There's and article in the NEWS about using equipment as construction heaters or A/C. Smacna is doing a white papre so hvac contractors can have something authoritative to give GCs and homeowners. Planned to come out early 2005.
There's a survey to fill out on the site http://www.achrnews.com which they will forward to SMACNA. Don't know if you need a subscription to fill it out, but I'm going to mention this thread on the survey just in case. Any input on the subject? Better yet, solutions you've found to this problem.