Heating and Solar Thermal Panels

In an earlier post I mentioned the dilemma of tearing down an old house. Well after living for 5 years in an old house and now an old apartment building that could not be draftier, I have no regrets. In the house we sold in Bucktown and our current rental, if I lit a match near a window or door it would get blown out. So with single digit temperatures here in Chicago, we are glad that Nate and Dan, our architects, have thoroughly thought through the heating aspects of our home.

It has been below zero several times this winter in Chicago. It was so cold a couple weeks back, that when a client of mine who lives in Italy was in town on business he called home to ask his wife what temperature they had their freezer set at. He then told her that it was warmer in that freezer than it was outside in Chicago. Without the accent, the story likely is not as funny.

In addition to a very well insulated and sealed house, we are doing radiant floor heating, a furnace (required by Chicago code) and a fireplace. Too many heating sources? I may agree, but see the paragraph above. We are most excited about the radiant floor heating in the basement and first floor. We decided that it was not needed for the second floor as the heat will rise to reduce the heating needs there and maybe we can use the furnace for something. However, we did put an electric radiant floor system in the master bath. The radiant floor system should create a much healthier home. Not having dust mites continually being blown through the house might be nice.

The fireplace design has been a wild ride that I am not sure I am ready to talk about. The original plan called for a crazy Russian fireplace that had an equally crazy price tag, which was eliminated immediately after the bids came back. We currently have a fairly standard fireplace that will have a nice bench around it, all surrounded by some cool tile.

The main thing I wanted to talk about was the solar thermal system. This has nothing to do with generating electricity, which are called solar photovoltaic systems and are currently cost prohibitive in Illinois (28 year payback period). The solar thermal system that we are installing works like a car radiator, but in reverse. The panels will gather heat from the sun, heat up an anti-freeze type substance and send the substance down to the basement to heat water in a 120 gallon tank. The anti-freeze is designed to get to 180 - 200 degrees.

There will be sensors on the hot water heater and the radiant floor heating boiler. If water in the solar thermal tank is hotter than the water in the hot water heater, the water going to the hot water heater will be diverted to the solar thermal tank. Adding hot water from the solar thermal tank to the hot water heater will reduce the gas needs for heating the hot water heater. A similar process will happen with the radiant floor heating, if the water that gets sent out from the radiant floor boiler to the floors returns cooler than the solar thermal tank, the water will be diverted to the solar thermal tank before returning to the radiant floor boiler, reducing the gas needs of the radiant floor boiler.

Joe from our solar provider, Solar Services http://www.solarserviceinc.com, was great at explaining the process. He also had a significant amount of data to make a compelling argument for installing a solar thermal system. A house like ours will likely use 1200 - 1500 thermal units a year and our system should provide around 500 of those units. To put this in perspective in Chicago though, we will likely have all our heating needs (mainly the hot water heater) provided for 8 months of the year. When it gets cold in Chicago, this will be a good supplement to our heating needs.

I was sold on the concept when I met with Solar Services; however, I wanted a lower price and some transparency. Transparency in the building trades is an oxymoron, so don't ever try it. The big item that Solar Services is helping us with is the application for a state grant that is expected to give us a 30% rebate on the system's cost. There may even be a $2,000 tax credit involved at the federal level. Wish us luck.