Frequently Asked Questions about High Efficiency Heating Systems

Please note that the answers given are abbreviated in order to be "short and to the point". The answers are meant to provide a starting point towards further understanding. Further research into these questions is encouraged, or feel free to call CCE. Some books may be referenced elsewhere in this webpage for further information.

What's all of this hype about "radiant floor" heat?
Radiant panel heating refers generally to heat tubing (PEX) laid down in a poured concrete/gypcrete floor, usually during new construction. Since the entire floor surface is the "heating element", your feet feel very comfortable, which makes the rest of you feel good! Also, much lower temperature water can be used to heat the home, which offers two further advantages: It works wonderfully with solar heat systems, and it takes advantage of the high efficiency provided by the newer, more efficient modulating/condensing boilers, by operating them in their low temperature (most efficient) range.

I am renovating the house. I'd like to upgrade to radiant heating, but I don't want to redo my floor to add radiant. What are my options?
There are a few options to consider:

1. You can add a radiant ceiling (pex stapled to ceiling and covered with gypsum wallboard.

2. You can create a radiant wall panel (pex under wallboard).

3. European-style panel radiators - these are attractive, low profile radiators that perform well and look great (see pix in "System Installation Pix" link on home page).
Will I need a boiler in the house to provide backup heat in case the sun doesn't shine?
In almost all cases, yes. Typically, a modulating/condensing boiler is used for backup. When heat in the solar storage tank is depleted, the radiant (typically) system will automatically switch over to the boiler to provide the balance of floor heat necessary to satisfy the home heating load. The modulating/condensing boiler will only come on when the sun can't keep up with the load (mostly in December/January, and decreasing in the "skirt" winter months). Generally, from March thru early October, most of the heat (home heat and domestic hot water) will be provided by the solar system. When it is called upon, the mod/con boiler, which is designed to operate in it's "sweet spot" for efficiency, will use much less fuel than a typical "traditional" boiler.

How reliable are the new mod/con boilers?
Initially, when they came out over ten years ago, they had some problems, but those "early adoption" problems have been eliminated by the manufacturers. Mod/con boilers have become the mainstay of modern hydronic heating systems, are a mature and very reliable product. They have many more programming features than the older generation of boilers. These features provide additional efficiency improvements in addition to their inherently higher burner efficiency. Daily temperature offsets, outdoor, room, and slab temperature sensors, smart circulator controls, etc., ensure significant fuel and electricity savings. Since these boilers are more sopisticated, they should be periodically checked by a trained technician to ensure that they are operating in an optimal state. Checks are recommended every one, two or three years. If desired, the homeowner can perform the simpler checks (system pressure, observing system temperatures, checking some system parameters) using the LCD readout, thus cutting down on the need for technician servicing.

My heating system not only uses a lot of fuel, but my electric bills are also high. How can I cut down on electricity usage on the heating system?
The largest electricity users on a heating system are the various circulators used to move the heating fluid around to where it's needed. A typical heating system in our area runs for about 3500 (+ or-) hours per year. Assuming that you have two circulators running, and they use an average of 200W, that translates to 700kW hrs of electricity. Assuming 10 cents/kW hr, that's $75/yr, just for running the circulators. The newer style ECM circulators, recently introduced from Europe, and used by CCE, use much less power for the same flow rate. Replacing the older circulators with ECM style circulators, the same calculation would be 20W x 3500hrs = 75kW hrs => $7.50/year, which is one tenth the electricity charge when compared to the older circulator style that is used most commonly in today's hydronic systems! Many systems in larger homes have even more circulators, and therefore the elctricity usage is even higher than used in the above example.

Should I use glycol in my heating system pipes?
The answer to this question depends on how well insulated the house is in the area where heating system pipes are located. If there is little chance of freezing, then it's much better NOT to run glycol for the following reasons:
1. Glycol is more viscous, and requires more power from the system circulators. This translates to larger circulators, and higher electrical usage.
2. Water is the most efficient heat transfer substance. Using glycol drops heat transfer efficiency by about 10% (so you have to pump the fluid thru the system a little harder, adding that much more to electricity usage).
3. Any fluid losses in the system need to be replaced with a glycol mixture, which requires a bit more complexity (glycol makeup system or site visit by a heating tech). A pure water based system can have a simpler water makeup valve to make up for such losses.

Despite the above caveats, glycol is needed as an insurance against freezing in many situations. Consult a heating expert when trying to decide!