I had recently completed my cogen part of my 12/2 project. if you recall, I heat exchanged through my very big heatx. I connected the secondary loop to three eight foot hot water baseboard heaters (15000-16000btu at 180 deg F.), located in my house addition 60 ft away. I wish I would have added one or two more heaters. Now, with the three eight foot sections, at 75% load, the secondary supply side works its way up to about 182 deg. F. I measured a one degree drop in the feed to the house, and approximately a 15 degree drop through the heaters. The secondary loop inlet to the heatx is about 15 degrees lower then the outlet. My primary loop fluid runs continuously (195 deg T-Stat remains open), the outlet cooling casting max's out at around 215 deg. or so, with nearby head temp slightly lower. A little too close for my comfort, I think. My saving grace, is that I have other secondary loops that can also be selected, one that heats up my oil storage area. I hope this info helps.