The ultimate comfort system Part 2

What's in a name? When I decided to undertake this project, it was my goal to show other contractors and designers that it was possible, in fact feasible, to retrofit an existing dwelling and approach near net-zero energy production. While the project home is and will continue to be on the grid, it is my hope that I can generate enough energy to eventually take the home completely off the grid at some point in the future. Obviously, I will be phasing in the different elements, other than emitters, over a period of time approaching five years.

When it came time to name the project, I wanted its name to reflect the primary means of heat transportation and the final goal of my efforts as a whole — that being total comfort, hence, the name Hydronic-ahhh. I originally wanted to name the place ZanaX Ranch because of its soothing effect on people's souls, but my lovely wife reminded me that I would probably be hearing from some drug company's legal department, regarding patented name protection, so I settled on Hydronicahh.

Before I get into the hardware details of the heat sources, I want to cover the different heat emitters, and why I chose to utilize the components where I did. Remember, this is a demonstration site where I can showcase some state-of-the-art applications and some not so state-of-the-art applications. Let's start with the obvious one — the radiant floor.

The radiant floor system will be limited to the bathroom, which has a small foot print around 35-sq.ft. Also, contrary to the project name, the floor will not be hydronic. Instead it will be electric radiant. I had many reasons for choosing electric radiant for this application. Convenience was more important than all of the other reasons. I wanted to be able to turn the radiant floor on, so it will emit heat in a short period of time. I also wanted to be able to use the excess electrical power that the system will be generating and use it to maintain a high mean radiant temperature within the high mass environment. The system will operate with up to 48 volts DC power, which means I can draw the power directly off of the electrical storage batteries, thereby avoiding the inverter losses, making this part of the system as efficient as possible.

The bathroom is the only place I chose to have radiant floors because that is the one room that has a high chance of having occupants in it that will be scantily clothed and most probably wet at times. The room is an interior room with no exterior walls, so the actual heat loss requirements are limited to the ceiling heat loss, which will be rather minimal. I intend to install some rather thick tile on the floors and thick walls to add mass to the equation, which will give me plenty of flywheel mass effect to help maintain reasonable conditions during less than ideal solar gain conditions. In addition to the electric radiant floor, I will also have an electric glass towel warmer. It too will be tied to the battery storage system to avoid unnecessary inverter loss and increased thermal performance.

The towel warmer will run continuously, and the floor will be operated on a sophisticated programmable set-back thermostat that has intelligent ramping capabilities to insure that the floor is warm when I want it to be warm, which is typically in the morning and at night.

Although I could have done radiant floors throughout the dwelling, due to structural considerations and height considerations, I opted not to utilize radiant floors throughout the entire house. Instead I chose to use it in the one area where it was most appropriate.

Don't get me wrong, I love my radiant floor heating systems in my other home, but I wanted to prove that it is possible to deliver radiant comfort without the need of radiant floors. I have publicly stated before that I think one of the most overlooked opportunities for providing good human comfort is radiant ceilings. With ceilings, the consumer can cover the floor with what ever tickles their fancy and not affect their overall comfort factor. It also doesn't affect the final structural considerations like above floor radiant heating systems would. No need to raise counters and doors to accommodate the increased floor height. Tune in next month as we continue our adventures at Hydronicahh. Until then, happy near net-zero energy consuming!

Mark Eatherton is a Denver-based hydronics contractor. He can be reached via e-mail at [email protected] or by phone at 720-479-9313.