Hydronic Heating System Configuration
The configuration of my hydronic heating system is described below. I provide this description for those of you who are curious, and for those of you who might want to try something similar.
I am reminded of advice from woodheat.org where they have some experience with hydronic heating using a wood stove. Their viewpoint is, "You would never get enough heat off a wood stove to make a dent in radiant heating needs. If you are lucky, you'll get enough domestic hot water (DHW) for your washing needs."
The folks at woodheat.org are a good source of information, but the contrary individual in me has led me to do what some think isn't possible or practicable. My wood stove hydronic system easily provides 150 degree F water, so I use it to help heat my house. It makes sense to me.
Here is how my hydronic heating system is configured. The discussion below corresponds to this system diagram that will open in a new window so you can shift between the diagram and the discussion below. Starting in the upper right-hand corner of the drawing and moving counter-clockwise, my hydronic heating system configuration and flow path is summarized as:
- Wood stove with internal and external heat exchangers made of black iron pipe.
- Air ejector that swirls water on the outside of the unit, allowing lighter air to come out of suspension and collect in and be released by the automatic air vent. The air ejector is positioned downstream of the wood stove to catch dissolved air that comes out of solution because of the act of heating.
- Expansion tank that compensates for the expansion and contraction of water as it's heated and cooled.
- Water-to-air heat exchanger located in the furnace auxiliary air intake. This allows the furnace recirculation mode to heat the house without using any source of fuel except wood heat from the stove.
- Baseboard heaters that are plumbed in series to heat the hall and bedrooms.
- Pressure relief valve that protects the system should an over pressure situation develop.
- Motor and pump that provides constant circulation in the closed-loop hydronic heating system.
- Sediment bowl that collects heavy pieces of material that might otherwise damage the pump impeller or create clogs in the system.
- Automatic air vent allows air to be vented before being pumped up into the stove.
- Flush valve that allows the system to be flushed of contaminants and air before startup. The flush valve is normally closed during operation of the system.
- Isolation valve that blocks the inlet flow from the flush valve so water entering the system must travel all the way through it before being flushed. The isolation valve is normally open during operation of the system.
- Pressure gauge to show pressure in the system, whether during flush, operation or shut down.
- Fill valve that allows for filling, flushing and pressurizing the system with water. The fill valve is normally closed during operation of the system.
As shown, this is the normal configuration of the hydronic heating system. Various isolation valves, not shown, allow the system to be reconfigured to bypass certain baseboard heaters or the water-to-air heat exchanger. Nevertheless, the system as described and depicted is the normal operating configuration.
Done with Hydronic Heating System, back to Alternative Energy Sources