> Of John S. Ward >Just because you can't feel the difference doesn't mean others don't.
I think it is entirely possible that the median JND for room temperature is less than one degree Celsius. The following is not an argument against that possibility, but I think it is still relevant....... A thermostat displays a single temperature to the user (e.g. 22 degrees Celsius), but it actually measures two temperatures. The lower temperature turns the heating on, the upper turns it off. I would be surprised if domestic room temperatures are maintained to +/- 0.5 degree Fahrenheit of the thermostat setting. If there are two installations and one produces actual room temperatures over a 3 degree range (20.5 to 23.5) and another produces a 1 degree range (21.5 to 22.5), then our perception of comfort will be different. At any given setting, we are more likely to be dissatisfied with the upper or lower temperatures produced by wider range installation. Consequently we will want to make smaller adjustments. Thus experience with a thermostat in a particular installation is not necessarily a good indication of JND.
