Mark wrote:
On 05 Feb 2009 10:28:38 GMT, (Andrew
Gabriel) wrote:
It seems to be a common misconception that the TRV sets the radiator
temperature. It doesn't - it sets the room temperature. The radiator
temperature is likely to swing all over the place in its effort to
maintain the room temperature, particularly given that the hot supply
to the radiator is likely to be cycling on and off from the boiler too.
However the closeness of the TRV to the radiator has often make me
suspect that they may shut off the rad before the room has reached the
selected temperature.
In the last cold snap I tired an experiment, in that I put a 6" desk
fan running at its lowest speed under the 800 x 600 double radiator in
the lounge, in an open-plan sixties design house.
The result was astonishing. In ten minutes, the thermometer at the
other end of the lounge showed an increase of 1 degC (21.5 to
22.5degC), the temperature felt far more even across the lounge, and
the TRV ran the system exactly: a setting of '4' gives the calibrated
21 degC, '5' gives 24 degC, and the interpolation is also correct:
'4.5' gives 22.5 degC.
The TRV is out of the direct air stream, and the lounge is noticeably
more comfortable (but not necessarily warmer).