The February Experiment: Heating with Wood Fire

After writing my last post, and happily confirming that our house had exceeded our expectations for energy use for 2016, I’d made the comment: Based on the predicted numbers, the heating energy likely accounts for about 50% of our overall energy use. Makes me wonder too how much better we could do if we burned wood a bit more often?”

I’d written that without thinking about what that would mean too much. But after re-reading my post I got thinking, ‘Hmm… what if we did burn wood more?’

We tended to keep the thermostat around 70°F in the winter, which was comfortable, but would still allow us to have a wood fire on occasion and warm the house up to 73-74°F. It’s not that we really needed it, we just liked it. The in-floor hydronic heat can certainly meet our heating requirements. But we’d figured the wood stove would always be our back-up heat in the event of a prolonged power outage or in extremely cold weather. BUT – what if we flipped it and tried a little experiment? Make the wood stove our primary heat source and our in-floor heat the back-up. I’d also received our most recent bill from the power company which advised that our electrical rates had gone up 3% for 2017…so…

Impressively, my wife was game for the idea too. So, on February 1st, we turned the boiler way down, to 65°F, and started loading the wood stove.

My objectives for the month were:

  1. To determine if we would love/hate or be impartial to the need to fill the wood stove in the morning and night.
  2. To determine if we would be comfortable with the house temperature we could maintain.
  3. To determine how much electrical energy we could save by using wood as our primary heat source.

First off, I love our wood burning stove from Morso Denmark. And I love fire. Who doesn’t really? Isn’t their something primordial about sitting around a crackling fire with friends and family? We’d had it a mandatory requirement from day one of the house planning that we would have a wood burning stove in the main living space.

fire2

I’d only ever seen one house with the stove in front of the windows and I think it is a brilliant spot. It doesn’t obstruct our view during the day, but at night the fire gives a nice focal point to the room. This placement also allows it to be viewed from the kitchen, dining room and living room and extend it’s heat range to the bedrooms on the main floor.

We have a wood nook directly opposite the wood stove that is 24″x84″x20″ which contains the mess and also adds another interesting feature to the room.

living1

But enough about design and aesthetics (although I do want to write about that again sometime), let’s talk about function.

My goal was to keep the house around 69°-72°F during the day and a bit cooler at night while we slept.

The month of February was an interesting temperature mix. The first week was stupid cold (-30 to -40°F/C). But then typical for SK, it warmed up to above freezing temperatures for mid-month and then dropped to seasonal temperatures for the last week (-15°C or 5°F). This made it actually a very convenient month to test the wood heat giving us a fair bit of variety.

The first week (very cold week) we burned through the entire wood storage nook. This was surprising to me as I’d only filled it twice the entire winter beforehand! We were going to use up some wood. Basically what I would do is start a fire when I got up (it was good reason to get up and not to hit the snooze button too). The house temperature was around 66°F or 68°F most mornings. I’d get it hot, then load it up and turn the damper down before work. Passive solar gain would keep the house reasonably warm during the day and when we’d get home the house was usually about 69°F. We’d start the fire again and keep it burning until we went to bed, usually trying to get the house temperature up to around 74°F. Again, I’d load up the stove and turn the damper way down before tucking in.

I actually didn’t find this nearly as much work as I thought I would. In fact, I liked it quite a lot. Certainly it’s more work then just getting up and doing nothing, but it really wasn’t bad.

By the second and third weeks, we were in our groove, and the outside temperature was mild. We used half as much wood and the house stayed above 70°F most days and nights, which was higher then we’d had the boiler set at before.

In the last week, we used a bit more wood again, but it didn’t seem like much work. I ended up loading the wood nook three times for the month in total.

We had pine, tamarack, maple and poplar wood that we burned for the month. The pine and tamarack had been what we’d mostly been using for the winter. It’s a soft wood, but has high BTU output, so it burns hot, and also burns quickly. It’s good for a quick warm-up if the house is cooler, but it doesn’t give that prolonged slow burn you might want at night time. It does however burn clean, not giving off a lot of smoke and ash. Maple is a bit better for the prolonged evening slow burn given that it is a hardwood. While the poplar, well, it’s crap. I regret burning it. It’s a dirty wood, very smoky and lots of ash. It’s BTU output is crap too. Oh well. Now I know.

wood

OK so for objectives #1 and #2, I realized that I was generally impartial to the work of loading the stove. We loved the wood heat though. It was comforting and, in fact, most days the house was able to stay above the typical 70°F temperature we’d had the boiler set at previously, which was a nice bonus. Some of the really cold days when you’d wake up to 66°F inside were a bit uncomfortable for the first few minutes until the wood stove got things warmed up. Also, I didn’t really want to be in bare feet on the concrete floors. Even though the house would be warm, we generally would wear slippers.

Now, the big question was, was the extra time/effort worth the energy savings?

This was something that I was most interested in and there was no way to know for sure until I checked out power at month’s end. I’d had the data from 2016 so it was easy to compare the numbers. Based on my notes from February 2016, it was a similar month in terms of average temperature, however as you will see, there are some significant differences. I’m fairly confident that a direct comparison from February 2016 to February 2017 is reasonable. So what did the numbers show? Let me tell you:

February 2016: Solar generated = 553 kWh vs. Overall Energy Use = 2706 kWh

February 2017: Solar generated = 378 kWh vs. Overall Energy Use = 1258 kWh

First off, I was shocked at the overall energy use! It was a massive drop from the previous year. That’s a 64% drop in electrical energy! Wow. I  really did not expect that. And as you can see it’s not like we had an especially sunny month by any means, the solar generation was actually one-third less than last year so we weren’t even getting much passive solar heating.

Needless to say, I was very pleased with these results. When I crunched the numbers a bit more, the cost savings were $177.00 (1448 kWh x $0.12224/kWh)! In a single month. That’s awesome.

Roughly taken over the course of an entire winter that could be upwards of $1000/year in energy savings if we burned wood regularly. And now, well, I’m seriously considering doing just that…

fire3

 

4 thoughts on “The February Experiment: Heating with Wood Fire

  1. I suspect the annual savings could be significant. However, I wonder if it would be as high as $1000. My guess is that regulating the heat with a wood stove during the shoulder months could be a bit more challenging and the savings during those months would be significantly less than in Feb. I’d be interested to read a follow-up on your results for other months if you continue to go that route. Thanks for your post.

    Like

  2. Thanks for posting this blog. I just read through them all. We just started the design process for our high efficiency home and your adventures have been instructive.

    Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s