I have the logstor pipe to install but was wondering about pipe size inside. Is 1" pex big enough? I.D. is about 7/8". Saw another post that said 1" pex only carries 80k btu. Im trying to heat about 3k sq ft and hot water. I have plenty of furnace (400dcs heatmor good for 10k sq ft) I bought it used and have a 140k btu air exchanger. Do I need bigger? Also want someone to tell me Im installing the water exchanger right. If nothing else youll get a kick out of my labeling......top notch!!lol...