Developing Auxiliary Systems for Off-Grid Living: Part I – Solar Air Heating
Drew has been working since Christmas break and has built three solar air heaters from scratch; iterating some design tweaks along the way. The results are in!
Often, we will have a fire in the morning and then let it go out while we are at work. Normally the house would be around 15-17’C when we get home. I sometimes work from home and have seen the thermostat go as high as 23-25’C around lunch time with the only heating coming from the solar air heaters. The temps coming directly out of the air heater are running 45-50'C. Have a look at the exterior and interior set-up here.
The bathroom gets warm enough that I opt to leave the door open when taking a bath or shower just so that I don't over heat! Years ago when there were still baseboard heaters in there, you wanted to turn the heat up and shut the door 15 minutes before your shower just to be comfortable. You can see a bit more on the construction here.
Since we are off-grid it is a bit harder to measure the efficiency of heating this way (figuring out wood usage as opposed to looking at a power bill), but we are very happy to live in a much more comfortable house. There are three fans that help with air circulation, but they draw very minimally from our power supply. On a sunny day we usually want to use more energy anyway since we will often produce more than the batteries can hold.
Also, there are the solar “blinds”. This is aluminium sheeting that we put over the windows on a sunny day. To make these you just cut to size, paint black on one side and make a little frame to hold it against the window. The temp. gun has consistently given a reading of 45’C radiating from behind the blinds and into the room on a sunny day.
The best thing is that the three heaters cost just over $1,000 to fabricate at home and Drew was able to install them himself. The blinds are very cheap and could be made by anyone with a few hand tools. This would be a wonderful help for people who are stuck using base board heating and can’t afford to transition into better heat sources yet.
After an epic tri-province/ 17 hour Kijiji excursion last weekend, Drew has gotten some second hand supplies to get started on building a solar hot water system. These will need some MacGyvering and will take awhile to get ready. I will report on Part Deux in the coming months.
On March 16th there will be an eco-building and home retrofitting conference in Fredericton (University of New Brunswick campus). If you are in town, come by! Drew will be on the home owner panels answering questions. On June 1st the Conservation Council of NB will be organizing a second year of Eco-Homes tours in Greater Fredericton, Greater Saint John, and St. Andrews areas. There will be newsletter updates to come. If you want to share you home building or retro-fit story, you can email firstname.lastname@example.org.
Cheers and Happy Homesteading,