HEATING A BUILDING

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 local 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 most common method of heat generation involves the combustion of fossil fuel in a furnace or boiler. The resultant heat then gets distributed: typically by forced-air through ductwork, by water circulating through pipes, or by steam fed through pipes. 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 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.

Have you ever wondered how people centuries ago heated up their homes, or shall we say, their castles and mansions? Fireplaces were the only means of heating up draughty rooms in those days. You can just imagine the amount of firewood that was used for the past centuries! Today, heating up any structure is a breeze. There is no need to chop up firewood and waste precious trees in order to heat up homes and building.

Heating a building goes hand in hand with ventilating and air-conditioning a structure too. In the USA, HVAC (acronym for heating, ventilating and air-conditioning) is responsible for the heating system of homes and buildings. In the UK the Chartered Institute of Building Services Engineers basically takes care of the heating, ventilating and air-conditioning of buildings. For the purpose of simplification, only the heating system of HVAC will be discussed.

There are different systems of heating up a building. In colder climates, centralized heating is used to heat homes and buildings. This system calls for the use of a furnace, boiler and pump to heat up air, water or steam. The most common types are radiant, forced air, hydronic, geothermal and steam radiant.

Forced-air heating system.

This system is the most common type of heating used in homes. The idea is to heat air in a furnace then forcing the heated air out into vents and ducts installed in various parts of the house. This system is also termed as central heating system as heated air comes from one focal point in the house where it can be humidified, dehumidified and filtered then distributed in the house. The air can be heated up with the use of electricity, propane, gas or oil. This system is inexpensive and convenient as the same system can be used for both heating and cooling. Some of the disadvantages of this system are: the requirement of ducts in walls and ceilings; the furnace could be quite noisy; the moving air could be a source of contamination and allergens; the air requires filtration and maintenance.

Radiant heating system.

This system works through the process of direct heat transfer from a hot to a cold surface. The heat is delivered through a system of hot water tubes underneath the floor or embedded in the ceiling. The water is heated by a broiler powered by electricity or gas or the sun through solar panels. The heat produced by this system is naturally comfortable. However, the system is slow to heat up a house as the water in the tubes has to be heated and circulated first. The hot water tubing is also quite expensive to install and you would need another system for the cooling. In case of breakdown, locating and accessing the problem tubing would be quite hard.

Hydronic heat system.

This heating system is similar to the radiant heat system. The dissimilarity is the placement of the hot water tubes as they are embedded in baseboards attached to the walls of each room in the house. The air is distributed by convection as hot air rises as it is heated by the baseboard fin-tube. This system is highly efficient as temperature for each room can be regulated separately. The system is also expensive because a separate cooling system would be required if the hydronic heat system is used. Some furniture and curtain placement should be considered as the baseboards cannot be obstructed by such. The heating process is slow because of the way the tubes are heated.

Steam radiant heating system.

Think of the old "radiator" unit and you basically get the picture. This system uses either one or two pipes radiator units and heats water by electricity, gas, oil or propane. In the one pipe system, the water and steam travel in one pipe but at opposite direction. In the two-pipe system, steam flows in one pipe while the water returns in the other pipe. This system is efficient and can quickly heat up a room. Old bulky radiators can be replaced with new smaller ones. However, a radiator, no matter how new or small, is still unsightly. The placement of furniture and other decors in a room could also be hindered by such. The air conditioning unit would still need a separate set of ducts.

Geothermal Heating. The geothermal heat pump is the newest way to heat and cool a structure. Heat is taken from one source (the earth) and placed into another (structure). Using the technology of ground loop geothermal system, heat is taken from the earth by the use of ground loop pipe. The system is the most expensive to install but in the long run, it is the most cost effective as it would save you an average of 50% from your heating and cooling bills.

Building a passive solar home is also an option. Passive solar homes are heated (and cooled) directly by the sun. Solar powering a house can either be active or passive. Active solar homes use mechanical equipment like fans and pumps to move and circulate the air inside the house. In passive solar homes, the house is constructed to naturally move air and heat to cool or warm up your house. If you want this type of heating and cooling, then you need to either build a new house or renovate and redesign your house.

You should take into consideration the type of heating system you want in your house. Study the systems presented. Ask professional help if you can't decide what heating system is best for your house. Think of the cooling system that you would install the same time you consider your heating system. Be sure to consider all options including future maintenance expenses including your monthly utility bill. Weigh the advantages and disadvantages of your preferred heating system against the other methods of heating presented to you. Once you have chosen the system that you think is right for you, get some quotes from 2 to 3 contractors.

Different Methods For Heating Buildings The Summer Palace of Peter the Great in St. Petersburg, one of the first buildings to incorporate the modern-type hydrologic central heating

Some buildings in the Roman Empire used central heating systems, conducting air heated by furnaces through empty spaces under the floors and out of pipes in the walls—a system known as a hypocaust.^[1]

In the early medieval Alpine upland, a simpler central heating system where heat travelled through underfloor channels from the furnace room replaced the Roman hypocaust at some places. In Reichenau Abbey a network of interconnected underfloor channels heated the 300 m² large assembly room of the monks during the winter months. The degree of efficiency of the system has been calculated at 90%.^[2]

In the 13th century, the Cistercian monks revived central heating in Christian Europe using river diversions combined with indoor wood-fired furnaces. The well-preserved Royal Monastery of Our Lady of the Wheel (founded 1202) on the Ebro River in the Aragon region of Spain provides an excellent example of such an application.

The Roman hypocaust continued to be used on a smaller scale during late Antiquity and by the Umayyad caliphate, while later Muslim builder employed a simpler system of underfloor pipes.^[3]

By about 1700 Russian engineers had started designing hydrologically based systems for central heating. The Summer Palace (1710–1714) of Peter the Great in Saint Petersburg provides the best extant example. Slightly later, in 1716, came the first use of water in Sweden to distribute heat in buildings. Martin Triewald, a Swedish engineer, used this method for a greenhouse at Newcastle upon Tyne. Jean Simon Bonnemain (1743–1830), a French architect,^[4] introduced the technique to industry on a cooperative, at Château du Pêcq, near Paris.

Angier March Perkins developed and installed some of the earliest steam-heating systems in the 1830s. The first was installed in the home of Governor of the Bank of England John Horley Palmer so that he could grow grapes in England's cold climate.^[5]

Franz San Galli, a Polish-born Russian businessman living in St. Petersburg, invented the radiator between 1855–1857, which was a major step in the final shaping of modern central heating.^[6][7]