1. Softened water does remove the potential for scaling but it does increase the potential for galvanic corrosion with the salts that are added (replacing magnesium and calcium). For closed loop systems, RO or demineralized water is your best bet along with a quality inhibitor. At this point I would recommend isolating the system from the water supply in your home to prevent any of your water supply from entering the system in the case of a leak. This will only be a viable option if it is a closed system where you're not continually adding fresh water. If your wood boiler is open and you're having to add water on a regular basis I would highly recommend isolating the wood boiler from the rest of the components using a plate heat exchanger. This does add complexity but it certainly isolates a lot of the dirty water problems to the wood boiler, piping and heat exchanger and keeps it out of the rest of your system.
2. Any dirt separation device should be on the common return before the appliance and pumps whereas air separators are most effective between the heat source and the pump. By placing the dirt separator upstream of the air separator this would make your expansion tank placement no problem. I would also recommend a good flush of the system using high velocity flow.
Best Regards,
Cody Mack
Applications Engineer
Caleffi North America
414-238-2360
Richard,
Thanks for your comments and questions!
1. Softened water does remove the potential for scaling but it does increase the potential for galvanic corrosion with the salts that are added (replacing magnesium and calcium). For closed loop systems, RO or demineralized water is your best bet along with a quality inhibitor. At this point I would recommend isolating the system from the water supply in your home to prevent any of your water supply from entering the system in the case of a leak. This will only be a viable option if it is a closed system where you're not continually adding fresh water. If your wood boiler is open and you're having to add water on a regular basis I would highly recommend isolating the wood boiler from the rest of the components using a plate heat exchanger. This does add complexity but it certainly isolates a lot of the dirty water problems to the wood boiler, piping and heat exchanger and keeps it out of the rest of your system.
2. Any dirt separation device should be on the common return before the appliance and pumps whereas air separators are most effective between the heat source and the pump. By placing the dirt separator upstream of the air separator this would make your expansion tank placement no problem. I would also recommend a good flush of the system using high velocity flow.
Best Regards,
Cody Mack
Applications Engineer
Caleffi North America
414-238-2360