Replies

1. GBA Editor
   Martin Holladay | Apr 12, 2016 11:02am | #1

   Steven,
   As far as I know, you can install radiant heat under your subfloor if you want (ideally with aluminum heat-transfer plates, as well as adequate insulation below the tubing). An experienced hydronic heating system designer can advise you about water temperatures.

   The first step in any heating system design is to perform a room-by-room heating load calculation. Once you know your loads, you can design your system.

   You should know that the GBA web site usually advises readers to invest most of their remodeling dollars on envelope improvements (air sealing measures, added insulation, and in some cases storm windows) rather than in HVAC system improvements. If you can lower your heating load, you may realize that you don't need in-floor hydronic heat -- it's probable that a simpler, less expensive heating system will work just fine.

2. 
   user-2622918 | Apr 12, 2016 01:23pm | #2

   Thanks for your response Martin, we are working on envelop issues as well, slowly replacing windows and insulation as it comes up during the remodel. It has a brick veneer exterior over what looks to be 1" Styrofoam - brick added in the late 70's. We will be addressing additional insulation in the ceilings as well. Mainly just checking into the feasibility of radiant on the main floor. The original wood furnace is still in the basement - a monstrous cast iron beast that I will be checking out in a few weeks. I expect to need to replace it and as it has a large plenum with a homemade centrifugal blower and filter cabinet that feeds the main floor and has return ducts haphazardly located throughout the building. I was just looking at radiant as a minimally destructive alternative. These ideas are all in the initial planningstages at this time. Thanks, Steve