I will be installing a water/air exchanger from an outdoor coal boiler into my furnace plenum. There are a number of things I need to consider when doing this. The boiler is a bit oversized so one concern is short cycling of the boiler. To make this more complicated I only want to heat a portion of my house meaning I'll be shutting down registers causing potential excess pressure within the duct work. There are a number of things I need to consider and want to run this by a few people here. My furnace blower is the permanent split capacitor (PSC) type and from what I've read closing registers will cause this blower to work harder, stress the unit, and slow it down. I believe I can lower speed and be ok as long as I take measurements and stay within a static pressure of appr 0.5 inches water column. Once I find that I can work apply heat to my water/air exchanger. I could measure the temperature rise across the heat exchanger to make sure it's within manufacturer's specs. AI could verify I'm ok by measuring supply and return temperatures on my boiler to ensure I'm at a Delta T of 20. If I'm not pulling enough heat off the exchanger I could either manually slow the rate of water flow to the exchanger and/or lower my boiler temperature (not a bad thing). I could also pull more heat by installing a radiator or two if needed. There will be no oil fire so I won't have to worry about flue gasses. Not sure if I'm missing anything. Any other measurements anyone can think of I may want to consider? Any other thoughts? Thanks in advance

I have an unusual application I need some help with. We own a private railroad passenger car. It’s basically a giant RV with four bedrooms, a living room, a dining room, and full kitchen, etc. Mainly, it’s used behind Amtrak trains throughout the US, but we also do some work escorting high-value shipments on freight trains in the US and Canada. Electrical power for the car comes from either a set of cables under the floor that run to the locomotive or to ground power, or from an onboard diesel generator with a 65 kw capacity. The large loads operate at 480 VAC three-phase, with transformers supplying 208/120 wye for the smaller loads. Heating for the car is from an electric boiler of my own design that uses screwplug immersion heaters to heat an antifreeze/water mixture that is circulated throughout the car. The heaters are regulated by SCR power controllers that are run from a temperature controller that reads a thermistor in the outlet piping of the heater. There are also thermostats and safeties to keep the whole thing from going nuclear. A set of contactors allows us to run one element (18 kw) or all three (45 kw) as needed for summer or winter operation. There are four heating loops in the car: one on each side for baseboard radiators, a heating coil in the ventilation system, and one loop that runs continuously through the fresh water tank underneath the car to prevent freezing. The three loops inside the car have proportional control valves that are run from a modular control panel. We can change seamlessly from heating to cooling and back without ever touching the controls. The heating works great, and maintained 74 degrees inside with an outside temperature of -42 F in Canada in February. When I built the system several years ago, I intended to switch the domestic hot water heating to run off the main heating boiler. Right now, it uses a 30-gallon household electric hot water heater. I would like to use a heat exchanger to heat the domestic hot water, mostly to free up the large space taken up by the 30-gallon tank. How should I pipe this? My plan was to use a three-way valve in the loop that goes out to the fresh water tank. Depending on the heat load, some of the water would go first into the heat exchanger before going out to the fresh water tank. I am less sure about the domestic hot water side of things. The current setup circulates water from the water heater to provide instant hot water. There is one sink that is 40 feet from the water heater, and we can’t afford to waste any waiting for hot water. How would that loop work with a heat exchanger? Does it make sense to include a smaller “buffer” tank that would help prevent the cold rush of many tankless water heater designs I have seen? Any other suggestions? Can you feel the cold? [URL=http://smg.photobucket.com/user/llafro/media/Icy%20Tioga%20Pass_zpso6nfco6v.jpg.html][IMG]http://img.photobucket.com/albums/v653/llafro/Icy%20Tioga%20Pass_zpso6nfco6v.jpg[/IMG][/URL] [URL=http://smg.photobucket.com/user/llafro/media/COLD_zpseoh2dqcc.jpg.html][IMG]http://img.photobucket.com/albums/v653/llafro/COLD_zpseoh2dqcc.jpg[/IMG][/URL]