How does the heating system work

heating

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heating, process and system of raising the temperature of an enclosed space for the primary purpose of ensuring the comfort of the occupants. By regulating the ambient temperature, heating also serves to maintain a building’s structural, mechanical, and electrical systems.

Historical development

The earliest method of providing interior heating was an open fire. Such a source, along with related methods such as fireplaces, cast-iron stoves, and modern space heaters fueled by gas or electricity, is known as direct heating because the conversion of energy into heat takes place at the site to be heated. A more common form of heating in modern times is known as central, or indirect, heating. It consists of the conversion of energy to heat at a source outside of, apart from, or located within the site or sites to be heated; the resulting heat is conveyed to the site through a fluid medium such as air, water, or steam.

Except for the ancient Greeks and Romans, most cultures relied upon direct-heating methods. Wood was the earliest fuel used, though in places where only moderate warmth was needed, such as China, Japan, and the Mediterranean, charcoal (made from wood) was used because it produced much less smoke. The flue, or chimney, which was first a simple aperture in the centre of the roof and later rose directly from the fireplace, had appeared in Europe by the 13th century and effectively eliminated the fire’s smoke and fumes from the living space. Enclosed stoves appear to have been used first by the Chinese about 600 bc and eventually spread through Russia into northern Europe and from there to the Americas, where Benjamin Franklin in 1744 invented an improved design known as the Franklin stove. Stoves are far less wasteful of heat than fireplaces because the heat of the fire is absorbed by the stove walls, which heat the air in the room, rather than passing up the chimney in the form of hot combustion gases.

Central heating appears to have been invented in ancient Greece, but it was the Romans who became the supreme heating engineers of the ancient world with their hypocaust system. In many Roman buildings, mosaic tile floors were supported by columns below, which created air spaces, or ducts. At a site central to all the rooms to be heated, charcoal, brushwood, and, in Britain, coal were burned, and the hot gases traveled beneath the floors, warming them in the process. The hypocaust system disappeared with the decline of the Roman Empire, however, and central heating was not reintroduced until some 1,500 years later.

Central heating was adopted for use again in the early 19th century when the Industrial Revolution caused an increase in the size of buildings for industry, residential use, and services. The use of steam as a source of power offered a new way to heat factories and mills, with the steam conveyed in pipes. Coal-fired boilers delivered hot steam to rooms by means of standing radiators. Steam heating long predominated in the North American continent because of its very cold winters. The advantages of hot water, which has a lower surface temperature and milder general effect than steam, began to be recognized about 1830. Twentieth-century central-heating systems generally use warm air or hot water for heat conveyance. Ducted warm air has supplanted steam in most newly built American homes and offices, but in Great Britain and much of the European continent, hot water succeeded steam as the favoured method of heating; ducted warm air has never been popular there. Most other countries have adopted either the American or European preference in heating methods.

Central-heating systems and fuels

The essential components of a central-heating system are an appliance in which fuel may be burned to generate heat; a medium conveyed in pipes or ducts for transferring the heat to the spaces to be heated; and an emitting apparatus in those spaces for releasing the heat either by convection or radiation or both. Forced-air distribution moves heated air into the space by a system of ducts and fans that produce pressure differentials. Radiant heating, by contrast, involves the direct transmission of heat from an emitter to the walls, ceiling, or floor of an enclosed space independent of the air temperature between them; the emitted heat sets up a convection cycle throughout the space, producing a uniformly warmed temperture within it.

Air temperature and the effects of solar radiation, relative humidity, and convection all influence the design of a heating system. An equally important consideration is the amount of physical activity that is anticipated in a particular setting. In a work atmosphere in which strenuous activity is the norm, the human body gives off more heat. In compensation, the air temperature is kept lower in order to allow the extra body heat to dissipate. An upper temperature limit of 24° C (75° F) is appropriate for sedentary workers and domestic living rooms, while a lower temperature limit of 13° C (55° F) is appropriate for persons doing heavy manual work.

Heating and Cooling System Basics

Most of us take heating and cooling for granted. We expect our heating systems to keep us warm during the winter, and we depend on air-conditioning to keep us cool during the summer.

When the house is cold in winter or hot in summer, the natural reaction is to call for professional service. Fortunately, there is an alternative. You can cut service costs drastically and keep your heating and cooling systems working efficiently by doing some maintenance and quick fixes yourself. But first, it’s important to know how the basics of how heating and cooling systems function.

How Heating and Cooling Systems Work

All climate-control devices or systems have three basic components: a source of warmed or cooled air, a means of distributing the air to the rooms being heated or cooled, and a control used to regulate the system (e.g., thermostat). The sources of warm air, such as a furnace, and cool air, such as an air conditioner, in a house often use the same distribution and control systems. If your house has central air conditioning, cool air probably flows through the same ducts that heat does and is regulated by the same thermostat. When a heating or cooling system malfunctions, any of these three basic components may be causing the problem.

Both heating and air conditioning work on the principle that heat always moves from a warm object to a cooler one, just as water flows from a higher to a lower level. Furnaces and heaters put heat into the air to make your home warmer; air conditioners remove heat to make your home cooler.

When the furnace is turned on, it consumes the fuel that powers it, whether it be gas, oil, or electricity. As fuel is burned, heat is produced and channeled to the living areas of your home through ducts, pipes, or wires and then is blown out of registers, radiators, or heating panels. Older systems use the heat they produce to heat water, which in turn heats the air in your home. These systems use a boiler to store and heat the water supply, which is then circulated as hot water through pipes embedded in the wall, floor, or ceiling.

In the next section, we’ll review the different distribution systems used for heating and cooling the home.

Understanding HVAC: How Heating and Cooling Systems Work

Few things are more refreshing than stepping into an air conditioned room on a hot, summer’s day. But just what exactly is happening inside your home to keep it cool?

A building’s air conditioning is part of a larger system commonly referred to as its heating, ventilation, and air conditioning system (or HVAC for short). Your home’s HVAC system is essentially an expansive machine consisting of a ventilation system, thermostat, and various devices that either heat or cool the air.

Understanding the basics of how this system functions can be very helpful when deciding to repair or replace it. This article explains in layman’s terms what’s occurring behind the scenes to keep your home cool in the summer and warm in the winter.

V for Ventilation

The ventilation portion of your HVAC system is made up of return and supply vents (also sometimes called registers), ductwork, filters, and a circulating fan. The circulating fan pulls air from inside your home through the return vents, into the ductwork, and over the devices that either heat or cool the air. Then it pushes that air back into the rooms of your home through the supply vents.

This system, known as a forced air system, is the basis for the heating and cooling of your home. Before going into detail regarding the actual heating and cooling processes, however, a very brief physics lesson is in order.

HVAC Physics

There are two key principles of physics that all HVAC systems depend on for proper functioning:

Now let’s apply these principles to a residential HVAC system.

Air Conditioning Systems

The air conditioning component of most residential HVAC systems is a split system, so called because the system’s work is split between an outdoor unit (the compressor and condenser) and an indoor one (an evaporator coil).

Connecting the two is copper tubing through which runs a refrigerant. This refrigerant is chemically designed to be capable of vaporizing at moderate temperatures, which is crucial to the functioning of the system.

The refrigerant begins the cooling cycle in the compressor as a cool, low-pressure gas. The compressor compacts that into a hot, high-pressure gas, which is then piped through the condenser where it condenses into a cooler, high-pressure liquid as a fan blows the excess heat into the air outside your home. Because the refrigerant was pressurized in the compressor, its boiling point has increased, allowing it to stay in its liquid form.

From there, the refrigerant is seeped into the indoor evaporator coil, which is often attached to the furnace. This is where the magic happens. Once in the coil, the refrigerant is allowed to expand, thus reducing its pressure and, consequently, its boiling point. This causes the liquid refrigerant to vaporize into a gas, a process that absorbs heat from the surrounding air.

That air, now much cooler, is then blown by a fan through your ductwork and into the rooms of your home.

Finally, the low-pressure gas is returned to the compressor to begin the cycle all over again until the thermostat senses that your home has reached the desired temperature.

Heating Systems

While there is more diversity in residential heating systems than in their A/C counterparts, the basic premise is the same. Air is drawn into the HVAC system’s ductwork, heated, and then recirculated throughout the home. The greater diversity lies in how that air is heated.

Some systems, like heat pumps, are basically air conditioning systems reversed. In fact, heat pumps are able to both heat and cool, simply by reversing the hot and cold coils. When in air conditioning mode, the heat pump works as described above. When in heating mode, the hot and cold coils are reversed and the heat pump pulls in air from outdoors, essentially transporting the heat into your home. Some heat pumps even draw in heat from underground.

Other systems, such as a furnace system, burn some kind of fuel (like oil or natural gas) to heat the air.

Heat Pumps vs. Furnaces and Central A/C Units

Many homeowners struggle over whether they should use a heat pump or a combination furnace and central air conditioner for their heating and cooling needs.

Heat pump advantages:

Furnace and central A/C advantages:

Most experts say that if your weather rarely reaches near-freezing temperatures, you should probably go with a heat pump. If you live in a climate where the winters are long and cold, however, a furnace and central air system is probably your best bet.

Hybrid heating and cooling systems

In addition to the above two options, a third, hybrid system has emerged in recent years and is rapidly becoming a common choice among homeowners. A hybrid system is a heating system that incorporates both a furnace and a heat pump, utilizing one or the other depending on the outdoor temperature.

The system calculates the temperature at which it would be more economical to use either the furnace or the heat pump (called the economic balancing point), and switches between the two as the temperature moves above or below that point. A hybrid system may be best for you, depending on your climate. Talk to a professional HVAC contractor to aid in evaluating your options.

Contact an HVAC Professional

Now that you have a general understanding of how HVAC systems work, you can be more confident in identifying when and where problems occur. You can also be more confident when talking to an HVAC contractor or deliberating between various options.

That said, remember that HVAC systems are complicated machines that utilize potentially hazardous chemicals. Just as you wouldn’t start tinkering with your vehicle’s engine without advanced knowledge, don’t attempt to make HVAC repairs unless you have received adequate training.

Did you find this article helpful? Check out the three things every homeowner should know about HVAC.

How does the heating and cooling system work in a house?

HVAC system, also known as the heating, ventilation, and cooling system, is one of the major requirements in every house. The HVAC system is equipped to work as a cooling and heating system. Hence, there won’t be any need to get an air conditioner and a room heater separately for different seasons.

However, most people think that the HVAC system is only suitable for commercial places like malls, offices, large buildings, theatres, auditoriums, etc. What they don’t know is that now, the heating and cooling system is available for residential places as well. Yes, there are several differences in the residential HVAC systems as compared to the commercial ones, but the operation of the appliance is the same- heating the rooms during the colder season and cooling the area in the summers.

If you aren’t aware of the HVAC systems in detail, do not worry any further. The forthcoming article will describe the basic facts you need to know about the cooling and heating systems for residential purposes.

What are the two major parts of the HVAC system?

A residential HVAC system can be divided into two major parts: the heating and cooling systems. Each part will have its component through which the temperature inside your house will be controlled. Before you learn about the working of the heating and cooling system, we first need to focus on the different parts of the HVAC system combined.

Working on the HVAC system?

It will be easier to understand its working since you are now aware of the major components present in the heating and cooling system.

Conclusion

Installing an energy-efficient HVAC system in your home will reduce your overall power consumption. So, if you want to control the interior temperature for comfort, you need to install the best heating and cooling system at the earliest.

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I am Amelia Varley, a qualified blogger. Here you can see my skills which give you small ideas on understanding all the concepts with different themes. I love to write a blog on different topics, like health, home décor, Automotive, Business, Food, Lifestyle, Finance, Flowers, etc.

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How Central Heating Works

November 25, 2020

How do central heating systems work? The diagrams and descriptions in this section define central heating and air conditioning, forced-air furnaces, as well as radiant heating systems.

A central heating system has a primary heating appliance such as a furnace or boiler located in an out-of-the-way place such as a basement or garage. It delivers heat throughout the house either by pumping warmed air through a system of air ducts or sending hot water or steam through pipes to room radiators or convectors.

With both forced-air and gravity systems, one or more thermostats turn the heating or cooling unit off and on as room temperatures rise and fall. Homes without central heating normally utilize electric baseboard heaters or, in some cases, in-wall or in-floor gas heaters or radiant heat.

In contemporary homes, ducted air systems are the most common type of central heating and cooling. If your home has an air conditioner, heat pump, or furnace, it is a ducted air system. There are two main types: forced-air and gravity.

With a forced-air system, a furnace warms air, an air conditioner cools air, a heat pump either warms or cools air, and then a blower forces the heated or cooled air through the system and out into the living spaces.

With a gravity furnace, convection currents (caused by the natural tendency of hot air to rise) carry heated air through the system from a furnace located on or below the main floor. Gravity systems do not have blowers, tend to have very large air ducts, and can only deliver warmed air.

If your system includes an air conditioner or heat pump, it is a forced-air system. With these, cooled (and sometimes humidified or electronically cleaned) air is usually delivered through the same duct work and registers employed by heated air. An air conditioner runs on electricity and removes heat from air with basic refrigeration principles.

A heat pump can provide both heating and cooling. In the winter, a heat pump extracts heat from outside air and delivers it indoors.

On hot summer days, it works in reverse, extracting heat from room air and pumping it outdoors.

Like air conditioners, nearly all heat pumps are powered by electricity.

They have an outdoor compressor/condenser unit that is connected by refrigerant-filled tubing to an indoor air handler. As the refrigerant moves through the system, it completes a basic refrigeration cycle, warming or cooling the coils inside the air handler.

The blower pulls in room air, circulates it across the coils, and pushes the air back into rooms through duct work. When extra heat is needed on particularly cold days, supplemental electric-resistance elements kick on inside the air handler to add warmth to the air passing through it.

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