Double duty on a solar air heater

[gchiu]

I was thinking of getting a SolarVenti solar air collector and installing it on my north west ( southern hemisphere ) wall to heat and ventilate my new office. However, the body corporate for this building is unlikely to sanction it. However, if I put some lettering on the surface, I could then claim it to be novel signage, and I am allowed to put signage up subject to the local council and body corporate approval ( it's a heritage building ).

Just wondering how much of a reduction in efficiency there would be if I did paint some lettering over the glazed portion of the collector.

[russ]

Just calculate the shaded area as compared to the total area - the shaded area is lost.

Big fat letters would not be so great in other words.

Sounds like a good idea.

[gchiu]

I guess there would be less loss if I put the paint on the collector itself inside the box?