Free Pipe Type 205
by International Energy Agency

	This model comes from the simplified model of the data bank (S13).
??? Two more simplifications are made:
1)  The temperature at the outer pipe surface is taken equal to the 
    water supply temperature.
2)  1/AU is supposed equal to 1/hoAo

No dynamic nor time delay are taken into account.
ho = hr + hc
hr = 5.7 E-8*E*(Tsu**2 + Tamb**2)*(Tsu + Tamb)

hc = 1.3*(tsu - tamb)**1/3       for vertical pipes
hc = 1.3*((tsu - tamb)/D)**1/4   for horizontal pipes

Q = m*cp*(tsu - tex)

Ref: IEA ANNEX17:BEMS Synthesis Report  Univ. of Stuttgart
        JUne 27, 1991  AN17-910627-01