Wall parameters by time domain methods: Part 2 - the conduction transfer coefficients a, b, c, and d

It is shown that the heat transfer behaviour of a wall subjected to random excitation can be expressed by four series of coefficients, a0, a1,..., aN, and similar series bn, cn and dn. The number N of such coefficients, typically 4, depends upon the thickness and weight of the wall. The values of dn derive from the first few values of the wall decay times together with the choice of a time interval, typically one hour. an values depend further upon the series of response factors φjee, bn on φjre and cn on φjrr. Values of the wall cyclic transmittance and admittance such as are used in the CIBSE Guide can readily be found from the transfer coefficients. The example given in Part 1 is extended to provide these values.