Scanair is also the pioneer of new generation of low-temperature Heat Pumps for drying products – cold air dryer for the food, chemical, pharmaceutical, aquatic products, vegetables, etc. The preferred drying processing equipment, the cold air dryer dried foods not only to maintain the original quality and easier to package storage and transportation cold air dryer for drying all kinds of high quality, uniform and other food and vegetables and herbs. Control technology and its performance can be comparable with similar foreign products environmental control desiccant temperature 10-35 degrees Celsius. Dehydrating effect, the material no distortion, no color, full. Especially for fish and shrimp, fish, river fish, dried shrimp, abalone, sea cucumber, shark, squid, fish, aquaculture, river fish, ginseng, mushrooms, mushrooms, herbs, vegetables, fruits, meat, poultry, pet food, honeysuckle and other seafood drying dehydration. Heat pump dryers are suitable for all products dried in the range of 40-80 °C, and especially have been widely applied in industries such as pasture grasses, seafood, meat and clothing.
Heat Pump systems are available in various of types and combinations that you can apply almost any application. For heating purposes, they can be divided into basic types, determined by the source and the destination of the heat and the medium that the heat pump uses to either absorb or reject the heat in each of these locations. Also the heat ex-changers the heat transfer media can be either liquid (water, or glycol mixture) or Air, sometimes it is a combination of the two. In describing the type of heat pump, generally the heat source is provided first, followed by the destination or heat sink.
The variations in common use are
- Air to Air
- Water to Water
- Water to Air
There are few heating and cooling applications that cannot benefit from heat pump technology and in doing so deliver significant energy efficiencies. Heat pumps are available to claim free or waste heat from a number of places.
- Ambient air
- Ground water
- The ground itself
Commercial applications where unwanted heat would be rejected, Heat pump technology can be used in applications as diverse as space heating or cooling for human comfort in offices, homes and all kinds of residential installations. They can also be found in commercial applications where large quantities of air is available for drying, swimming pools heating and factory dry process production. Most heat pumps are driven by electrical power, natural gas or Liquefied Petroleum Gas (LPG) can power certain systems that drive an internal combustion engine in place of a conventional electric motor.
Many homes can now benefit from a variety of installations, including ground source, most suitable for certain new-build properties and small split or multi systems applied to existing premises. Air to Air systems use a small room unit to heat or cool the living space by re-circulating room air. Alternatively a number of rooms can be conditioned with a multi-system. Water to Water or Ground to Water systems provide hot water that can be circulated through Fan Coil units, radiators or, preferably, under floor heating pipes to provide space heating. Domestic hot water is also supplied at temperatures up to 55ºC – some Heat Pumps can provide 65ºC.
Air to Air and Air to Water heat pumps are frequently used in office and retails spaces, they are often installed in roof top of the building or sun shades and offer substantially favorable cost comparisons against conventional boiler systems when measured against installation and running costs. Heat pumps are used in many industries, to recover heat or as an integral part of the process. Swimming pools can use heat pumps as the primary source of heat for the water in the pool, showers or to augment an existing fossil fuel system. In enclosed swimming pools, de-humidification is necessary and the heat recovered from the vapour in the air by a dehumidifier is easily returned to heat incoming fresh air or through a heat ex-changer.
HEAT PUMPS FACTS
Heat pump is a device for transferring energy in the form of useful heat from one place to another. It cannot store, make or destroy heat energy – it simply moves it. There are a number of techniques that exploit heat transfer; the commonest in use is the Refrigeration Cycle. Heat pump is capable of transforming a large quantity of low grade, low temperature heat. Some air source systems will operate in winter ambient conditions down to -15ºC. Heat pumps are available that can operate in a variety of media Air, Water, glycol, etc. It is an efficient and space saving means of heating a wide range of premises. It can also provide cooling to these premises.
The vast majority of Heat Pumps work on the same principle as the domestic refrigerator utilizing a vapour compression cycle but for heating the Heat Pump utilizes the ‘hot end’ of the process. The vapour compression process utilizes low grade heat that is normally too cool for human or process requirements and lifts the same quantity of energy to a higher temperature that is suitable for human comfort.
The thermodynamic cycle occurs at constant energy content throughout even though the temperature has been increased from say 5ºC to say 35ºC. A refrigerant is utilized in the cycle to act as the transfer medium and the only prime energy required is the energy to circulate the refrigerant.
Depending on the application and type of Heat Pump utilized efficiencies of 300% to 500% are normal. When dealing with Heat Pumps efficiency is known as Coefficient of Performance (COP), so the COPs for the above example would be 3 to 1 and 5 to 1.
In its simplest form this relates to HEATING OUTPUT divided by the POWER INPUT E.g. with a COP of say 4 to 1 the HEATING OUTPUT relates to 4 Kw and the POWER INPUT 1 KW.
Note: Remember that COPs are instantaneous measurements of performance and are usually quoted by manufacturers to an international standard. COPs will vary according to the air or water entering the heat pump and with the temperature of the air or water being treated by the heat pump.
Heat Pumps emit considerably less CO2 to the atmosphere than gas or oil fired heating systems so they are environment friendly and the low grade heat source utilized is considered to be a renewable energy source (CO2 reduction is generally proportional to the COP for each application).
Yes of course. Due to the dynamic nature of Heat Pumps their capital cost is higher than conventional heating systems, however, the savings delivered in energy efficiency allows for very low operating costs. When utilized in commercial buildings that also require cooling additional cost benefits occur as there is no need to expend further capital on a second system.
New customers are often confused by the comparison and selection between heat pumps and solar water heaters. They are often asked such questions by their technical’s. Why should I choose heat pumps rather than solar? What’s the advantages of heat pumps compared to solar?
On below 4 aspects, heat pump water heaters are better than solar water heaters
- Less Investments. Those water heating projects for hotels, factories, schools, swimming pools usually needs huge quantity of hot water. For the same capacity of hot water supply, the investment of heat pumps is less than solar water heaters.
- Limitless Usage. Solar water heaters are affected by the weather. If it’s cloudy, snow, or in nights solar water heaters can’t work normally. While, heat pumps are able to work all the 24 hours and not affected by weathers.
- Less running costs. Heat pumps rarely need assistant electric heating. While solar water heaters often need electric heating because of their restricts.
- More convenient installations. The spaces for installations of heat pumps are much smaller than solar. And the locations for installations of heat pumps are much more flexible. In fact many commercial projects don’t have enough spaces or ideal locations for solar water heaters. While there’s no such questions if they are heat pump systems.
Heat Pumps are normally classified by their heat source and means of delivering the heat:
Air to Air : Heat pump where the collecting medium is air and the destination medium is also air. Generally, most commercial small split and packaged systems are direct air to air it has been used in air conditioning application.
Water to Water: A heat pump where the collecting medium (source) is either ground water or a glycol from solar collectors solution and the destination medium is also water or glycol. These systems are invariably indirect.
Air to Water: Air to water systems are most common used in India single packaged units. An outdoor unit collects heat from ambient air and delivers it to the conditioned space by means of water or glycol circulated through fan coils. This type of system uses a mixture of direct acting outdoor unit coupled with an indirect indoor section. Used in many applications such as in conjunction with fan coil units in commercial buildings, for heating swimming pools, and for providing domestic hot water, hotels, mane more and Space heating for offices.
Water to Air: Water source systems are used where a supply of ground water, ponds or lakes are available. These systems are invariably indirect and need careful filtration to remove particles from the water source before it enters the heat ex-changer. Can use wells or boreholes, but can also be configured as many units connected together on a common closed water loop to enable energy transfer from hot to cold points in a building.
Ground to Water: As above but utilized with under floor heating systems, medium temperature heat ex-changers or fan coil units. In addition to this products Scanair manufacturers many configurations like single package, split package, ductable, rooftop mounted, part of a centralized system, zone system, or stand alone models.
Heating only heat pump: Ground Source heat pump systems are often optimized specially to deliver heating only these units are often capable of delivering greater overall energy efficiencies than reversible units because the system is designed for a constant unvarying load above the freezing point of water at the evaporator section and can dispense with the defrost Cycle.
Compressor: The compressor is often referred to as the heart of the refrigeration or heat pump system. It serves two main purposes. The first is to circulate the refrigerant fluid through the circuit like a pump, the other is to compress and raise the pressure and temperature of the refrigerant vapour so that it can easily be condensed back into a liquid to resume the heat transfer process.
Reverse Cycle Heat Pump: A reverse cycle system is a refrigeration system that can, by means of a valve that reverses the flow of the refrigerant fluid, change the operation of the system from heating to cooling. Or to facilitate defrost.
Heat Ex-changer: A heat ex-changer is a device for the transfer of heat energy from one medium to another. It can take a variety of different forms the common in everyday use is a central heating heat ex-changers where hot water is circulated through pipes or plates and gives its heat up to the surrounding air.
Evaporator: In refrigeration systems the evaporator is the heat ex-changer where refrigerant fluid is evaporated it absorbs heat from the surrounding air or water, thereby reducing its temperature.
Defrost Cycle: Where reversible air source systems operate at low ambient temperatures, the evaporator in the outdoor unit may attract moisture from the air at low ambient temperatures that will freeze forming a coat of ice. This is a function of the natural humidity outdoors and is not abnormal. This coating of ice is removed periodically with an automatic defrost cycle. The frequency of the defrost cycle is controlled automatically by a combination of time and temperature of the external coil.
Condenser: In refrigeration systems the condenser is the heat ex-changer where Hot, compressed refrigerant gas is condensed to a liquid and further cooled to evaporator around the circuit.
Capillary Tubes: Any fluid flowing through an orifice will experience a drop in pressure. A capillary tube is a precisely measured length of a narrow tube with a predetermined internal diameter that produces the desired drop in pressure along its length.
Thermostatic Expansion Valve (TEV): An automatic mechanical valve that is self compensated for the pressure losses in the evaporator and controls the leaving super heat temperature of the refrigerant.
Electronic Expansion Valve (EEV): A valve that is driven by a small dc stepping motor operates in the same way as a TEV although the valve positioning is determined by a microprocessor EEVs are capable of more precise metering and are found mainly in fully automatic systems.
Refrigerant: The heat transfer fluid contained in a heat pump refrigeration circuit. Normally this is a chemical contained in a hermetically sealed circuit that has a low temperature boiling point refrigerants can be one of a number of man-made Fluorocarbons or a Hydrocarbon compound.
Ground Source Heat Pump: Heat pump installation that uses the earth as a heat sink to store heat or as a source of heat in the India temperature below ground at a 4 feets to 20 feet depth is stable within a small tolerance year round. Heat can be stored or obtained from shallow ground, about 50feet depth, or by deeper bore-holes where space is a consideration.
Inverter Drive or Variable Speed Drive (VSD): Refrigeration systems in air to air heat pumps are often subject to wide variations in capacity and demand. A VSD system uses electronic speed control to vary the speed of the compressor motor. The motor speed can be increased to compensate for low ambient temperature conditions when less heat is available to use or decreased during mild weather. VSD systems are capable of high energy efficiencies because they match the unit’s capabilities to demand also known as VRV (Variable Refrigerant Volume) and VRF (Variable Refrigerant Flow).
CoP: (Coefficient of Performance): Used as a ratio, CoP is an expression of the output of a machine in heating mode. The rated capacity divided by the rated total power input. In practice this is expressed as a single figure or sometimes as a percentage. For example, a system that is rated in heating at 6.5kW, with a rated power consumption of 1.8kW will have a CoP of 3.61 or 361%.
CoP = Heating Output (kW) / Total Energy consumed by the system, including fans, pumps and controls (kW)
Energy Efficiency Ratio (EER). The out put of a machine in cooling mode. The rated capacity is divided by the rated total power input. In practice this is expressed as a single figure or sometimes as a percentage.
EER = Cooling Output (kW) / Total Energy consumed by the system, including fans, pumps and controls (kW)
Kilowatt: The SI unit of power. It is used to specify the thermal performance of a Heat Pump as well as the power energy it consumes.
Kilowatt Hour (kWh): The standard unit of sale of electricity, it is the equivalent power consumed by a purely resistive load of 1000 Watts (1kW) for 1in hour. Your electricity supplier will specify the price in your supply contract.