Greenhouse Roof Angle

You ask about solexx glazing.

Greenhouse roof angle. While the logic behind this rule is sound it is a dramatic oversimplification that can lead to costly and unnecessary decisions to build very steeply angled roofs. Specialization is for insects. Same approximate angles as your 90 degree calculation model. The best angle for greenhouse glazing in the roof is not as clear cut as some solar greenhouse designers make it sound.

Solar greenhouse designers often cite a rule of thumb along the lines of. To find the best angle for a greenhouse roof take your latitude and add 20 degrees. If you design your internal structure according to local codes however you will not have any difficulties. I m not sure what the optimum for greenhouses is although following your stated numbers of 44 degrees latitude with the 20 plus or minus values gives you 64 degrees for winter and 24 degrees for summer.

Framing and glazing materials. To give your plants the optimum solar radiation and the least reflection year round you need to angle your roof perpendicular to the sun on the winter solstice. The two most common framing materials are wood and metal. This will shed snow under most conditions but with twin wall coverings it is not always the case.

Related to the roof slope is the freeboard the space between the lowest point of the roof and the ground. In areas with heavy snow at least 3 or 4 feet is good to have so that snow won t pile back up onto the greenhouse roof or obstruct any vents.