[esp-r] Re: thermal lag

[Jon Hand (clcv10)]

A recent question about thermal lag:

> Has anyone got info on how I'd use esp-r to calculate the thermal  
> lag of a construction?

This depends on your definition of thermal lag.

The simulator scans all of the constructions used in a model and  
finds the
Fourier number and uses that to calculate the number of startup days.

There is a function (can't think of exactly where at the moment) to  
calculate
the approximate parameters used in the Admittance method.

And if you run a simulation with save option 3 you can get an animation
of the temperatures within a wall.  SO how about a VIRTUAL test.  Set up
a boundary condition that is static for X days and then give a  
substantial
pulse of temperature or radiation and then just observe how long it
takes that pulse to show up on the other side of the wall.  Note: if
you are tracking a 2m thick stone wall you could be waiting quite
some time and you might need a rather strong pulse to ensure it
can be tracked ;-)

-ESRU