As the month commenced, the outdoor temperature rapidly dropped. The coop temperature initially followed suit, but then became remarkably stable. Although changes in the outdoor air temperature are clearly represented in the coop temperature, the chickens have enjoyed a range of 35-45F. Though hardly luxurious, such a temperature range is easily tolerable by the birds.
For the first half of the month, the air was arriving in the coop at a predictable 55F. The air vent temperature dropped to a low of 40F at Christmas, before rising back to 55F. I strongly suspect the problem was a lack of airflow through the system.
Unbeknownst to me, the mesh guarding the intake pipe from squirrels had also begun to frost over, reducing the volume of air passing through the biomeiler. I have never before observed that phenomenon, because we have never had such an extended cold period during my biomeiler research trials.
When a duct fan is operating in a closed pipe, it merely circulates the air at the end of the pipe, giving the false appearance that air is still being provided at the exit point.
As the cold weather persisted, a more obvious and anticipated problem was developing simultaneously. The moisture in the used air collected in the exhaust vent pipe until the flow was significantly constricted. Because the coop is relatively tightly sealed, the lack of exhaust air required a reduction in the volume of fresh air entering.
It became an additional task at chore time to use a stick to scrape open the exhaust vent. Often, I would observe a stream of foggy air extending outwards for two feet, or so, before dissipating. Again, however, I was misled to believe there was still adequate airflow through the system.
Fortunately, I was attracted to the air intake vent by the impressive accumulation of snow balancing on the pipe. As I was evaluating the scene to find the best vantage point for a picture, I noticed the frost clinging to the mesh. A small amount of tapping dislodged the frost, clearing the air intake. Seeing no point in half measures, I used my heat gun to melt some frost out of the exhaust vent. After performing this maintenance, I was pleased to see the temperature of the air arriving in the coop return to the 55F level seen during the first half of the month.
The weather forecast calls for temperatures to rise to the -10s F in the next few days. After a month of cold weather, we will all appreciate a warm spell that allows us to travel without so much precaution and enjoy some of the outdoor activities that have been precluded for so long. Many people are looking forward to finally having the New Year’s fireworks. That event was postponed, for only the second time in its 37-year history, due to the -45F temperatures and the ice fog.
For my part, I will remember the past month with some degree of satisfaction because it provided indisputable proof that the biomeiler, in conditions as trying as any we are likely to encounter, has ability to maintain the coop temperature without supplemental heat. We completed the coldest month since 2005 with no need to turn on the electric heater!
Your results this winter will make marvelous facts to reveal in a future presentation somewhere!