Venting the Greenhouse

Cross Ventilation Benefits
Spring in the Pacific Northwest has been cool and dry this year. Memorial Day weekend generally is marked by wet, cold weather. The past two weekends we have climbed into the high 80’s. The greenhouse is baking inside due to the recent increase in temperature.

Base vents were installed when the weather was much cooler. Although they have assisted in keeping the temperature stable – without cross ventilation lifting and releasing hot air building up inside – the thermometer registered over 100 degrees.  We installed the Easy Flow Louver to the upper back greenhouse wall to expel hot air and add fresh air inside.

Materials and Time Required
Total project materials cost averaged $140 and two hours to complete with two people.

Note: These steps are an overview only and should not be used specifically as step-by-step instructions. Each project will have its own unique site challenges.

Prep Work

Step 1.  Clear inside of greenhouse to allow for maximum working space.
Step 2.  Prior to beginning project, charge all cordless tools.
Step 3.  Pick a clear, cool and dry day to work.

A Jigsaw Puzzle
Since the aluminum frame is a non-standard greenhouse frame, it creates challenges at every corner. When I initially measured the opening it had enough room to accommodate a 24” x 12” vent described in the catalog. The 24” x 12” dimension detailed only the vent opening. Including the outside flange, the vent unit was approximately 26” x 15”.

A one hour project quickly progressed longer trying to make the unit fit into limited space. In hindsight, it might have been easier to remove the Solexx® panel, attach the vent to the metal frame and replace the greenhouse panel. But there would have been a 1/8” gap. Instead, we decided to remove part of the louver frame and custom fit the vent into the existing space.

Cutting Corners
In order to make the vent fit, we decided to cut the corners off the top.
• Screw 24 pt blade into the jigsaw tool facing out. 
• Check the depth of the frame when sitting flush on the bench.
• Place scrap wood under frame to lift the vent. It will need to be tall enough to allow the jigsaw blade to clear the bench.
• Secure louver frame snuggly with quick grip clamps to stabilize the vent on workmate table.
• Mark corners using sharpie marker and straight edge or metal angle.
• It is important to keep checking the fit to make sure you only cut what is needed to fit the wall space.
• We had to shave off part of the bottom frame as well, leaving just enough room for the louver opener holes.

Solar Powered Workhorse
The louver opener does not require batteries or electricity. Adding the opener allows the greenhouse to stay heated or cooled automatically.
• Before installing the louver into the greenhouse wall, assemble the louver opener and attach to louver frame.
• The assembly instructions provided for the opener are clear and concise. Assembly took approximately one half hour.
• Important Tip: The cylinder rod is filled with gas. The rod expands and contracts with rising and falling temperatures. On a hot day, the rod expanded making it impossible to fit into the black casing. 
• We placed the rod in the freezer for one to two minutes while enjoying a popsicle break. Once cold, the rod fit snugly into the casing.
• Using a socket wrench, attach the opener to the vent frame.
 
Installation Tips
If your greenhouse has adequate space to accommodate the frame, the below listed instructions will suffice to install the louver vent and solar opener.  Total installation time should take about one hour total.

Note: I do not recommend installing the vent when the temperature is warm, sunny and a seemingly perfect golfing day. Your partner might be less than enthusiastic assisting with the installation.

• Similar to the base vent installation instructions, create a template using cardboard to outline the vent opening.
• Trace the outline onto the Solexx panel and cut using a box or utility knife.
• Attach the vent into the greenhouse frame and Solexx panel using a power drill and ¾” self drilling screws. 

Photos taken by Dawn Hummel.