Radiant barrier delima


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
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"A radiant barrier reflects radiant heat energy instead of trying to absorb it. What does this mean in your home or business? During the winter, 50-75% of heat loss through the ceiling/roofing system and 65-80% of heat loss through walls is radiant. In the summer, up to 93% of heat gain is radiant. If you are depending on R-value (resistance) alone to insulate against heat gain and loss, remember that thin layers of fiberglass are virtually transparent to radiant energy and are affected by changes in humidity (moisture levels). A 1-1/2% change in the moisture content of fiberglass insulation will result in a 36% decrease in performance (referenced from HVAC Manual 10.6; McGraw-Hill). A pure aluminum radiant barrier is unaffected by humidity and will continue to perform at a consistent level no matter how humid it may be." more at: http://www.radiantbarrier.com/what_is_radiant_barrier.htm
where is the barrier?
The Quintessential Man... wrote:

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No way :-) An R30 wall plus a radiant barrier might be R33 at best.

No. With no moisture protection, it will oxidize and perform poorly.
Nick
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