I moved into a new home 6 months ago and found there are some problems with insulation, nothing I can’t handle as I’m doing renovations anyway, but I got to thinking about how I can track the improvements.
I have a weather sensor outside to track realtime external temp, temp sensors in all the rooms, and Wiser thermostat with TRV’s in the main rooms.
In theory, as I make improvements my average score throughout the day should get closer to 0. But it takes into account how cold it is outside, so if there is a large delta between the internal temp and the external, but the internal does not quite match the target, then the number will still be closer to 0 even if only slightly
I can also compare this with Gas usage (Gas combi) to see how I’m doing on that front.
This is very early days, so it might not work out, but this is the direction I’m trying to go in to see what impact all the insulation and renovation have on the comfort of my house temp.
Has anyone else done anything like this before or have any thoughts or suggestions?
I have been doing something similar, gradually doing some air sealing and adding insulation in my attic. I think the metric you are likely looking for is something similar to what is known as the “design heating load”. This is the amount of heat you need to supply to your house in order to keep it at a desired temperature (I think 68F is usually used as the indoor target temperature) and the 99% design temperature (the temperature which the outdoor temperature will be above 99% of the hours in a year, on average). If you hired an engineer they would try to calculate it using something called a Manual J from the ACCA. You can also get a rough estimate based on your fuel use using the method described here Replacing a Furnace or Boiler - GreenBuildingAdvisor. Ideally you could calculate your design heat loss before you make changes and compare it to the loss after and that will tell you how effective your insulating efforts were.
One of my goals is to try to come up with some model for estimating the heating load of my house at various outdoor temperatures based on the furnace runtime data HA is collecting for me, the thought being I can multiply the duty cycle of my furnace by the rated heat output (40,000btu in my case) to calculate the heat loss. It sounds like you have radiators so that calculation would likely be a little more difficult, you would have to try to calculate the heat output of each rad, multiply that by the respective duty cycles, and then add them all up.
I should be able to get a good idea of the accuracy of the calculations this weekend. We are forecast to be below our design temperature of -3F for at least 48hrs, and I calculated our design load at a little less that 40kbtu, so I should see the furnace running at 100% for a while, but in theory it should be able to stay on the low fire stage.
I’ll have to dig into this, looks like what I am after. I have quite a bit of logging. I believe my Boiler measures the gas usage for just heating but I would have to copy it out as there is no integration and it’s through a digital menu system.