Redhouse December Update

The last few months have been trials, full of learnings and many successes.  This is really only my second tomato growing experience and first experience with a greenhouse.  First  let’s look at the successes.


I’ve harvested several pounds of tomatoes so far.  There’s several more pounds to harvest.   On addition to the tomatoes, I’ve harvested lots of parsley as well.

The greenhouse is fully automated.  The irrigation, the lights, the solar, heater the blower… just about every electronic component is controlled by my custom automation software.  I’ve been tweaking the rules for months and its working really well.


Humidity sufficated many flowers in Sept and October.  They developed mold which prevented fruiting.  Adding a dehumidifier to the system solved that and fruit started to set in November.

Electricity has been my latest trial.  It started getting below freezing so I added an electric heater.  The load from the heater started popping my 20A breaker.  On night it popped and temperatures dropped to -2C air and 9C soil.  This caused serious damage to more than half of the 10 tomato plants.  The planta dropped flowers and aome of the youngest fruits.  To solve the issue temporarily I put the heater on a separate breaker with a long extension cord.

Between the humidity and the cold I probably lost 2 months of future harvests.  After December, I may not see another harvest until March.


Avoid higher than 80% humidity.  85% is a critical threshold and mold will start to take over.

Don’t share electric breakers.  I did not foresee the need for a heater.  Even so, future proof yourself by putting your greenhouse on an independent breaker or two.


The door leaks heat.  It needs to be rebuilt.  When I start, it needs to get done *fast* because I can’t leave it unfinished at night.

CO2 generator/water heater.  I found a water cooled CO2 generator.  This is perfect for a geothermal water system because it heats the water AND produces CO2.  I may be able to eliminate the electric heater if this thing works.

Measure electrical cost.  I plan on adding a current sensor to the new breaker.  I’ll be able to see what my electrical costs are and use that in my automation software.  I’ll be able to create “power saving” rules when costs exceed expected production.  The current sensor has been installed, now I need to get it tied into the system.

I have almost 600 Watts of grow lights that still need to be built and installed.  200 watts on bed A (the tomato bed) and 360 watts for bed B (strawberries, onions, garlic, herbs).  This will help with growth especially with the onions and garlic which don’t get any direct light because of how low the sun is in the horizon and how high my fence is.  It will also help produce heat at night as a fallback if the geothermal system or water heater can’t keep up.


It’s been a rough few months, but things are literally looking up as new growth is being observed in many of the damaged plants.  After the door is rebuilt, I believe the heat and even the cooling and humidity problems will be solved for good.  The new wall where the door will go will have vents and fans for intake and exhaust.  I’m excited about the improvements in progress and seeing some real results.

Happy new year everyone and happy 2016 harvesting!

2 thoughts on “Redhouse December Update”

  1. on the humidity and mold issue, fans for air circulation solved mine. I put in the side circulating fans and ceiling fans to keep the air moving and have eliminated all my mold issues in both my tomato greenhouse and lettuce greenhouse. Did not see those mentioned

    1. Did/do you circulate air in and out of the greenhouse? I added a fan in late summer, but it wasn’t enough and there was no air exchange with the outside at night. When I rebuild the door, I plan on adding exhaust and intake fans.

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