Storm Window Hotframe

Built this rig out of a couple of aluminum storm window frames. Holds temperatures in the 60's even in below zero weather, however it is dependent on electricity.




Started by setting up a jig the width of the raised bed to help build the frame.



Built a sub-surface solar powered heat exchanger from PVC and black poly tubing to keep the bed from freezing. A water fountain pump lifts water through coiled 1/2 inch black poly tubing into a gravity fed receiver. Alas the the drain coil could not keep up with the pump and had to be replaced with a straight length of tubing. To further help heat the bed an aquarium heater was added to the reservoir, kept soil in the 50's throughout the winter.



A small space heater controlled by a thermostat held temps in the 60's, was able to grow celery, lettuce, mustard greens, mint and onions.



A Univent Automatic Window Opener helps from overheating in the summer.

a reply to: Wreckclues
Nice work!

Tried a similar setup for my greenhouse to get through the winter with some plants, but in the end, electricity was too costly. I see you also have a lighting armature in use, how long are your days in deepest winter?

My own greenhouse is nearly 100% self sufficient. The wellpump is energized by the PV-panels that charge two car battery. It´s even enough to heat some pots in the winter so the citrus and oleanders have warm feet when it´s freezing cold.

I'm pretty sure you could take advantage of solar and wind power but that would be pretty expensive. LP anyone? How could this be cost effective? That's the big question.

a reply to: StoutBroux
If you have to buy the PV equipment, it´s not worth the cost. If you have parts of it laying around because it´s your reserve if SHTF with the PV-system, it´s worth it.

It´s never cost effective, if you look at buying stuff. The cost for the greenhouse, if it´s a decent stable one, you will never get that back with the money you safe with growing your own food. Except you do it big and manage to sell it.

But for home consumption, your main reward is your own food, own herbs and that you know what you eat. It´s not that urgent for me, I live rural and get most of my staples from the region.

Eggs, milk, beef, apples, potatoes, I buy them locally from trusted sources. Most herbs and vegetables are grown in the garden, the apples I get from my trees are juiced and bottled so I basically have my own apple juice and the rest of the neighborhood because I can´t collect the whole plantage myself. So I buy apples to eat them, although at the end of the year, I literally have a metric ton, but they all become juice.

a reply to: verschickter

how long are your days in deepest winter?

About 10 hours, used the grow light in the early days as an indicator of how often the heater came on, and now just use it as a light. My next step is to rig up a larger solar panel and a battery bank for the heaters, this is more a hobby than anything else so I'm not concerned with it "paying" for itself