Made popular by the Dutch, Venlo glass greenhouses are favored among commercial growers everywhere for their maximum light transmission and lower square foot costs that other glass houses. Roof vents are optional, coming in single or double vents, or the greenhouse can be sealed to create a completely closed growing.
The standard widths of the venlo glass structures are 20' 6", 24' 0", 30' 9", 36' 0" and 41' 0" wide. Custom widths are always available.
Posts to be set directly into the concrete pier or on post stubs in the concrete pier. The pier size will be determined by loading requirements determined by engineering.
A cast post top with an integral drip gutter support will bolt to the post and support the gutter saddle.
A galvanized steel gutter saddle will be at each post to splice the gutter and to bolt to the post top.
An aluminum extruded drip gutter is located under each gutter.
Cast aluminum downspout is used where downspouts are required. The hole in the gutter is predrilled for ease of installation of the downspout.
There are many options in the gutter extensions depending on the situation:
At each interior post there will be a bar joist which shall span across the structure at 12' 0" centers. This not only substantially strengthens the structure, it also provides simplified installation of additional equipment such as:
Aluminum extruded roof bars with a condensate clip to channel the condensate from the roof bar to the gutter and into the drip gutter is included. The roof bars allow for a "dry glazed" system with no putty or caulk in the glazing system.
Roof Glazing Options
Standard venting provides 15% roof ventilation capability with roof vents located on alternating slopes down length of each house. "Double" venting provides 30% roof ventilation capability with roof vents located on alternating slopes down length of each house, but twice as many. Continuous roof vents on one side of the slope or both sides of the slopes are available. The continuous vent provides 40% ventilation.
Rack & Pinion
A positive drive system shall be used with an easily understood and maintained rack and pinion drive system. Each roof vent zone to utilize rack and pinion operators (one per bay) connected to continuous push-pull vent shafting attached to individual aluminum lifting arm assemblies.
Each zone will be driven with two drive motors, with one drive motor to open the windward vents and another drive motor to open the leeward vents.
Each motor will have a reversing motor control box to wire the motor.
A computer control system with a weather station is required to install this type of house. This can be accomplished with either a simple weather station with a vent control or a more intricate environmental control system.