I grow orchids in a makeshift gh, and control temps pretty well with an air chiller I added this spring. Its efficiency depends upon the ambient humidity, but allows me to grow intermediate orchids along the wall next to the intake. When humidity is near 20% I can reduce temps about 7-8F in that microclimate below outside ambient, such than when it is 90-92F outside I can have temps in the low 80s next to the intake. The rest of the gh temps are lower as well. When humidity is higher, the benefit is less. I have plans to make the chiller larger by two-thirds, as it is not quite large enough yet. The chiller is an exterior structure, with both an intake and exhaust fan operating it. Inside are fogging heads, and chambers separated by plastic furnace filters. Initial cost was ~$75, and when I add on, maybe another $75 or so. With orchids and other sensitive tropicals, using an interior misting system to lower temperatures is not always a good idea. (Unless it's time to water.) You could end up making plants wetter than they'd like, or have residual water overnight in crowns/leaf axils. Excessive water also invites things like botrytis, and shortens the longevity of blooms. Under-bench misting is good, but requires a separate system and valve/timer. I also use some shade cloth, but in the interior depending upon the needs of various orchid types. So, my use of it is only to control light, not temperature. -Bruce C.

"mild pressure washer to clean the walls or if it's better to maybe use a hose and a mop" The answer, I believe, is both; each in their place. Treat the polycarb on your GH as you would the finish on an auto: get it thoughly wet with a mild pressure spray first, then soft mop with cleaner, as to not grind fine particulates into the finish, and as the "uck" you refer to is likely residue from jet fuel, it could do real damage to the polycarb, so regular washing will be one of those "must dos" for you. However, when it requires a cleansing agent in addition to water, you must be very careful and of all the products that will work well, are safe on UV treated polycarb, cheap and available anywhere, few will beat Joy in hot water. As subjected to airbourne pollutants as your GH will be, it might also be a good investment for you to get some acrylic polish, to give the polycarb extra protection, and for that; I would recommend a product called Brillianize. It will actually repel a lot of the "ugk" and allow you to quick rinse it off before it has a chance to damage the polycarb. As for a mop; just be careful to use one with no sharp edges or projections that could scratch the thin UV coating on the polycarb. Old fashoned, flat headed, cotton dust mops work well for the purpose. I can't speak to how well, or long a HFGH will hold up as opposed to any other made of the same materials, but would venture to guess that a good application of aluminum polish on the structural members, before the GH is assembled, wouldn't hurt. If I had known of what a great benefit the Brillianize would be for the polycarb before we assembled my own GH, I would have laid out the panels on a firm, flat surface and treated them then, instead of needing to climb ladders, after-the-fact.

Glass is a great material, and is a good choice for longevity, clarity, versatility and structural strength. If you are building something "in town" or you want to attach to the house and blend in well from an architectural standpoint, it seems that glass is without a doubt the best choice. For my particular situation, glass isn't the best choice. I'm using single layer woven poly on my three greenhouse structures for several reasons: -Inconsistent framing on a salvaged building turned into a greenhouse is easy to secure with a poly cover. -Curved surfaces on one greenhouse won't accept glass. -Poly isn't heavy nor dangerous to install by myself. -It isn't prone to failure with hail. We have more hail here in Cheyenne than anywhere else in the country. Cars get dented, roofs get damaged and windows get broken. -A single piece covers an entire building without any need to frame each pane. -Much lower initial install price, and about the same cost over the life of the buildings, even if I consider the cost of replacing it several times. -The cost of the entire structure and poly glazing is about what glass alone would cost. We have one more greenhouse to build and it will be a wood structure attached to the barn. I'm thinking of using poly carbonate either in rigid sheets or rolls. Clair Here is a link that might be useful: My homemade greenhouses

Thanks for the info on the bubble wrap. I intend to attach with clamps from the cheapest I can find (my husband loves clamps and has volunteered to help with this). My problem has also been to reduces heat in the summer. Will this help at all or should I use something else. For this winter, I want the bubble wrap. For next summer, I just want ideas since the water is supplied from a well and also feeds my parents home. I did not use the greenhouse this summer due to water risks from the draught. Anyone got any ideas? I already have exhaust fan, roof vent and back wall vent and am running three fans. Purchased a portable swamp cooler but early on it couldn't handle the heat so I need something else to help.