I see no one has answered your October 9 question. The best way to heat an ac or concrete driveway is with copper tubing set on top of the compacted base material, and embedded in the newly spread hot asphalt or truck dumped concrete. Try to make 3/4 inch continuous trails about nine to twelve inches of separation and run the copper tube to the hot water heater with a shutoff valving system, a drain at the lowest end, and a small recirculation pump that is able to run continuously. 3/4 pipe at 100 foot runs will take about a gallon per 8 feet, or 13 gallons. If your runs are 600 feet long, the hot water supplied would cool off too much to help, if the recirculating pump doesn't run continuously. You can turn the system off and drain it when there;s no need for it, but you don't want to worry about it all through the night, so you would be able to turn the system on, and leave it on for weeks. Electric heated wire is another method, but you know concrete guys, they love to nick and break your wire while they shovel mud.
: Whats the best way to heat a Blacktop Driveway? I'm buildiing
: a new house and want to put one in.