It should be mixed 60/40 or 50/50 with water. The bulk of the specific heat and thermal conductivity comes from the water and not the glycol.
Don't let it boil, it's pretty nasty when that happens in a lab. The fumes will burn your throat.
Make sure that the corrosion inhibitors are compatible with your plumbing. Each manufacturer uses a different inhibitor and their products are definitely not interchangeable in critical applications.
You'll need to some sort of facility for reclaiming the antifreeze when draining the system, since you're not legally allowed to dump into the sewage system. TTFN