When I bought my greenhouse several years ago, it was my chance to get as many extras as I thought I needed, within my budget. Only having a very small garden, I was limited to size, but still wanted a comfortable retreat in which to potter. The greenhouse has extra height with high eaves and an additional base, making the apex of the roof tall enough for me to need a stepladder to reach up to it. Air circulation was important and having just moved there, I was not familiar with the pros and cons of a small, shady garden, within the proximity of an even shadier, north-facing rear of the building. However, it was easier building all the requirements into the frame at the beginning, so I ordered four window auto vents and a louvre window. I think I may have overdone the air flow, but at least there was a choice.
It wasn’t long before I realised my overenthusiasm wasn’t really necessary and my four auto window vents were reduced to using two. The louvre window has never been used. On acquiring my neighbour’s old greenhouse, I realised how much of a nuisance having to manually open and close the window vent daily was, and decided to use one of the unused auto vents from my greenhouse on it. Having already fitted the four on my own greenhouse, I was confident it was an easy job, so what could go wrong? Quite a lot, it would seem!
Auto window vents work with a mineral wax filled piston, which expands when heated. That pushes the window up or down as it expands or contracts, according to the temperature in the greenhouse. A very simple control which is adjustable with how much you tighten the piston. The auto vents I have, are designed for the make of my greenhouse which is different from the small, inherited one. Thankfully it’s only a slight difference in the frame, and it can still be used.
My confidence in removing the hinge from one greenhouse to fix onto the other was short-lived. The spring on the hinge was so powerful, I could not keep it open whilst trying to screw the bottom plate to the window frame. I dropped the screws, several times – and the clamp which holds the hinge to the frame, and each time, if I couldn’t see where I dropped them, the plants were removed to enable me to locate each missing item. I evicted slugs, snails and a lot of surprised, sleepy spiders and still one screw and one clamp was missing.
I then realised where I was going wrong, so first took the piston and put it in the fridge. The next morning, I was back, still searching for the missing parts, then realised the missing clamp was already in place between glass and frame of the window and the missing screw was already holding the other clamp to the hinge! The piston was much more manoeuvrable when cold, so within a few minutes, the job was done.
I would never have a greenhouse without an auto vent, but for the time being, I continue to visit the greenhouse first thing in the morning and later at night, just to make sure the auto vent is still working!