We're at the planning phase of a new build. I'm interested in installing MHRV in conjunction with a ground source heat pump. We've got a 150mm cavity with standard 100mm blocks, and 150mm Xtratherm CavityTherm full fill boards.
Herself desperately wants sliding sash windows, so I'm concerned about air leakage. I won't mention the companys name here, but we're looking at sashes with the following rating:
Thermal Transmittance - 1.4W/m2.K
Solar Factor - 0.45W/m2.K
Effective Air Leakage - 0.01W/m2.K
I haven't been able to draw the conversion from effective air leakage in terms of Watts to air changes by volume.
Wondering if someone can help deciphering how to factor window air leakage into an estimation of how the windows will affect air changes?