The air temperature was 83°f. The pavers had full sun exposure all day. The two hour test, during the hottest part of the day, yielded exceptional results. ~76°f water was pumped through a ten panel test system beneath a medium grey, ground mounted paver walkway in Portsmouth, NH.
The system had an average flow rate of 1.342 GPM and an average ?T (temperature differential) of 9.96°f. During the two hour test, 4.6 kWh of energy was exchanged. This is equal to approximately 15,695.85 Btus or 196.2 Btus /sq ft/ hr. The control area of the sidewalk with no ThermaPAVER units installed remained at approximately 150°f.
http://media.wix.com/ugd//1e8dd3_41aa95fa99023d11bd9218c6a2ba9f8c.pdf
