I just built my first Mysensors sensor (temperature-humidity sensor) and it was successfully integrated in HASS. I extend it further by making a Heat Index sensor using this formula.

Resurrecting an old thread but (hopefully) for good reason.

At home right now itās 18C & 40% inside according to my Nest. That produces a Heat Index of 26 using your formula so I used the simpler Heat Index Formula from http://www.wpc.ncep.noaa.gov/html/heatindex_equation.shtml (last one on the page)

So, pulling the info from my Nest and converting it to Fahrenheit for the equation (but keeping the result in Celsius), my value template looks like this:

The result is 16.9C, which I figure is much more likely given how chilly I feel.

Next step is to write an automation that triggers the AC when the Heat Index rises above the Set Temperatureā¦ Helps me feel warm to think about such things in the middle of winter!

thanks for sharing this. but Iām not sure is this the right one. I have compared the apparent temperature given by dark sky vs the result calculated at https://www.calculator.net/heat-index-calculator.html using the temperature and humidity value from dark sky are quite consistent.

I was just rereading this thread after I came across it again. I just realized we had very different goals in mind.

The heat index calculation youāre using is, in fact, the correct calculation for outdoor āfeels likeā temperatures. My goal was to calculate a āfeels likeā temperature for the indoors, which is a very different calculationānote the NOAA formula is only accurate down to 80 degrees F, which would definitely be outside my comfort zone for an indoor temperature.

My usage is primarly for the purpose of tweaking indoor thermostat settings based on a āfeels likeā temperature rather than an absolute temperature.

Hopefully, that clarifies the use-case and reasoning behind the different formula.

Thanks ā this is nearly what I was looking for. I have also realised that even indoor airflow (through fans and ventilators) affect the comfort level.

Is there a method we can first measure indoor air velocity and then use it to tweak the thermostats.

Iām a bit confused with the above calculations, as the UK Meterology Office describes outdoor āFeels Likeā temperature as a measurement of temp/humidity/windspeed at a height of 5ft. Unless Iām missing something I donāt see windspeed integrated in those calcs. If I find the calculation for this missing piece of info, Iāll post it here.

Are you still using this formula for indoor? How has it worked for you?
Iām looking into implementing something like that for my home and I think what you wanted is exactly what I want to do.
Could you tell me if you have noticed a difference by using the feeling temperature compared to the real temp?

Thereās generally not a vast difference between the measured temperature and the feels-like temperature. For example, right now thereās only a one-degree difference between the feels-like temperature upstairs and the actual temperature (69.8 vs. 68.8) and thatās with 66% humidity.

I was going to try to look at a historical graph and discovered that history doesnāt record derived values, unfortunately. Otherwise, I might have been able to see how much of a delta I saw between the two.

If youāre interested in picking up a 1-2 degree difference, it might be useful; otherwise, itās more of a novelty, I think. To answer your question more directly, the only place I leveraged the feels-like temperature is in determining whether to switch over between A/C and Heat. Otherwise, my house uses the thermostat temperature as you would normally.