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Hydro Air

Dan_15 Member Posts: 388
Hi--I am a homeowner, been lurking here for a long time and trying to learn what I can.  I am looking at an opportunity to completely gut and rehab an old new england home, and I am trying to get my brain around whether to replace the exisitng heating system.  The home currently has hot water heat with standing cast iron emitters and of course needs a boiler upgrade.  I would most likely want to upgrade to a condensing gas boiler with reset control strategy and indirect hot water.  We also want to install an AC system.  I have to assume the existing radiation will become way too much once the house is tightened up with insulation and new windows.  What do you guys think of hydro-air in general? Hydro air seems like a good option for a new install where the goal is to utilize same ducting for heat and AC.  Can a hydro air system be used with a condensing gas boiler with reset control strategy?  Would you totally replace the existing system or would you keep it and add on an AC system?  What are the considerations I should be thinking about? What would you guys do in this situation?

Any advice is much appreciated.

Thanks, Dan


  • LarryC
    LarryC Member Posts: 331
    Split AC units and upgrade existing heating system

    Since the duct sizes and grill locations for AC and heating are very different, and you are up in New England, install split AC systems only in the rooms that need them.  That way you don't have ducts taking up space and then suffering with a wind storm everytime the main fan turns on.

    If you are doing the full gut, radiant floors or walls or ceilings may be a good approach especially if floor space is at a premium.
  • Big Ed_4
    Big Ed_4 Member Posts: 2,785
    Condensing Efficiency

    To maintain those high number efficiencies with a condensing boiler you need low temperature returning water, Like you would get from large mass radiation .I guess you could achieve this with a large enough or multiple coils up in your air handler ...

    I would keep the systems separate , Design a proper size AC system and heating system for the home.. I like radiant heat in slabs ,walls or ceilings .. ,Not big on wood floors as others might .. Over size panel radiators are another option of mine with a condensing boiler ...
    I have enough experience to know , that I dont know it all
  • Dan_15
    Dan_15 Member Posts: 388

    Thanks for your replies.

  • Nick S
    Nick S Member Posts: 62
    Keep the radiators

    Your right that your old radiators will be over sized with the added insulation and air sealing, but that is exactly what you want with a mod/con boiler. You will be able to heat your home with a much lower water temperature than your old system and with outdoor reset, you will be probably be more comfortable too.
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