Hello everyone, I am a GC/owner of a small construction company. I am also a home inspector with another company that I have a business partner in. I have a very broad range of general info about most residential systems and components, and tons of "theory" about how systems work. On top of both businesses, I am renovating my own house, where I am living with my wife, 4 month old baby, 4 cats and 2 dogs. Needless to say, my life is full, unique, and VERY interesting. The reason for all the info is to clarify where my question is coming from . . . . I am starting construction on my master bathroom which will have a large stall shower (approximately 6'x6') with two sets of body jets and three shower heads. Currently, my house has only one bathroom with a typical tub/shower configuration. I installed a gas fired 40 gallon AO Smith water heater just a few years ago. My house is heated with a Peerless gas fired boiler MI-4 series installed in 2006. I am certainly going to need a much greater hot water supply when my new bathroom is complete. My highest priority is having adequate hot water if both my wife and I are showering at the same time. Secondly would be space consumption of the new device, and lastly is fuel consumption. I am willing to pay a higher gas bill if it means a really nice long hot shower. All of this led me to believe that a water to water heat exchanger, if it will provide enough of a heat rise. I have been looking at brazed plate heat exchangers and shell & tube heat exchangers by Brazetek (Removed link to direct purchase site). I understand in theory how these work, and know that it SHOULD do the trick. Again, not being an HVAC specialist or expert, I could really use some direction.
1) What system or design would you recommend?
2) What size heat exchanger?
3) In series or parallel with my existing water heater?
4) What zone controls would you recommend?
5) Any other details, suggestions, recommendations?
Its a 3-story row home, approximately 1800 sq. ft. The bathroom will be on the third floor. There is a pressure pump already installed, and the plumbing supply system is Pex with a 36 port manifold in the basement, just a few feet from the water heater and boiler.
Sorry I'm so "long-winded", and if any more info is needed, please ask.