Is this right or total tosh???

[Roger]

The message from Capitol contains these words:

So you think but that only goes to show you are losing your marbles and may soon join Dribble in never-never land where reality is whatever you want it to be.

Well there my have been one or two changes along the way particularly with units. Even ISO metric is different in some ways to the cgs and mks we were taught at school.

Right total emissivity of aluminium at 100C 0.09, oil paint 0.92 - 0.96. Whoops stupid reference book must be wrong. Capitol has decreed that they should be much the same.

In the real world there is a temperature gradient from the heat source to the environment at large (unless the heat source is largely radiant). In the simplest example where the interior walls of a room are heated to the same temperature on both sides there would be no heat loss through the internal walls and little or no temperature gradient across the room if there was a full width radiator across the outside wall. Reverse the situation with the radiator across the opposite wall and you will get a significant temperature drop across the room. The more poorly insulated the outside wall, the bigger the drop and the larger the convection currents within the room.

[Dave Plowman (News)]

It's even nicer to come down to an already warm kitchen. ;-)

[Roger]

The message from Capitol contains these words:

FWIW a few figures from my house taken during the day and into this evening. Make of them what you will.

S. Window Room centre N.window

Kitchen 62F 64F 58F Living Room 62F (55) 66F 66F (55)

No prizes for guessing where the radiators are. :-)

Windows in question are all wooden framed and standard double glazed. Temperatures taken with a mercury max/min in line with the frame at a height of approximately 3' 8" from the floor and the thermometer was allowed to acclimatise for some time at each location.. Living room stat set at 19C all day.

Kitchen temperatures taken middle/late morning. Living room middle afternoon except the figures in brackets which were in early evening with the curtains closed. The anomaly with that pair of readings is probably due to the North window having thicker curtains and a 18" gap between curtain and glass while the South window has thinner curtains and only an 8" gap.

[Capitol]

OK, so now you have to move the radiators and repeat the exercise? BTW What anomaly?

FWIW, I regard anything below 75F as Arctic.

An IR thermometer makes life a lot easier and really helps you pin down heat loss problems.

LOL

Capitol

[Roger]

The message from Capitol contains these words:

snip

Why? In any case I have no intention of moving the kitchen sink and I am not inclined to dispose of the window seat either.

The anomaly that with the curtains closed the window temperature was the same for both the North and South windows. Anyway those figures were wrong. Having carefully checked the thermostat when I was taking readings during the day I neglected to do so in the evening and shortly after I had posted the figures my legs felt cold. On checking the thermostat display I found the room temperature was down to 16.5C. The boiler overheat had fired for the second time this year so perhaps I will have to do something about that soon. I thought it a bit odd at the time that every time I moved the thermometer the temperature went down but at the time I put it down to the declining outside temperature.

The anomaly remains but at 60F rather than 55F.

Old age. :-) My father was like that in his 80s. I usually run my house at 17C during the day but pushed it up to 19 today in order to get more consistent results.

I have one as it happens but I don't trust it to give an absolute figure. Something to do with emissivity of different surfaces you know.