500 Year Vision

Take pleasure from walking lightly on this Earth

Using the outside of a lined chimney as an air heat exchange system


After a drawn out autumn, which in fact lasted till the day after Christmas, winter has come. I sit in my kitchen watching the snow drift past the window. It is mounting outside, the sky is white, the trees are white. All of a sudden, it was minus fifteen when we woke up in the morning, burning much of what was left in the garden, then the snow came and buried the rest. I have teepees constructed with apple tree cuttings and plastic – just two sided, but enough so that I could harvest quite a lot before the serious snow.

Our heating this year is via a boiler in the cellar which we feed wood pellets. On every radiator around the house is a digital valve which controls the temperature specifically for the function of the room. The office isn’t heated at the weekend, the bedrooms aren’t heated during the day. We have wood-burning stoves in the kitchen and guest bedroom which we can light if we want things to be a bit warmer. If you have a fire, it needs to draw air from the room in order to burn. Where is this air coming from?  Every time the doors are opened cold air will rush in. It’ll seep in through any gaps around windows or under doors.

One idea I had was to put pipes underground to pre-warm air before it reaches the house. It would have been easy to put an extra pipe in the trench between the house and the well, for example, if I’d thought of it before we filled in the trench, that is, however, the metal-lined chimney gives me a much better opportunity.

When the boiler system was installed we had the chimney lined with a very expensive metal tube which was drilled into place.  As a round peg in a square hole, there is still quite a lot of volume in the old chimney which is outside of the lining. Our thermal flashlight had indicated xanax bars here that the chimney was warm through the house above the heating system and the metal pipe was hot to the touch even in the attic (where there is an inspection hatch). I now have an extractor fan between the chimney and the laundry room with a thermostatic plug (BY-LOX_15A) which will switch on when the sensor detects temperatures above 18 degrees c.  The extractor fan draws warm air from beside the metal chimney into the laundry room when the chimney is warmer than the laundry room. Eventually this air will be pulled into our unheated hallways  – currently hovering around 10 degrees c.  So – we’ll experiment and measure results.

One concern could be contamination of the air supply with carbon monoxide from fumes leaving the chimney. We have a carbon monoxide detector to test for that – experiment and measure…


posted under Elements

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