I have a problem concerning my radiant attic barrier that I don't have the background to resolve.
At the start of the summer I had a radiant barrier coating (e.24, 76% efficient) installed in my house attic. I already had mechanical ventilation (although not enough) and was forestalling the installation of more ventilation until I got the numbers back on the performance of the radiant barrier (radiance brand by Degausa.) I have an attic of similar construction and orientation over my detached garage that has no barrier and little if any ventilation. I installed thermistor temperature sensors connected to a data logger in both attics at similar locations and log the temperature 24/7. The temperature curves, with respect to time, curves are virtually identical. The exception is that the barrier attic seems to heat up a little faster until the fan comes on at which point the two curves line up; it is as though it is trapping heat. Even if the issue is lack of ventilation, as the contractor contends, should I not still expect to see a lag in the temperature rise over time in the treated attic as opposed to the untreated attic. I have also taken interior surface (underside of decking) readings with an infrared sensor (Fluke 61) and detect no noticeable difference.
Either I am measuring this wrong or the barrier is not working. The contractor's expertise seems to be more on the area of installation and less in troubleshooting. They seem convinced that I need more ventilation, but if that is the case of what value is the radiant barrier, I would just merely add a bigger fan... The only real advantage I can detect from the barrier so far, is that one lone light bulb really brightens up the attic now...!
Please help
Thanks John