We bought a ductless mini split when we built our house. It provides our air conditioning in the summer and heat in the winter. It does an excellent job, 95% of the time. Unfortunately for us, that 5% is when we really need it.
Originally when we were planning our house, Bre and I wanted to go with in floor heat, and I really wish that we had. At the time, however, we couldn’t afford the extra cost involved. Since we were paying for the build without a construction loan, we just didn’t have the funds available. It would have cost us an additional $10,000.
Instead, we went with one mini split unit. Now, these units are becoming more and more efficient. With an average sized home, you can have different units set up in different areas of the house to fine tune temperatures. This can, in theory, save you some money on heat.
Since we live in a cold climate, I wanted to make sure that this would still be a good option for us. In my research, I found reviews from Michigan and New England (relatively similar climates) that had no issues. The Mitsubishi mini-split that we chose was, at the time, the most efficient cold-weather unit.
It was said to operate at 70% efficiency at temperatures below zero. So, I figured that for the two months or so that we averages temperatures below zero, we’d just have to pay a little more electricity to make up for that inefficiency. This would be offset by the other ten months of extreme efficiency.
But Here’s What I Didn’t Know
In all of my research on ductless mini-splits, I never came across this one tidbit of vital importance, so that’s why I’m sharing it with you now. It explicitly states in the owner’s manual that at temperatures below -15, the unit may not even turn on!???!?!
Again, I thought that it would just consume more electricity and run less efficiently, but no, it may not even work. We had to learn this the hard way.
The first time, it was -31. I was at work, and Bre called me at 0130 (because bad things always happen at night) to say that the heat was off. I left work, ran to Walmart to buy some space heaters, and I made it home before everything froze.
That’s when I read through the ENTIRE manual to find out why the ductless mini-split wasn’t working.
Since then, it’s only happened a few times (last night included). Magically, as soon as the temperature rises to -14, the heat has kicked back on. So far at least.
The space heaters are sufficient to keep things from freezing inside, and I’m thankful that we invested in spray foam insulation to keep the temperature from dropping too rapidly. But it’s still an incredibly annoying occurance.
So, in the future, we will have to come up with a supplemental heat source. Ideally, something that doesn’t rely on electricity at all. Because if the electricity goes out, then we’re really in trouble. Or, we could opt for a backup generator.
Initially when we were planning the house, we had allocated a space for a wood stove, but when we actually built the house we scrapped that idea in exchange for a built in bookcase (we have a lot of books). I do wish we could have fit the wood stove as well.
Our next house, or addition, will have in floor heat. We’re in a position now that we can afford it. Even if we had done it originally, I would have liked to have the mini-split just for the dehumidifier and air conditioning because it works supremely well in those aspects. We’re just left a little wanting when it comes to heat, especially on those dangerously cold days.