Q:
Two heating contractors have told me that switching from steam heat to a hot-water system would pay for itself ($6,500) in five to six years. They said that we could use the existing pipes and radiators. This sounds too good to be true. Is it?
Lin and Lezetta Moyer, Takoma Park, MD
A:
Heating contractor Mark Eatherton replies: Unfortunately, knowledgeable steamheating contractors are getting hard to find. Consequently, heating contractors who don’t understand steam recommend changing to a system that they understand better, specifically hot water.
A system replacement could result in a significant fuel savings for you, but without seeing the heating system as a whole, it is hard for me to say for certain. However, I can offer you some generalities.
Regarding efficiency, the lower the operating temperature, the more efficient the system can be. Steam systems are the least efficient (70% to 80% efficient) because of their high operating temperature (212°F). A hydronic radiant-floor heating system has the lowest operating temperature and is therefore the most efficient (80% to 98%). Your proposed steam-to-hot-water conversion probably would fall somewhere between these efficiency ranges.
The smartest thing to do is to find someone who is competent in assessing your existing steam system. A contractor with expertise in steam and hot-water heat should be able to make low-cost, fuel-saving recommendations.
