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Home Comparisons: Goodbye Scores?
🕑 Added 2020-02-25 15:00:03 +0000 UTCFirst of all, the winner of the giveaway for a Sensor two-pack is Derek M. Congrats!
If you asked me which part of beestat I was least happy with, the answer would easily be Home Comparison Scores. They're really neat, and I originally loved the idea of consolidating performance into three simple scores...but now that the honeymoon phase is over I'm realizing just how wrong the idea really is.
Temperature Profiles
Let's take a step back and look at temperature profiles. These are an objective look at how your home and HVAC system perform across the outdoor temperature spectrum. These are the basis for your scores. In general these work well, save for a few issues attributed to solar heating, external heat sources, and other unknown factors.
Scores
Scores are built on top of temperature profiles and are supposed to give you a quick look at how your system is performing. Low resist score? Add some insulation. Low heat score? Maybe it's time for a new compressor or furnace. At least, that was the idea. Turns out there are two problems with scores:
- First, they are subjective. That means that I decided what things were important. Who am I to decide that for everyone, and what am I even basing my decisions on? Spoiler alert: nothing.
- Second, parts of each score are based on an arbitrary quantification of the corresponding temperature profile. That's a fancy way of saying I came up with a number to represent a line. If you know anything about math, you might realize that's not really a good idea.
Goodbye Scores. 👋
I have a whole folder in my inbox of unresolved issues with the scores and profiles. Profiles I can mostly fix, but scores are another story. It's time to say goodbye to the scores...they're a poor representation of system performance and beestat has always been about facts, not opinions.
Hello Metrics! 🎉
I can't take something away without replacing it with something better...and that thing is metrics. The idea is to take all of the individual things a score is built on, then actually show you those things. The above are a few examples, but there could be dozens of individual metrics. Each metric would plot you against all other beestat users in your comparison group so you can see how your system compares against others.
With this approach, beestat goes back to providing facts, not opinions. You, the homeowner, are free to decide what things are important without bearing the burden of a low score. You also get the knowledge you need to make good choices with your HVAC system.
This is a big change, but I believe it's the right one. What are your thoughts?
Comments
I'm one of those people with a weird downward-sloping temperature profile. Maybe that's because I like to throw the windows open in the spring and fall and let mother nature take care of the climate inside my house while it's bearable so to do. I like knowing where I stand versus other ecobee users, but I do wonder if this throws off my year-round comparison data, and metrics seem more grounded in fact. If you go this way, I'd like to be able to compare my metrics now to the same time last year, which might then cater for my anomalous seasonal behaviour and would, as others have said, allow me to identify the benefits of e.g. adding insulation.
I agree with you on the change! Another piece of data to add would be heating and cooling degree days vs run time. With that data one should be able to see a step change after adding insulation, change setpoint etc. But HDD and CDD has to be calculated based on outside temperature and use the balance point of the house. I believe that the higher the setpoint in heat and the lower the balance point, the more energy efficient your home is and vice versa for cooling. Great work so far! What I meant by balance point is the temperature at which your house neither loses or gains heat with no equipment running.
