Boilers that are rated above 90% are called condensing boilers. They are designed to extract heat from the combustion gases that's normally lost in the exhaust lower rated boilers. This energy saving process will only occur under certain conditions. Condensing boilers rely on lower water temperatures of 135 degrees F and lower to gain higher efficiencies. I've seen high efficient rated condensing boilers that were operating at efficiencies in the mid 80% range because the water temperatures were too high to allow the boiler to condense and release the extra heat into the heating system. The best way to ensure low water temperatures are to use a control system also adjusts the water temperature according to the outdoor temperature as well as the indoor temperature. These systems are called weather responsive controls or outdoor reset controls. Not only can it save 15% - 20% on your energy bill but also increases comfort. It provides a constant, steady flow of heat throughout the house with the [b]Steam Water Heater[/b] http://www.maxi-therm.net/steam-to-hot-water/ .
These water heater boiler units are designed to work at temperature levels that are low when they are in the condensing operation. The models that Weil-McLain make available have an outdoor reset as well as a U-Control. This control allows for easy maintenance on the unit as well as creating an ease of installation. They consist of a high grade stainless steel burner. With the variable speed motor, the unit performs much quieter than other models. The comfort level that these Steam Boiler create is unmatched by the consumer.
When searching for a [u]Steam Water Heater Exchanger[/u] unit, you need to make sure that you look at the AFUE ratings that are given because these are the ratings that will tell you how much money you will save on your energy costs. Understanding what the unit does will help the buying process that more easier for the consumer. Heating your home for a good price and getting the comfort that you expect are the key components when looking for a boiler. You may pay more for a unit with a high efficiency rating, but it will more than pay for itself in the long run when you keep getting low energy bills.
The common practice with a [i]instantaneous steam water heater[/i] is to install a easy to use space thermostat. But for better control and extra saving of energy this particular manufacturer has developed their own microprocessor based control system known as Victronic system. In a conventional space heating boiler the temper of water temperature is set at a high temperature by default. One of the outstanding features of the new system is the sensing of outdoor temperature and regulating automatically the optimum indoor temperature by means of boiler water temperature control. Naturally this optimization saves you much on heating bills while making the indoor conditions more comfortable by being precise. In addition, this innovation enables it possible to run boiler at low temperature safely by protecting the heat exchanger from condensation leading to corrosions and numerous other complications. This low temperature feature would significantly contribute to energy saving and environmental protection.