Ventilation is the mechanical system in a building that brings in "fresh" outdoor air and removes the "contaminated" indoor air and to maintain indoor air quality for the humans.In a workplace, ventilation is used to control exposure to airborne contaminants. Ventilation is needed to provide oxygen for metabolism and to dilute metabolic pollutants (carbon dioxide and odour) and pollutant from the structures and furniture. When, there are combustion appliances such as gas heaters inside indoor spaces with peoples, the spaces should be ventilated to provide oxygen to combustion appliances.
Ventilation improves indoor air quality (IAQ) through mechanical means, such as through outdoor air intakes associated with the Heating, ventilation and air conditioning (HVAC) system and filtration.
Nowadays, the ventilation exhaust systems are combined with fresh air supply systems into a Heat/Energy Recovery system (ERU) so part of the cooling or heating energy contained in the exhausted air to be recovered and to be used in the pre-treatment of the fresh air supplied to the building.
A space heating system is a system that uses primary energy from hydrocarbon fuels or electricity or energy renewable sources such as wood pellets or from solar or a geothermal system to heat a room, a house, block of apartment houses, offices or hotels etc.Space heaters are powered by electricity or a burnable fuel, such as natural gas, propane, fuel oil, or wood pellets. In the Northern Europe, the air conditioning systems for dwellings are solo heating ones as the cooling is not required.
However, in Southern Europe, the air conditioning systems must do both heating and cooling or to use one system for space cooling and another for space heating. In the past, heating of duelling was affected with radiators. Heating water produced by a boiler/ gas or gasoil burner system is circulated through the radiators which are heating the space by radiator and air convection.The most popular heating system is a radiant floor system and it can be affected with electrical resistance wires or with hydronic piped floors. The most environmental friendly is the one that utilizes a heat pump heater which produces heating water by pumping the energy from the surrounding air. The technology of heat pump has developed so much that heat pump can pump energy even at ambient temperatures of -15 0C with a good efficiency. The heated floor radiates the heat to the space without any movement of the air.
In buildings, domestic hot water is required for sanitation in showers, baths, sinks and in kitchens for food preparation. Production of Hot water is an energy intensive process and different systems are employed depending on the application and budget.
Electric Resistors: A widely used method is the used of electric resistors. Industrial products built for the specific purpose are widely available in the market known as instant heaters, cylinder heaters etc. The used of electric heaters is usually limited to the production of hot water in isolated taps installed usually under counter tops in offices or small shops.
Direct or indirect fired Gas or Gasoil Cylinder heaters: Hydrocarbon fuels are burned in a boiler and hot water can be produced. The method is widely used in domestic and commercial applications especially where there is supply of natural gas and where due to the inclined weather ( very low ambient temperatures below -5 0C are present) and the use of renewables sporces such as solar or heat pumps is not effective.
High temperature Heat Pumps ( 60-65 0C): Nowdays, due to the evolution of the HP technologies and due to the EC’s compulsory directives and regulations, the heat pumps are widely used to prepare domestic hot water since are considered renewable sources and enviromental friendly with smaller energy foot print ( lower CO2 emissions). The ranges of available HP is very wide so the Hps are used both in residential, commercial and industrial applications. It is worth mentioning that due to the increasing cost of electricity or the cost of hydrocarbon fuels, heat recovery systems have become popular. For instance, a water chiller can be supplied with a desuperheater heat exchanger which gives the user the possibility to utilize the otherwise rejected to the environment heat to warm up water. In the market,there are heat pumps that can recover 100%the condensing heat of the refrigeration cycle through a water circuit. These heat pumps are called multipurpose or 4 pipe chillers etc. The multipurpose heat pump which can produce simultaneously and independently cooling or heating watetr are becoming popular in the hotel industry where the demand for domestic hot water is a prime expense.
Solar Systems: The used of solar systems for the production of hot water has become a must especially in the EC countries. In Cyprus, there is long tradition for solar systems since they have being widely used since the 70’s ; Once, Cyprus was a leader & pionner in the production and use of thermosiphon type solar heaters. Nowdays, the use of solar heater in the residential sector has been a standard choice dictated by the need to reduce CO2 emissions whereas in the hotel industry is obligatory as a term of the built permit.
Modern buildings cannot be inhabited or use without running cold and hot water services. The water is used in toilets, basins, sinks, showers, baths , dish washers and in clothes’ washing machines. In any catering or food processing water is needed in food preparation but for cleaning and sanitizing.
Usually, the fresh water from city mains is stored in plastic in tanks and then is pumped by a booster pump to the sanitary fittings.
The pipe distribution networks are made of a diverse type of materials. In the past copper pipe materials were dominating the sector but nowadays because of the development in the technology of plastics and the fact that plastics are more economical, plastic pipe materials are mostly used such as:
The dirty soiled water from the toilets, wash basins, sinks, showers and other points of use inside the building are drained out to the sewer through a network of pipes either by gravity or with the aid of pumps.
In the past, the material used to build soiled water networks was galvanized iron or cast iron when reduced noise properties were sought. Nowadays, plastics pipes are mostly used either plain or in composite form such as: UPVC, Polypropylene (PP), polypropylene mineral composites (PP-MD).
The composite plastic pipes are pipes that have been designed to reduce the noise generated during the flow of liquids and emitted to the surrounding areas. Noise is important in certain application and nearly silent pipes are available in the market.
A swimming pool, swimming bath, wading pool, paddling pool, or simply pool is a structure designed to hold water to enable swimming or other leisure activities. In simple form, the mechanical system of a swimming pool consists of a circulating pump which draws water from main drains and skimmer overflow fittings/perimeter overflow channel, pasts it through a sand filter, through a chlorinator or other water treatment device and delivers it to the inlet nozzles inside the pool.
The Water in a swimming pool must be kept in circulation for many hours so the dirt and debris is removed and the bacteria and other pathogen microorganisms are destroyed when in contact to the chemical agent such a free chorine. A swimming pool owner must maintain the chlorine level of swimming pool water, the pool pH, pool Alkalinity, chlorine stabilizer (Cyanuric Acid), and pool Calcium Hardness levels so that to keep pool water clean and safe for swimmers.
Irrigation is the application of controlled amounts of water to plants at needed intervals. Irrigation helps to grow agricultural crops, maintain landscapes, and revegetate disturbed soils in dry areas and during periods of less than average rainfall.
The four main methods of irrigation are:
Surface: Water is distributed over and across land by gravity, no mechanical pump involved. Sprinkler: Sprinkler Irrigation is a method of applying irrigation water which is like rainfall. Water is distributed through a system of pipes usually by pumping. It is then sprayed into the air and irrigated entire soil surface through spray heads so that it breaks up into small water drops which fall to the ground. Sprinkler irrigation is suited for most row, field and tree crops and water can be sprayed over or under the crop canopy. However, large sprinklers are not recommended for irrigation of delicate crops such as lettuce because the large water drops produced by the sprinklers may damage the crops.
Drip/trickle: Drip irrigation is one of the most efficient types of irrigation systems. The efficiency of applied and lost water as well as meeting the crop water need ranges from 80 to 90%. Subsurface: Subsurface irrigation, also designated as sub irrigation, involve irrigation to crops by applying water from beneath the soil surface. Subsurface drip irrigation is a low-pressure, high efficiency irrigation system that uses buried drip tubes or drip tape to meet crop water needs.... Water is applied directly to the root zone of the crop and not to the soil surface where most weed seeds germinate after cultivation.
Fire compartmentation is an important element of 'passive fire protection' and is achieved by dividing the premises into ' fire compartments' thought t he use of fire doors, floors and walls of fire -resisting construction, cavity barriers within roof voids and fire stopping to services that penetrate through these compartments.PFP PRODUCTS INCLUDE:
A smoke control system controls the flow of smoke in a building in the event of a fire. It keeps smoke from spreading throughout the building and gives the building's occupants a clear evacuation route, as well as preventing further damage to the building's interior .
Smoke control systems are one of the most complicated and often misunderstood systems within a facility, and rightfully so. It’s important to point out that a true Smoke Control System vs a post fire Smoke Management System are two entirely different animals. To use an analogy from the animal kingdom which illustrates the differences between these two systems let ’ s consider the use of water by a fish (Smoke Control System) and a camel (Smoke Management System). Both the fish and the camel need water to survive, however a fish uses the water as a medium in which to live while the camel uses its water as fuel to travel great distances. Similarly, a Smoke Control System manages the medium of smoke in order to increase egress times so that occupants can escape safely. Conversely, Smoke Management Systems are used during post fire events to remove smoke from a facility and/or restrict smoke from entering specific areas of a facility during general evacuation.
A Smoke Control System can be defined as an engineered electro-mechanical system that uses mechanical fans and dampers in cooperation with electronic monitoring and controls to produce pressure differences across smoke barriers which inhibit or facilitate smoke movement. A smoke-control system is used to achieve one or more of the following design objectives:
A smoke management system is applied to one or more of the following intended uses
Understanding the Smoke Control design and installation process can be difficult with challenges at each phase of the project. These systems are generally code mandated based on occupancy type, architectural construction methods, occupancy loads and a variety of other factors. With no single entity or trade being solely responsible for the entire solution, the interdependency across all professional engineering and installation trades is critical for a successful project.
What are the recommended indoor temperature and humidity levels for homes?
The ASHRAE Standard 55-2017, Thermal Environmental Conditions for Human Occupancy, notes that for thermal comfort purposes, temperature could range from between approximately 19 and 28 °C. A more specific range can be determined from the standard but depends on relative humidity, season, clothing worn, activity levels, and other factors. The standard notes that HVAC systems must be able to maintain a humidity ratio of at or below 0.012. This corresponds to an upper relative humidity level as high as more than 80% at low dry bulb temperatures but may be lower dependent upon factors such as temperature and the other factors listed above. The standard does not specify a lower humidity limit but notes that non-thermal comfort factors such as skin drying, irritation of mucus membranes, dry eyes, and static electricity may place limits on acceptability of very low humidity environments. ASHRAE Standard 62.1-2016 recommends that relative humidity in occupied spaces be controlled to less than 65% to reduce the likelihood of conditions that can lead to microbial growth.
The HVAC mechanical contracting comfort field is dealing with the installation mechanical systems that can provide an artificial indoor climate environment able to meet the comfort need s of the human occupants . Similarly, in industry there is need to maintain an artificial environment to facilitate an industrial process like food preparation or to facilitate working conditions for industrial equipment like a data center. Hence; Heating or Air conditioning systems can raise or lower the temperature /humidity in a controlled manner. The systems are provided with temperature /humidity control system s so the users, depending on the season, clothing worn, activity lever etc , to be able to select their individual comfort conditions that the system would provide. Be able to provide comfort conditions , it is very important because the productivity of the individuals is highly dependent on the comfort levels.
The simplest type of control system is an on/off thermostat or a hydrostat which switch off and on the source of heating / cooling or a humidifier of a dehumidifier acc o rding to the temperature set by the user. Today, the thermostats are fully electronic, smart with connectivity to internet. Depending on how precisely one wants to control the fluctuation on temperature/humidity the control systems can become quite complicate and quite expensive.
In an electric power system, switchgear is composed of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be done and to clear faults downstream
Electricity is used to produce lighting and to power motors and appliances. To power and to switch on /off electricals loads of high voltage either single phase 230V or 3-phase 400V safely, we need switch gears such as the contactors/relays and switches which are housed in distribution boards or panels.
The electrical panel with motorized switchgear usually has a primary high voltage electrical circuit of voltage 230V/400VC and an auxiliary low voltage 24 V control circuit .The low voltage control circuit helps as to extend safely the controls outside the cubicles of the Electrical panels inside the building so as to switch on/off loads and to monitor their operation without needing to provide isolation and without putting in danger the operators in case of electrical leakage.
A control circuit is any circuit that has as its load, the operating coil of a magnetic motor starter, a magnetic contactor, a relay, a pilot light, or any other control device that exercises control of another circuit . In other words, a control circuit exercises control over one or more other circuits .
Building Energy Management Systems (BEMS) are integrated, computerized systems for monitoring and controlling energy-related building services plant and equipment such as heating, ventilation and air conditioning ( HVAC ) systems , lighting , power systems and so on. The phrase Building Energy Management Systems is sometimes used interchangeably with Building Management Systems (BMS), however, strictly speaking, Building Management Systems can be used to monitor and control a wide range of building systems , including fire , smoke detection and alarms , motion detectors, CCTV , security and access control , lifts and so on. Building Energy M anagement Systems relate specifically to energy-related systems . Small buildings may have independent controls for energy systems , but for larger or more complex buildings , sites with a number of buildings , or organizations with buildings on a number of sites , the integration of systems operation through a single Building Energy Management System offers greater control and can achieve significant savings
Increasingly, simple BEMS are being developed that are suitable for even the smallest buildings . BEMS provide real-time remote monitoring and integrated control of a wide range of connected systems , allowing modes of operation , energy use , environmental conditions and so on to be monitored and allowing hours of operation , set points and so on to be adjusted to optimise performance and comfort . BEMS can also trigger alarms , in some cases predicting problems and informing maintenance programmes . They allow records to be kept of historical performance , enable benchmarking of performance against other buildings or sites and may help automate report writing. Claims for the scale of savings that can be achieved by BEMS range from 10% to 25%.
Operated properly, they should allow energy use to be optimised without compromising comfort or performance . However this requires a thorough understanding of how buildings are supposed to perform, and how different systems within them interact. To function correctly they must be properly designed, installed and commissioned and must have a user interface that is easy to operate . They should then be continually assessed and fine-tuned as performance is better understood over a number of seasons and modes of operation , and changes are made to buildings or operations . Maintenance is also necessary to ensure systems continue to operate correctly, for example, replacing sensors and batteries , checking connections, checking the operation of dampers and valves , upgrading software and so on. BEMS can be wired or wireless systems . To determine whether a wired or wireless system is the most appropriate, buildings should be audited to test how well signals can be received and how likely disturbances are.
Choosing the correct BEMS system then depends on the size and usage of the building , the scale of the project and the budget . As a general rule, larger, more extensive projects tend to be best suited to wireless solutions. BEMS may have remote outstations that can be interrogated locally, or may be accessible from mobile devices. However, major buildings may be vulnerable to cyber attack , especially when they are associated with prominent organisations . This can be a particular issue where functions operate in the 'cloud', such as cloud-based analytics , and the ability to access and manage multiple buildings remotely. The ability to access live analytics , or receive alarm notifications from hand-held devices has great potential benefits, but may also bring additional risks .