Comfort Line - Questions and Answers

This quarter our question and answer segment discusses the unique energy-saving features of the German boiler system offered by Hart & Iliff.

Why are German heating systems different from systems sold in the United States?

Fuel prices in Europe are historically higher and environmental regulations stricter than in the U.S. Consequently, European heating systems are designed to extract the maximum amount of energy out of a gallon of fuel. Eighty percent of all homes in the U.S. are heated with warm air. In Europe, homes are heated with inherently more efficient hydronic (hot water) systems. In addition, Europeans use standalone radiators and radiant underfloor heating systems instead of copper fin tube baseboard, which is common in this country in homes heated with hot water.

How is the design of German boilers different from those manufactured in the U.S.?

Boilers are sized based on the heating load, as measured in BTUs, of the home or area to be heated. In the American market, there are generally two or three boiler sizes to handle the most common BTU heating ranges. For example, one well-known American boiler manufacturer offers two boiler sizes to cover the entire heating range between 65,000 and 205,000 BTUs. In contrast, a well-know European manufacturer offers seven different boiler sizes to cover the same heating range.

The American manufacturers’ mentality of one size fits all is the equivalent of putting a size 10 foot into a size 12 shoe. Obviously, the more accurately the boiler is sized to the heating load, the less energy it will use.

The difference between the constant high operating temperature of conventional boilers (typically 180°F) and the optimized water temperatures of a German boiler means significant fuel savings.

European manufacturers also use a three pass boiler design to extract the maximum amount of energy out of the fuel and a unique boiler operating control called indoor/outdoor setback. This control improves the comfort level in the home and dramatically reduces fuel consumption.

How do indoor/outdoor setback controls work?

The concept, which is really quite simple, is similar to cruise control in a car. During the course of a heating season, your boiler fires up and shuts down thousands of times. American boilers use 180°F water to heat, regardless of the outdoor temperature. The European indoor/outdoor setback control adjusts or modulates the temperature of the water in the boiler depending upon the outdoor temperature.

For example, when the outdoor temperature is 50°F, the boiler water temperature might be only 110°F. With indoor/ outdoor setback the boiler water temperature will only be 180°F on the coldest days of the year. Instead of heating the boiler water to 180°F each time there is a call for heat, the indoor/outdoor setback control heats the boiler to the lowest temperature needed to keep the house comfortable. This results in fuel consumption savings in the range of 30%-40%.

In addition, your comfort level is enhanced since the heating system delivers a moderate amount of heat on a constant basis rather than intermittent heating cycles.

What is the cost difference between an American and a German boiler?

A German boiler system with an indirect hot water heater and an indoor/ outdoor setback control costs approximately 20% more than an American boiler with an indirect water heater. If you consider the fuel consumption savings, the payback on the additional investment can be as short as one-and-a-half years. If you’d like more information on our German boiler systems, give us a call at 973-383-1421.