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by choffee 795 days ago
It feels like that is the least that is required at the moment. There should be more effort getting our current boiler stock up to a lot closer to it's theoretical COP of 1. At least until they can be replaced with something more efficient. Some focus on tuning boiler settings for performance, maybe some aftermarket controllers to do some of this and display the results.

That recoup thing looks really good it always seems a shame to let all that heated water go to waste.

1 comments

I agree, most boilers, left without proper tuning are running below 90% efficiency, most likely about 80%. A 10% increase at the country level would be significant.
I've always wondered if my boiler is set up correctly. I have a closed loop hydronic heater and an indirect-fire tank and when I shut off water to the house ahead of a winter storm I noticed the boiler controller was throwing warnings about short cycling. I'm guessing there's a procedure to tune it correctly but it was probably never followed by the HVAC company since it's very unusual to have a hydronic system with boiler in the US.
As someone with their heat set to a comfortable 18.5C you could also knock a few degrees off the 23C room temperature and save a few of the ice caps.
I use something called Summer Simmer Index, which means that my target temperature takes into account indoor humidity. I feed Home Assistant RAW indoor temperature, and SAT (the integration), converts it to SSI.

https://blog.gcwizard.net/manual/en/summer-simmer-index-perc...

21.3 – 25 °C Somewhat cool. Most people feel comfortable. 25 – 28.3 °C Optimal. Almost everyone feels comfortable. 28.3 – 32.8 °C Somewhat hot. Most people feel comfortable.

I find it hard to believe that most people feel comfortable with 25 – 28.3 °C, how to come up with this numbers? Based on the link above? It seems rather hot. Also it would depend what the outdoor temperature is. But different people have different preferences https://comfort.cbe.berkeley.edu/ (comfort calculator)
I agree, 25 SSI adjusted and above begins to feel too warm but that's why I set it at slightly cool instead.
ahh 19/20/21 based off the chart - that is more reasonable. I probably would not have bothered with the conversion as humidity indoors is fairly consistent and it appears the index is more designed for summer / higher temperatures rather than winter clothing indoors etc.
Yes, it's between 40-60% on average. Here's a snapshot https://snapshots.raintank.io/dashboard/snapshot/OvZOk9eb6gL...