A central heating system provides warmth to the whole interior of a building (or portion of a building) from one point to multiple rooms. When combined with other systems in order to control the building climate, the whole system may be an HVAC (heating, ventilation and air conditioning) system.
Central heating differs from space heating in that the heat generation occurs in one place, such as a furnace room in a house or a mechanical room in a large building (though not necessarily at the "central" geometric point). The heat is distributed throughout the building, typically by forced-air through ductwork, by water circulating through pipes, or by steam fed through pipes.
The most common method of heat generation involves the combustion of fossil fuel in a furnace or boiler. Increasingly, buildings utilize solar-powered heat sources, in which case the distribution system normally uses water circulation.
In much of the temperate climate zone, most new housing has come with central heating installed since the Second World War, at least. Such areas normally use gas heaters, district heating, or a oil-fired system, often using forced-air systems. Steam-heating systems, fired by coal, oil or gas, are also used, primarily for larger buildings. Electrical heating systems occur less commonly and are practical only with low-cost electricity or when ground source heat pumps are used. Considering the combined system of central generating plant and electric resistance heating, the overall efficiency will be less than for direct use of fossil fuel for space heating.
Chemical drain cleaner
Chemical drain cleaners can be in solid or liquid form that are readily available through hardware stores, though some (primarily acidic ones) are intended for use by licensed plumbers.1
Alkaline drain openers
Bottles of alkaline drain cleaners containing sodium hydroxide can dissolve greases and hair.
Alkaline drain openers primarily contain sodium hydroxide and some may contain potassium hydroxide. They may appear in liquid or solid form.
Liquid formulations of corrosive alkaline drain cleaners can contain sodium hypochlorite (bleach) and lye (sodium hydroxide or potassium hydroxide) in concentrations up to 50 percent. Other corrosive mixtures come as two-part cleaners that are mixed as they are poured in the drain opening. Inside the drain the two solutions react to release a gas, and surfactants trap the gas as dense foam. The intent of this foaming action is to coat the inside of the drain pipe to dislodge more of the substances that form the clog.
Solid formulations of corrosive alkaline drain cleaners in the form of sodium hydroxide or potassium hydroxide granules can provide more concentrated effective ingredients. Some patented, solid-formula cleaners add aluminum turnings that react with the solid hydroxide in water to heat the caustic mixture to a boil.
Alkaline drain openers can dissolve hair (containing proteins) and fats inside pipes via alkaline hydrolysis of amide and ester respectively:
RCONH2(amide or proteins)+ OH? ? NH3 + RCOO?
RCO2R?(ester or fats)+ OH? ? R'OH + RCOO?
Each of us may be surprised by a sudden increase in bills for consumed water. Then we begin to look for its causes. Establishing such reasons may not be straight, even though access to some of them is made possible by the establishment of independent observations. This is an example where the cause of the suspiciously large bills for consumed water is getting through the washing machine too much water. Then, to improve our household budget can allow repair washing machines made by a plumber. During his visit he may also review the hydraulic in the bathroom, which may help to detect some additional problems. Such a problem can be a water leak.