Shoulder Season Fire Strategies

Do you know at what cost per cord your mini split beats firewood? Mine is about $300/cord average for the winter (I dont have good enough hourly/daily data) but it is older and oversized. I would think with a newer, smaller on it would be about $250/cord but you probably do better than that getting log lengths and splitting them yourself.

 

The crossover temperature depends on the outside temperature and cost of wood. The table of efficiency vs. outdoor temperature should be available for every minisplit that earned the energy star rating and/or tax credit eligible. My electricity costs 13 cents per kwh and the cost per kwh of delivered minisplit heat is 6 cents at 32F, 6.5cents at 17F and 4.7 cents at 47F. Buying wood in log form cost me 135$ per cord this year which is just about 3.2 cents per kwh. Market rate for wood is about 275 per cord which is 6.5 cents per kwh.

So it's always cheaper to use firewood based on log costs for me. But, it's pretty close or cheaper to use the mini if you consider market rate wood.

 

Good points! About in line with that I thought given your Kwh is higher than mine ($0.19) and your market rate green wood is more too ($325).

I am thinking now that I work from home I will look into getting log lengths.

Thanks!

 

I should add that my calculations assume cord of wood is 18mmbtu for doug fir and assumed 80% efficiency in my stove. I buy green logs or whatever in June and assume they're green, process right away and into the shed so the fuel gets at least 2 full summers of drying. Log length delivered has been really good for me since I can run saws, cut to my desired length, split to my desired split size, and I usually sell some of the extra to about cover half of the cost of the logs.

If I look close at the expected low temperatures for my area then I can see that it is always cheaper to run the mini than it is to burn 250$ per cord firewood. That's the crossover point on a pure cost per unit of heat basis.

Like I said before though we prefer the silent intense wood heat though. Our minisplit isn't located right in the living room because it's ugly and loud so the heating isn't quite as even as wood heat. We have used it with temperatures in the mid 20s when I had little kids over for thanksgiving and we found that if you leave it on that the whole house eventually gets to be a pretty even comfortable heat. They are effective. As soon as the toddlers went home we sparked up a wood fire!

 

Minisplits are nice for what they do, but the radiant heat off a big iron/steel woodstove is the best thing by far for warming old cold bones! Woodstove heat just feels like comfort to me.