I am planning an addition to my house and considering hydronic radiant heat floors as the only option for heating the new addition and some existing areas like bath. I have problems finding any knowledgeable HVAC contractor who has experience in hydronic heat and can give me an unbiased honest advice and help me design the system.
I spent quite a time researching the subject online but got completely different opinions. I would really appreciate if someone with the knowledge would tell me, what heat source is preferred in my case and what the whole system consists of.
The addition is ~1500sf, I live in central NJ, the fuel is NG. Current heating is forced air furnace, I do not want to touch it, new system will be an addition, not replacement. The addition will include big room on slab foundation and second story area. The house will be well insulated: all attics R-49, walls R-19.5, floors under second story addition will be probably R-30 and the slab will have at least 2" (R-13) foam insulation. All windows are E4 Andersen windows.
I want at least two zone hydronic system for new addition: one is for big room on the slab and another for second story area. I intend embedding PEX tubes into the slab, tired them to rebar, and for second story with hardwood floors I will put plywood panels with grooves and aluminum backing and run the PEX tube inside the grooves.
I have very limited space in my basement where new system can be installed. So the ideal approach for me for the heat source would be radiant heat source and water heater combination unit that does not take much floor space. This unit will also replace existing NG water heater and provide hot water for entire house. Especial value for me would be the system that I can at least partially DIY.
Any advice would be greatly appreciated.