base around the bottom several feet of the structure. Also likely going to look into a heat sink via water retention:
Solexx Harvester Grenhouses

I have looked at Solexx as a GH cover, but what concerns me is that the cover itself cuts down on the transmitted light. That might be great in more southern climes, but here in southeast PA, I have no sdhade all winter, so I wonder if the Solexx might end up being too opaque.

What about a solar heater? Would something like this do any good or just a waste of money?
https://secure.img1.wfrcdn.com/docre.../21/218879.pdf

How's that supposed to keep the structure warm at night or when it's not sunny for long periods of time?

[hhilgen2]

Originally Posted by Ray

How's that supposed to keep the structure warm at night or when it's not sunny for long periods of time?

Hahaha well, it certainly wouldn't do squat for those times, but I was hoping that it could cut down on my heating costs during daylight hours

[Subrosa]

If you want to maximize the potential of solar heating, thermal mass is the answer. A couple hundred gallons of water holds a lot of heat relative to a hobby sized greenhouse.

[Selmo]

All very good advice and ideas for starting a greenhouse build. Always build you house as big as your space and budget will allow. You will fill it up. Being that you are in zone 6b, you will probably need to heat your house during the winter months, at least at night. You should have a permanent heat source. I believe that natural gas is cheaper than propane, but if you don't have natural gas already, then propane is probably easier. You will alo need to cool your house in the warmer months. You will need, at least an exhaust fan and a vent to move air in and out of your house, and probably some form of shade cloth. You should run electric, for the fan and run water into the house. Do not depend on a hose from your home, be cause if it freezes you will have no water in your greenhouse and most likely water on your home. Remember what ever material you decide to build your house out of, this will be what protects your plants from the elements and will be their home for many year to come. Don't be cheap! Good luck and keep us informed of your progress

[hhilgen2]

Thank you so much for your input! Based on everyone's suggestions, I'm going to go bigger than I planned and am going to do a freestanding as opposed to a lean to.

I've done a lot of research and it seems like a Riga might be a good fit. They have the best R factor and they aren't opaque like a Solexx. We have a concrete slab on our property that is already wired for electricity since there used to be a garage there. I'm excited!