What every best Furnaces has:
- The proper AFUE rating.
- Two stage valves.
- A programmable thermostat.
People love hydronic heat because it eliminates the downsides of forced air -- dry conditions, stale air and circulating dust. Hydronic heat is created when a boiler fires up to heat water that then circulates through the home via pipes to radiators, baseboard heaters or radiant floor heaters. Boilers are relatively silent and cycle off and on less frequently than do forced air systems. In addition, the heat tends to be more stable and even, with fewer cold spots, meaning comfort can be maintained at lower temperatures. Because there is little air circulation, airborne pollutants are significantly reduced.
Hot water heating systems are much less prevalent than forced air heating systems and are most commonly found in older homes. Hot water heating systems are also appearing in some new construction. The cost of replacing a forced air system in an existing home can be high -- pipes, radiators, plus the boiler and installation costs -- but some homeowners are going this route as well.
For new construction or a retrofit, a high-efficiency boiler is a cost-efficient choice over the expected life of the system. Older boilers found in older homes tend to be less efficient than modern units, so replacing one with a high-efficiency boiler with an AFUE rating of 95 percent can result-in enough cost savings to pay for itself over time.
This article from the U.S. Department of Energy advises consumers on choosing the right furnace; and discusses low-, mid- and high-efficiency heating systems. There is also a link to a guide to illustrate the difference in cost of various home heating systems.
These are the most efficient boilers of 2017 according to the U.S. Department of Energy. All of these models have an AFUE rating of 95 percent, except the oil-fired boilers, which have an AFUE of better than 90 percent. Annual operating costs are also detailed.
This site will help detail the possible return on investment for installing a more high-efficiency furnace, or boiler. It includes oil and gas boilers. There is also a brief guide to deciding if you may need to replace your old furnace or boiler.