Introduction
Central heating systems are important in the hospitality industry since residents rely on such systems to keep warm during winter or other cold seasons (Oreszczyn, Hong, Ridley, and Wilkinson 259). These systems ensure that residents enjoy a comfortable environment as they relax, dine or sleep.
Heating entails the raising of the temperature of an area (building) for the sole reason of maintaining a comfortable environment. For efficient heating, buildings must be structured in certain ways and the electrical and mechanical systems examined.
Some of the earliest methods of heating buildings included the use of an open fire. Other sources include the use of a fireplace and cast-iron stoves. With time, modern space heaters have been developed. All these sources are referred to as direct heating processes.
This is due to the fact that energy conversion to heat takes place at the area of heating. A more recent technology in heating is referred to as central (indirect) heating. This is whereby energy is converted to heat at a different location and transferred to the site where heat is required. The heat may be transferred through different mediums including steam, air or water.
Central heating was also considered useful due to the increase in size of buildings and industries (such as the hospitality industry). The hospitality industry is characterised by large buildings (hotels and restaurants). Therefore, this calls for the use of a central heating system in order to ensure efficiency in heating of the entire space.
The hotel and hospitality industry is keen at ensuring customer satisfaction, which calls for the need for a comfortable environment within the accommodation and dining areas (Humphreys 132). Advancements have been seen in the central heating systems.
Cost-effective methods have been introduced with time in order to ensure that the heating systems do not contribute to huge costs since businesses are meant to minimize costs as much as possible. This paper will discuss the trends in the central heating systems in the hospitality industry.
Components of Central Heating Systems and Fuels Used
The main components of a central heating system include the source of heat and appliances for heating, medium of conveying the heat (ducts or pipes) to the area where heating is required, and spaces for releasing heat. Heat may be released through radiation, convection or both. The use of forced-air distribution involves moving heated air through the building using fans.
This method uses pressure differentials in order to force air in areas of low pressure. Another method of transferring heat is through radiant heating. Heat is transmitted to the surfaces of the building.
These include the ceilings, floors and walls. This causes a convection cycle of heat around the space and causes uniform heating of the air in the building. Radiant heating is advantageous in that it does not involve any visible heating equipment.
There are several factors to consider while designing a central heating system. Some of them include the following:
- Relative humidity
- Amount of physical activity in the area
- Convection
- Effects of solar radiation
The amount of physical activity in an area is also a consideration while setting up heating systems because the human body usually gives off heat energy. Individuals performing strenuous work dissipate a lot of heat. Therefore, the heating system should be designed in such a way that rooms with heavy human activity should not be heated as much as those that do not contain heavy activity.
The hotel setting is made up of different areas with different human activities. Rooms with heavy activity include the kitchen areas. Heat should be kept at about 13 degrees Celsius in order to allow the extra heat from the bodies to be dissipated. Other rooms with less activity should be kept at about 24 degrees. These areas include the domestic living rooms or where sedentary workers stay.
Fuels may also be used to produce heat. This involves the production of energy from a reaction between hydrogen and carbon in the presence of oxygen. When heat is produced, it is transferred through water or air as mediums. This systems work through circulation.
This is whereby the heated medium is constantly replaced. The equipment used depends on the medium to be used. When air is used, the combustion chamber is referred to as a furnace. On the other hand, if water is to be used, the combustion chamber is a boiler. The main fuels used in the above case are fuel oils and gas.
Air Heating
Air heating is one of the ways of providing heat in hotels and restaurants. However, air can only carry limited heat for shorter distances as compared to steam and water. This is due to the fact that it has a low density. In these systems, heat is transferred from the furnaces. It passes through air ducts to the rooms in the building. The warm air is released through registers into the open spaces.
Since warm air is lighter than cool air, warm air rise into the ducts and is transferred to the rooms. The hot air can also be motor-driven by fans. This way, hot air can be forced through smaller air vents and for longer distances. This is especially applicable in large hotels and restaurants that consist of many rooms that require warming.
Water Heating
The use of water as a medium for heating in a central heating system is favoured. It is preferred due to the properties of water (high density). This implies that it can hold more heat energy and the temperatures may be easily regulated (Shipworth, Firth, Gentry, Wright, Shipworth, and Lomas 53). The hot water from the boiler is transferred through a series of copper or steel pipes to the areas that require heating.
These metals allow heat to be dissipated into the building (rooms). As water becomes cooler, it is redirected for reheating. The cycle then continues.
The hot water is forced through the pipes in the building using a pump driven by motors. This implies that the boilers may be placed at any elevation since water would be pumped up. There are two factors that must be considered while constructing a hot water system. They include the following:
- Allowance for expansion of the water
- Provision to allow air to escape through valves
Hydronic Heating
One of the trends in the central heating systems is the use of hydronic heating. This process involves the heating and circulation of water throughout the building. They may also be circulated under floor heating coils. In this case, heat is transmitted using water as a medium. Various ways can be used to heat this water. Examples include the use of electricity, gas or solar.
The heat source may be situated inside or outside the building. As heat from the hot water is dissipated, the water is circulated back for reheating. This is done until the desired room temperature is attained.
The use of hydronic heating for central heating is effective since it ensures that each room within the building is heated to comfortable and desired temperature (Shipworth 14). The control panel is usually placed at an area that is easy to access in order to ensure that the temperature is easily adjusted.
Choosing this kind of central heating system is valid when one needs to cut on costs. Installation of the hydronic central heating system may be expensive but is worth the price. It offers efficient service and the running costs are reduced and manageable. Hydronic central heating also provides radiant heating. This means that radiant heat is used to warm the rooms.
This is as opposed to the use of warm air for heating. Radiant heating ensures that even the objects and individuals in the room are heated. The heated objects may then transmit the heat. Since these objects remain warm for a long time, the house is kept warm for longer. The other methods of using push fan for heating is not effective since it forces warm air through the building and only warms the air.
The objects in the building remain cool. Therefore, this implies that there is immediate loss of heat from the building. This also means that such a heating system must remain operational for a longer time in order to keep the building warm. Using a fan to force air also contributes to loss of heat.
Air pressure in the building is increased. Therefore, the air path is affected and this implies that the air may not be able to flow back for reheating. For this reason, operational costs are increased. Therefore, hydronic heating provides a cost-effective choice for central heating in the hospitality industry.
Steam Heating
This system uses steam for heating. Steam is usually generated in the boiler and transferred through pipes just as hot water is transferred. Steam heats the radiators and causes the heating of the rooms within the building. As the steam gives off its heat it cools (condenses) to form water.
Water is then returned to the boiler. This may be done using gravity or using motor-driven pumps. Each radiator must have valves that allow air to escape. This is necessary since steam may not be able to enter the radiators. However, this system is not preferred in many hotels and restaurants today because it is bulky and unattractive.
Electric Heating
One of the widely used heating systems today is electric heating. This method involves the passing of an electric current through resistors. When this is done, heat is generated. These resistors may heat water or air. When air is heated in a room, warm currents circulate the room causing uniform heating.
Electricity may also be used to generate heat using heat pumps. This involves pumping heat from a cooler area to an area of higher temperature. The equipment used is a refrigerant. It is used to pump heat from sources with low temperature to spaces that require heating. Such refrigerants double as air conditioners during summer and heat pumps during winter.
Gas for central heating systems
Gas is one of the cost effective fuels used for central heating in large buildings such as office complexes, hotels and restaurants. The use of gas is also considered environmentally friendly since it does not produce carbon emissions (Hossein 1304). It is usually a clean fuel that is tidy in nature since it does not produce ashes or smoke as compared to coal and other fuels.
The use of gas for central heating may be seen as cost-effective when compared to the use of electricity. Its cost-effectiveness is realized if gas is used in a large scale. Therefore, this choice may be applicable for central heating in large hotels and restaurants.
Dual Fuel Systems
As the name suggests, the dual fuel system uses two sources of energy. Its operation resembles the hybrid vehicles that use both electricity and gasoline to operate. When the vehicle is under light driving conditions, electricity is utilized. However, the fuel engine must take over when more horsepower is needed.
The dual system operates using electricity during mild weather. However, at very low environmental temperatures, the use of electricity may become less cost-effective. Therefore, the use of oil or gas is automatically started.
The heat pump is similar to a refrigerant but operates in the opposite direction. This implies that instead of cooling the air, it provides warmth. The traditional heat pumps loose efficiency when the outdoor air temperature drops significantly.
In fact, it has been argued that it is among the least cost effective when compared to other sources of energy (gas, propane, oil). However, new breeds of heat pumps have been developed so as to increase efficiency even at temperatures below zero (Ljubenko, Poredos, Morosuk, and Tsatsaronis 1303).
Green Solutions in Central Heating Systems
Due to the rise in gas and oil prices, there has been a need to use alternative energy sources for central heating systems. Climate change is also a concern when it comes to the type of fuel used and this has forced the need for green solutions.
One of the major efforts has been to cut the use of fossil fuels to a minimum. Water heating in buildings is widely used around the globe. Efforts towards energy conservation and the use of renewable energy sources would go a long way in saving on costs and ensuring that climate change is curbed (Groscurth and Brauer 2511). The hotel and hospitality industry needs to embark on the solar age.
Solar Thermal Heating
This system is currently widely used. This means that this technology has matured and has been embraced. It is among the fastest growing renewable technologies and is widely accepted by conservationists since it is friendly to the environment (Steg 4450). This is so since there is no emission of greenhouse gases. Other fuels are non-renewable and may be over-used. This is why the use of solar energy is the way to go.
The sun provides free energy that can be used to produce energy necessary for heating water and providing heating for open spaces in buildings. The choice of solar heating is also favoured by the government due to the ever-increasing costs of fuels. Therefore, solar heating is a form of return on investments. Solar heating can be use for the following:
- Heating water
- Supplementing space heating in buildings
- Generating heat for air conditioning systems in buildings
Hotels and restaurants may employ the use of solar thermal heating. It is also important as a marketing strategy for environmentally conscious individuals. Hotels that have swimming pools may also benefit from solar heating to heat the water.
Heating of pool water is usually done using the surplus heat from the energy used to heat the building. Therefore, this means that the pool water is heated at no extra cost. This also means that the heat energy is not wasted. This implies that this venture is cost effective.
Just like any other large building, hotels and restaurants often require huge air conditioning systems. Solar thermal energy may be used to provide heat for such conditioning systems (Duffie, and Beckam 11).
Components of solar thermal heating system
The main components of the solar heating system include the solar collectors and the storage tanks. The roofs of the buildings are usually mounted with solar collectors in order to capture direct or indirect sunlight (Lindenberg, Bruckner, Groscurth, and Kummel 602). After being heated, the water is transferred into storage tanks. Heat storage may be in the form of short-term storage or seasonal storage.
Short-term storage involves storing heat to be used for a short period of time. This may be during the rainy season, for example. Seasonal storage is storage of captured solar heat over a period of several weeks. This is usually applicable where there are a large number of occupants in a building. Therefore, this may be applicable in the hospitality industry where accommodation is provided.
Another type of storage is the borehole heat storage. This is whereby solar-heated water is transferred underground using boreholes. Since soils have low thermal capacity, heat can be retained. The aquifer heat storage is another type of storage system that is cost-effective.
This is whereby groundwater is used to store heat. However, this system may only be adopted in areas with specific hydrogeological conditions. Solar heating may be used for both centralized and decentralized heating systems. For central heating, the four or two-pipe system may be employed.
The advantages and cost-effectiveness of using solar energy for central heating may be seen in three ways as follows:
- Energy output
- Capital costs
- Trends in oil prices – With the increase in oil and gas prices, solar heating becomes a cost-effective choice for central heating
Conclusion
Central heating systems are very useful in the hospitality industry since comfort is a priority for the residents. This is mainly applicable during winter or during cold weather. Central heating systems provide heating of the interior in order to make the conditions conducive for inhabitants. The heating system has evolved with time. Long time ago, open fires were used for direct heating.
Some of the early heating methods that may still be in use today include the use of the fireplaces. However, direct heating does not apply for large areas. For large areas such as hotels and restaurants in the hospitality industry, central heating systems are adopted.
This involves heating of a medium and transferring heat to a destination far from the heat source in order to provide heating. Sources of energy for central heating include oil, gas, electricity and solar energy. Some of these sources are more cost-effective while others provide more heat energy than others do. The suitable central heating system should be installed to suit the needs of the building and its inhabitants.
Works Cited
Duffie, John, and William Beckam. Solar engineering of thermal processes. New York: Wiley, 1980. Print.
Groscurth, Hamburg, and Wien Brauer. “Support of renewable energy sources in liberalized electricity markets.” Energy 16.1 (1998): 2505-16. Print.
Hossein, zolfagharyazizi. “Environment pollution and the future prospects of central heating systems.” Australian Journal of Basic and Applied Sciences 5.12 (2011): 1303-1306. Print.
Humphreys, Mike. Thermal comfort temperatures and the habits of hobbits. London: E & FN Spon, 1995. Print.
Lindenberg, Daniel, Thomas Bruckner, Henry Groscurth, and Reiner Kummel. “Optimization of solar district heating systems: Seasonal storage, heat pumps and cogeneration.” Energy 25.1 (2000): 591-608. Print.
Ljubenko, Andrej, Alojz Poredos, Tatiana Morosuk, and George Tsatsaronis. “Performance analysis of a district heating system.” Energies 6.1 (2013): 1298-1313. Print.
Oreszczyn, Tadj, Sung Hong, Ian Ridley, and Paul Wilkinson. “Determinants of winter indoor temperatures in low income households in England.” Energy and Buildings 38.1 (2006): 245-252. Print.
Shipworth, Michelle. Motivating home energy action: A handbook of what works. Canberra: Australian Greenhouse Office, 2000. Print.
Shipworth, Michelle, Steven Firth, Michael Gentry, Andrew Wright, David Shipworth, and Kevin Lomas. “Central heating thermostat settings and timing: Building demographics.” Building Research & Information 38(1): 50-69. Print.
Steg, Lern. “Promoting household energy conservation.” Energy Policy 36.1 (2008): 4449-4453. Print.