Chimneys Part 3 – Blowin’ In the Wind – Weather and Woodstoves.

This article deals with the question “Why does my stove work better on some days than others?”

You’ve probably noticed that sometimes you wave a match at your fire and it lights, but sometimes it seems like some magic force is working against you and your fire. And it is, but instead of ‘magic’, use the word ‘scientific’. There are things going on in and outside your house that will affect how your stove works.

I recommend reading the previous article on how your house affects the stove & chimney. Primed? Okay, here’s what else is going on.

As I mentioned previously the colder it is outside the harder your chimney will pull, generally. Though if your chimney is outside, unenclosed and uninsulated, colder weather will make that chimney cool down faster and can decrease your chimney’s draft. It’s always recommended to have the chimney inside the building envelope and if you can’t, build a nice cozy chase around the chimney. Also…

When we are experiencing a low pressure system (clouds, especially low cloud or an inversion), the sky is pushing down on the top of your chimney (score one for Chicken Little). When it’s sunny and bright there’s generally a high pressure system and it kind of pulls the smoke out of the chimney.

Wind can be a factor too. If, like me, you live on a mountain side on the lake you will notice the wind blows up during the day and down at night. Most people have seen the smoke from their chimney going down instead of up. That wind is blowing down on your chimney as well as from it – more downward force.

If you live in a flat open space (like the Creston Valley) wind can whip past the chimney, pulling smoke out extra hard (venturi effect) or whip past the peak of your roof and push down on the chimney. Wind blowing past your house can wreak havoc on fresh air intakes as well if they are on the wrong wall as well.

These things, alone or in concert, can mean your stove and chimney won’t draw as well, and it’s more likely smoke will spill into the room when you go to load it, or your fire won’t start as easily.

You can see it’s difficult to assess exactly what effect the weather is having to your set up, and it’s one of the problems in assessing the reason someone’s chimney isn’t working very well. All you can do, really is keep an eye on the weather and try to adjust how you’re using your wood stove accordingly.

For example, since you’ll have weaker draft in your chimney come spring and fall try having smaller but stronger fires. One tip is to put the firewood in so the ends are side-to-side instead of front-to-back. Then less wood will be exposed to air and flames at once so there will be less fire at one time to keep you from overheating your house.

And of course save your ‘better’ firewood for dead of winter and longer overnight burns, and use the less quality wood in the shoulder seasons. Birch, larch, fir and fruit tree wood are denser and have the most BTUs per cubic inch. They’ll burn longer and give more heat. Less dense wood (pine, hemlock or poplar) is better for when you can reload your stove more frequently or in the shoulder seasons when it’s warmer out.

For answers to your specific wood heat questions give me a call at Gray Creek Store – 250 227 9315.

By Dan Silakiewicz

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