”Don’t think the garden loses it’s ecstasy in the winter. It’s quiet, but the roots are down there riotous.” – Rumi
This is the season, the time of year energy just flows back into our little Alaskan world. There are feet of snow on the ground, but the greenhouse is getting up in the 70-80’s during nice days. This is the time of year we plan our garden and try to design any building projects for the summer season. This is also the time of year for the best reflection and evaluation from the last year happens, as we need this evaluation to design improvements for the future. The design cycle never stops for this house.
Our little solar greenhouse is on its third winter, and some changes are in order. The concept here was to have a high level of insulation (for a greenhouse), with minimal glazing to the south, to integrate chickens, and to use an earth tube as a temperature and humidity control technique through out the year. The greenhouse has worked quite well over the last couple years, but here is where we can improve.
Chicken integration is still what we want, but here are a couple of the challenges/opportunities. Dust – after a couple months of growing inactivity there is roughly a 1/4″ of dust on every surface of the greenhouse from chickens being chickens. To fix this we have just installed remay (floating row cover) to the walls of the interior portion of the coop. This should filter out any dust as air transfers between the growing side and the coop and make life easier for the plants. Air exchange – In the past we have kept 6 chix over the winter in about 20sf with access to outside. We’ve had to leave the chicken door open to the coop to provide enough air exchange to mitigate ammonia build up over the course of winter. This also means we loose the majority of the heat we’ve stored over the summer. In order to ease this we will only keep 4 chix or less in the future, and will add cloth flaps to the chicken door to reduce air leakage.
The combination of an earth tube and automatic window openers has worked terrific for controlling temperature in the greenhouse. The downside has been these systems, and the chickens, have acted as a dehumidifier during the growing season. We control the earth tube fan circulation by two thermostats, one for cooling and one for heating. This summer I will narrow the window of fan operation from virtually all the time to only when heat storage or heating is needed. We will also increase the number of plants in the greenhouse, and water more deeply and often. Lastly we will adjust the automatic window openers to open at a slightly lower temperature so the air in the greenhouse does not absorb as much water before it leaves.
Although we have not reached out goal of creating a greenhouse which does not freeze in winter with out the addition of heat, we have an amazing space for growing and chicken raising that only freezes for about 2.5 months. With some redesign this season we hope to make the space even more productive.