Well Gang,
After reading this thread and all the responders, we took our coach, an '04 Itasca Horizon 36GD with the C-7 330HP CAT out last night for a fuel up in prep for a trip on Monday. The outside temp was fluctuating around 53-56 degrees, based on the reported temp on dash gauge. And, while on the way back home from the fuel station, I put the heater on the floor and, turned the speed up to 3/4 of the way.
Now, this was after about a 4 mile run, from our home, on city streets (I really can't get it up to good road speed using this route)to the fueling station. And, on the way back, was my "heater" test. Well, I can say for sure, it heats my foot area pretty darn nice. I reached down while driving and could feel a ton of air coming out of the foot vents and, it was not "HOT" but, it was darn warm.
Now, the wife couldn't tell 'cause her feet don't touch the floor when she's in the Co-pilots seat. This is a Freightliner "Evolution" XC Chassis. We don't run in that cold of weather on most of our trips so, the use of the heater, is a bit rare for us. We use the A/C waaaaay more than the heater. So, anyway, that's the report from this Freightliner chassis owner on the front heater area situation.
Scott