Residential boilers

See also Air Conditioning Building Design, Commercial Building Design, Residential Furnances and Boilers. 

Tn the early to mid-1980s, retail gas prices began to rise as the more expensive new gas constituted an increasing percentage of the pipelines average cost of gas. This drove consumer prices above the level that would exist in a competitive market, and demand for natural gas was subsequently reduced as large industrial customers switched to other fuels. Also reducing demand were the Fuel Use Act, which prohibited the use of natural gas as a boiler fuel, increased consen a-tion by residential and commercial customers, warnier-than-normal winters, and an economic recession. 

Finally, if the boiler house is to be within an industrial complex and there is no adjacent residential development, the building need only be suitable for adequate weatherproofing of the plant and for maintenance. Alternatively, if it is sited adjacent or near to housing or offices then the building structure should take account of this. 

The use of sensors for surveillance of industrial combustion processes is state of the art. Especially optical sensors detect the existence of a flame. With decreasing furnace performance the amount of installed sensors declines. In residential appliances there are nearly no sensors installed because the costs for both, sensors and actuators, have to be balanced with the technical profit. The efforts for setting up combustion controls are very ambitious but in many cases not successful. First a distinction has to be made between sealed boilers and those that are open towards the room in which they are installed. The resulting controls cannot be interchanged between these two groups of appliances. 

When hydrogen is burned in a combustion chamber instead of a conventional boiler, high-pressure superheated steam can be generated and fed directly into a turbine. This could cut the capital cost of a power plant by one half. While hydrogen is burned, there is essentially no pollution. Expensive pollution control systems, which can be almost one third of the capital costs of conventional fossil fuel power plants are not required. This should also allow plants to be located closer to residential and commercial loads, reducing power transmission costs and line losses. 

Smaller fuel cells (<20 kW, but more typically <5 kW) are being developed for residential applications, particularly in Japan and Europe. These fuel cells use natural gas as fuel (therefore they are equipped with a reformer). Most often they also enable capture and utilization of waste heat and use it for space and/or hot water heating in combination with a natural gas boiler, resulting in high overall efficiency. 

Type test standards (CEN/TC 295) for residential solid fuel burning appliances with < 50 kW are presently under evaluation in the European Community (EC). The draft standards of the Comite de Normatimtion (CEN) cover the type tests for determination of efficiency and emissions of solid fuel burning appliances, such as cookers, single room heaters, inserts and boilers. 

There are millions of combustion sources in the United States. Residential heating units burn oil, gas, coal and wood for heat. Larger commercial, institutional, and utility boilers burn fossil fuels to generate heat and electricity. Many industrial processes involve the combustion of fuels and other raw or waste materials to produce heat and/or recover products of marketable value. 

However, despite all the progress being made, the uncontrolled production unavoidably leads to environmental problems such as climate change or emission of toxic products. For example, dioxins and furans are unintentionally formed and released from various sources like open burning of waste, thermal processes in the metallurgical industry, residential combustion sources, motor vehicles, particularly those burning leaded gasoline, fossil fuel-fired utility and industrial boilers, waste oil refineries etc... 

Annual Fuel Utilization Efficiency (AFUE) - The measure of seasonal or annual efficiency of a residential heating furnace or boiler. It takes into account the cyclic on/off operation and associated energy losses of the heating unit as it responds to changes in the load, which in turn is affected by changes in weather and occupant controls. 

---