【 Weak current College 】 heat pump air conditioning system design methods

Abstract: the heat pump air conditioning system design methods: air conditioning load and capacity of the unit type and number of the location of the heat pump, pump selection and arrangement, heat pump air conditioner terminal equipment choices, etc.

Keywords: air conditioning load heat pump air conditioner terminal equipment

1. air conditioning load and capacity of

Air conditioning load including air conditioning air-conditioning cooling load and thermal load. Air conditioning cold (hot) load means indoors air parameters are maintained in the State of design parameters, the unit of time to the building of internal demand, cold (heat). This is an interior design parameters, indoor, device, such as thermal, powder moisture, envelope properties, outdoor air environmental parameters (including temperature, humidity, airflow speed, etc.), solar radiation intensity, and many other factors influencing variables. In the Interior and exterior design calculation parameters of air conditioning cold (hot) air conditioning for the building of the load calculation of cold (hot) load. Let the air conditioning system properly provide cold (hot), to meet the design calculation state building requirements and adapt buildings air conditioning cold (hot) load and its changing needs is a fundamental aim of air-conditioning design.

In the air conditioning system design process, the air conditioning load calculation is the first step, the air conditioning load calculation should include the design and calculation of air conditioning load identification and analysis of various time slots load. Second, the capacity of the device must meet the design and calculation of air conditioning cold (hot) load requirements, device configuration, should be adapted to the characteristics of air conditioning load changes. In order to air-source heat pump type water chiller for cooling of air conditioning system design capacity of the heat pump unit has to take into account the various parts of the building while using coefficient, also taking into account the actual heat pumps, cooling capacity will vary from the actual quantity of heat equipment spacing restrictions cause poor ventilation, some air short circuit (this part of the output loss accounted for about 5 per cent) were affected, and the outdoor heat exchanger for surface area of ash and heat exchanger fouling, equipment attenuation and other factors, the selected heat pump is the safety factor should be considered. Expressed by the formula:

Q=β1·β2·QD。

-, Q-heat pump in the design of refrigeration (heating) in KW

QD-design calculation load, KW

Β 1 — use coefficients, by specific engineering, General 0.75 ~ 1.0

Β 2 – safety factor, generally take 1.05 ~ 1.10.

In addition, the heat pump unit must meet the system requirements for cooling in summer and to satisfy the system requirements of the air conditioning heating in winter. The various suppliers of heat pump rated cooling capacity, rated heating capacity of parameters, and the regional air-conditioning outdoor design parameters are not necessarily consistent. Nanjing, the General vendor heat pump rated working conditions and actual identical or similar, general air dry-bulb temperature is 35 ° c, the air conditioning refrigerant water entering and leaving the water temperature is 12 ° c, respectively 7 ℃. While the winter heating heat pumps for rated operating conditions for the outdoor air temperature 7 ~ 8 ° c, into and out of the water temperature is 50-55 degrees centigrade. This condition and Nanjing area in winter and air conditioning system design is very different from the calculation temperature. Nanjing climate characterized by cold winter and hot summer. For General Office and hotel complex, consisting mainly of winter air conditioning heat load calculation of heating design is about summer air-conditioning cooling load calculation and design of 70-85%. In the heat pump unit selection, you should review the heat pump unit corresponds to the local conditions of meteorological parameters, the calculation of real output. If the heat pump in the design of outdoor parameters of cooling capacity is larger than the design calculation of cooling load and thermal load heating equals, you should choose the heat load for heat pumps. Conversely, if the cooling capacity to meet the design cooling load calculation requirements, the quantity of heat is greater than the required heat, can be considered part of the selection of forced-air cooling type water chiller, part of the selection of the heat pump units to reduce investment. In General, the summer load selected heat pump and can meet the requirements of the winter heating.

2, unit type and number of

Heat pump chiller is different depending on the compressor can be divided into the scroll compressor, heat pump, reciprocating screw-type heat pump and heat pump units, according to the size of the unit structure, combined size of heat pump unit can be divided into integral heat pump unit and modular heat pump unit.

Integral heat pump unit and the modular nature of the heat pump units without distinction, the so-called modular heat pump is a heat pump unit consists of several sets of heat pump units (independent refrigeration circuits, independent of evaporation, condensation, independent of the framework, and even has a separate control panel) in parallel, the unit or any combination of flexibility, a unit of failure does not affect the rest of the unit of work. Each unit's rated cooling capacity to 55KW. Domestic heat pump production enterprise to manufacture modular heat pump units, while the integral heat pump units visually is a combo unit, an overall framework, although internal can have more than one compressor, even more than 2 refrigeration circuit, but they are not subdivided between General. Modular heat pump unit's main advantage is the low noise, small vibration, because the system total refrigeration circuit, in winter the temperature effects on the system when the water temperature. Preparation of system interoperability, in addition, the heat pump unit is generally placed on the roof, modular heat pump unit due to the modular, flexible, all unit size small, weight light, with transport and hoisting, easy installation. If the project is large, modular heat pump units are due to the number of refrigeration units, but the point of failure, and maintain large, rated operating conditions of efficiency also slightly lower than the overall unit. In addition, because of the modular heat pumps generally use the plate heat exchanger, the higher the water quality requirements, the units of the hydraulic balance between the requirements are higher. To sum up, on a smaller system, or on the size, weight lifting, and other special occasions, modular heat pump has its advantages. The modular heat pump should pay attention to three issues: first, the water quality requirements, entry to set higher filtration efficiency of filters, the second is the hydraulic balance is better, the third is assembling blocks should not be too much, so as not to affect heat exchanger air intake area. Usually a group of not more than six units. In the choose when the integral heat pump units, consideration should be given to the air conditioning system load changes in the characteristics and equipment between preparation, taking into account the winterQuarter of the heat pump when defrosting minimize the effect of water temperature. Generally a heat pump air conditioning systems should not be less than the number of 2-3 units, each with air conditioning system configuration of the heat pump unit of total refrigeration circuit number should not be less than 4-6. Of course, the number of the heat pump should also consider building functionality, user Unit Division, measurement, management, and other factors. Amounting to the reciprocating screw-type heat pump and heat pump units, in theory, screw-type heat pump fewer moving parts, less maintenance, high efficiency, low noise. But because of the heat pump for a large part of the noise originates from the fan, and compressor noise can add enclosures, lower, so actually screw heat pump noise ratio piston heat pump noise slightly lower (approximately 3-5dB (A)). In addition, the thermal resistance for heat pump units, mainly in the outdoor heat exchanger, heat pump efficiency is also affected by two for area and other factors, from the engineering point of view, screw-type heat pump and heat pump piston-type differences in efficiency. But screw-type heat pump prices higher than reciprocating heat pump. Question on refrigerants, conditions as far as possible, the selection on the environmental impact of refrigerating machines, such as R407C, R134a, which should be optimized R407C followed by REFRIGERANT R134a, consider that the current prices of the cheapest is R22.

3. the location of the heat pump

Heat pump location is the following one is placed at the top of the podium and the second is placed at the top of the Tower, the third is placed on the windowsill, the fourth is placed higher indoor height. Considering the hoisting and subsequent replacement of the thermal pump was more on the skirt of the roof. When the heat pump on the skirt of the roof, to assess its main building and the surrounding environment, the larger the heat pump unit (≥ 200RT), standalone noise in 75 ~ 85db (A) to the left. Necessary additive noise barriers, or in the main building by a heat pump side to avoid the door, do double window or high quality hollow glass replace ordinary flat glass Windows. Layout of the window sill of the heat pump are often called independent configuration of each layer, separate measures of places is limited to smaller heat pump, use side side exhaust. Selection on the wind pump should be installed diversion duct as side exhaust. Even if the room has a higher clearance, the heat pump on the Interior is not desirable, subject to conditions limit must be set in the room, the room should have voices wind can use, to have sufficient wind area, and air exhaust through the duct organized row to outdoor, prevent airflow short circuit. Plus run-in duct, the fan should be adjusted accordingly to avoid resistance increases reduce ventilation rates. Ideal method or the heat pump on the tower roof so that the heat pump with good ventilation and noise-reduced to minimum. It should be noted that the heat pump can not be near the residence or other noise requirements higher room layout, not close to the residence (rooms) placement above or below the heat pump and water pump. Heat pump units use a spring damper vibration isolation, shock absorber type and layout is determined by the calculation of points. Heat pump depends on the distance of the main building of the parapet and greater than between 3m, heat pump should not be less than 3m, spacing conditions distance should be increased. Heat pump layout in addition to the impact on the surrounding small, good ventilation, you should also consider pipeline layout, equipment installation and subsequent replacement and other factors, have conditions set aside 1 ~ 2 heat pump location, leaving room for development, and for equipment installation and replacement considered sufficient load conditions.

4, the selection and arrangement of the water pump

The number of suitable water pump and heat pump corresponds to the number of computers. Heat pump and water pump of the connection methods to use one-to-one series, heat pump and water pump linkage. Number of heat pump, water pump can stick Pro heat pump, water pump with waterproof performance with sound absorbing hood rain, heat pump, pump a small amount should be centralized in the room. Spare pump can be used to not install a temporary replacement method. If the pump adopts the first water pumps in parallel with the parallel phase of heat pump group, a series of parallel heat pump number not more than 6, and should have a reliable hydraulic balance measures. This connection should be arranged in nearby water pump and heat pump room, can also be placed in the basement, the number of the pump should consider 1 ~ 2 spare pump. When selecting pump specifications, as selected low-speed pump, in order to reduce noise, water pump flow according to the system required flow 1.1 times select, the delivery lift of pump should be equal to the system required to overcome the resistance of the total. Pump power consumption should control the output of the heat pump 1/30. Pump layout to have space, conditions for 1 ~ 2 pumps installation location for development. The pump should also have reliable isolation measures.

5. heat pump air conditioner terminal equipment selection

Summer operating conditions, the heat pump rated for return water temperature 7 ° c respectively, and 12 degrees centigrade, and the general air conditioner rated operating conditions, the selection and calculation of air conditioners and other forms of air conditioning systems. In winter conditions, the heat pump system at the rated temperature (outdoor air 8 ℃), the heat pump rated for return water temperature 47 ° c, respectively in 42 degrees centigrade. But when the outdoor temperature is low, the heat pump system of water supply temperature generally remained at 39 ~ 40 ℃. The water temperature conditions significantly lower than the rated boiler heating system for the return water temperature (60 ° c and 50 ° c), that is lower than average performance parameters given in the table and out of the water temperature rating (also respectively 60 ℃ and 50 ° c), water temperature, air conditioner heat emission there are significant differences. Some scholars so that heat pump air conditioner terminal equipment should be selected in summer condition calculation on the basis of the results has been enlarged. But according to our calculations, Nanjing heat pump air conditioning system can be used at the end of the summer cooling condition of compute results. This is because Nanjing general building heating heat load is less than the summer cooling cooling load, in addition, the same air conditioners, 60 ° c inlet temperature of the heating of water greater than 7 ℃ obvious condition of cooling capacity. In winter when temperature 35℃，inlet water temperature down to 39 ~ 40 ℃, the air conditioner heat quantity to meet the requirements of the indoor heating. In addition, it is customary to the mid-range parameter select air conditioners, in itself, have a certain margin. If the heat pump system with 4 or more refrigeration circuit, defrosting on water temperature will not cause significant fluctuation, it generally does not affect the indoor temperature fluctuations. But when the system heat pumps only 1 ~ 2 circuits, to reduce the cream to indoor temperatures, conditional,You can start and stop control and water temperature of air conditioners, such as when the water temperature below 35 ° c, air conditioner fan to spin down, when the water temperature is higher than 35 ° c fan recovery operation. This will effectively improve indoor comfort.

6. heat pump water system

Large air conditioning system, or a building in the run time inconsistent different features section, or a number of independent measurement of parts you want, or there is resistance from a large number of parts, air-conditioning system should, through the diversity of water are located several subsystems, heat pump and water pump configuration should be adapted to ensure that the system is always in a State of high productivity. System partition should meet some measurement and maintenance requirements, should satisfy the different functional areas are not at the same time operational requirements, to the extent possible, of the same nature air conditioner return to a subsystem and resistance properties comparable to larger air conditioner (fan-coil air conditioners and combined air conditioner or fan-coil air conditioners and air supply unit) Division into different subsystems. All system devices as long as conditions permit, as far as possible using reverse return arrangement. Parallel pump, parallel with heat pumps or parallel pumps-heat pump connections between groups also possible reverse return layout, different water system to connect through a diversity of water, water in set branch pipe yishe thermometers and balancing valves. The parallel loop back to the water pipe conditions also yishe thermometers and balancing valves for observation and water balance. The main equipment (heat pumps, air conditioners, conditioner combination) into the mouth yishe thermometer, software connectors, filters, pressure gauge.

System of a heat pump and water pump connections use loaded connections, i.e. water pumps to water heat pump. Water pump and heat pump are not so far, only the pump suction mount filter. With plate heat exchanger heat pump inlet shall be mounted no less than 60 days/inch filters. Combined air conditioner, conditioner intake should be mounted filters, in-room of the vertical system of fan-coil air conditioners entry should be set water filters, horizontal systems of fan coil units, only in each layer of water intake time dry Park set filter. Water pump entrances should be mounted pressure gauge. The system pressure should be located in water or on the return pipe. System expansion tank bottom should be higher than the highest point above 1 m system. Water tank high out of the living water tank should be used for mechanical water pump. Expansion tank should be set so that the signal pipe where the water level observations. Expansion tank location should avoid for various reasons arise may have spilled water on elevators, etc. Conditions of chilled water system should be changed to effectively address water quantity control hydraulic imbalance and reduce part load case pump consumption. When the system heat pumps and water pumps in parallel with their first-line connections after, to reduce water consumption, the heat pump outlet should device and the heat pump unit linkage of the electric valve.

7. reduce heat pump noise measures

Reduce the heat pump noise impact, on the one hand from the heat pump units, such as a compressor with silencers set, fan-with mute, that is, as far as possible, use low-noise of the heat pump unit. Heat pump units in addition to its own internal compressors pedestal with good shock absorption, heat pump base vibration reduction measures, there should also be possible to choose spring dampers, springs, shock absorbers should be determined by carefully calculated. In addition, in the layout, the heat pump unit should, as far as possible away from the room or a room with adjacent between sound screen, but it should be noted that sound screen should not hinder the flow of ventilation air flow. Generally speaking, the heat pump unit layout to the main building of the impact surface of the roof. From the floor to the heat pump is the importers of roof platform should be soundproof doors and set sound suite, or heat pump unit and building core tube between the auxiliary room (such as water pump, power distribution companies) partition. Water pump is the main source of noise, vibration and noise insulation of water pump. On the roof of the pump with counterweight balancing yishe block spring vibration platform. Conditional will pump placed indoor, rain, noise, water pump room acoustic treatment should be done, such as water pump is installed outside, waterproof covers inside absorption material on noise reduction. In addition, the water pump to choose low-speed pump, water pump room leads to the door in the aisle should do noise gate, conditions set noise gate.

8, air source heat pump air conditioning system and energy-saving measures

The heat pump system, its rated power consumption over the entire building 50 per cent of rated power. Air conditioning system effective energy-saving measures for reducing energy consumption, reduce the operating costs of the building have a noticeable effect and meaning. Heat pump system power consumption is: heat pump units including compressors and cooling fans, Terminal air conditioners, water pumps. Heat pump air conditioning energy saving measures can be divided into the following several aspects.

(1) choosing high efficiency and low energy consumption of heat pumps, reasonably determined number of heat pumps.

In the heat pump air conditioner, heat pump units at the rated operating conditions of the power of the total energy consumption of air conditioning system total 78 ~ 90% (depending on the Terminal air conditioners varies, depending on the form), of which about energy consumption of the compressor system total energy consumption 74 ~ 84 per cent, fan energy consumption accounts for 4 to 6 per cent. So heat pump efficiency and low energy consumption on air conditioning system has a decisive role. The efficiency of the heat pump units are rated operating conditions of efficiency and part load conditions of efficiency. From the information provided by the supplier, the difference in heat pump efficiency, higher rated operating refrigeration coefficient reaches about 3.7, lower around 2.8. High-efficiency heat pumps and energy-saving significance of the obvious. Individual heat pumps can also be based on the outdoor environment parameters change fan speeds, to reduce the power consumption of fan. Buildings air conditioning load with the outside world meteorological parameters and internal usage changes, heat pump unit number and size should take full account of the full load efficiency and part-load of features and efficiency that has been optimized so that the lowest energy consumption throughout the year. In principle, the heat pump unit of not less than 2 ~ 3, independent refrigeration cycle of not less than 4 to 6.

(2) reasonable matching pump

Rated load cases water pump power consumption accounts for air conditioning systems in total energy consumption by 5 ~ 9 percent, and in part load cases, if the matching improperly, pump will not reduce the energy consumption, total system power consumption ratio will be improved.

In addition, the project generally appear in the selected water pumps, water temperature difference is too small. So the pump side energy-saving potential to be tappedDigging. Number of possible water pump and heat pump number match so that part of the heat pump outage, pump the downtime to reduce water consumption. The selected pump should also be as efficient as water pump, water pump flow rate is required, the head should be consistent with the actual. In addition, if you water pump can pump so that the rated operating conditions of the water temperature reaches 5 ° c, while in part load, the water pump flow rate is also changed, of course, should not be less than the heat pump unit minimum qualified traffic, its energy-saving effect is more pronounced. With inverter technology renovation of the existing project.

(3) the use of automatic control methods

Part load, heat pump unit into the number of reasonably determined, the need for heat pump units for group control, to make the pumps running number and heat pump synchronization, you need to take control of variable water system. Let the water pump in qualified scope variable water also need reliable heat pump and water pump control. The new wind of organization and control (according to the outdoor environment parameters or carbon dioxide concentration control fresh air), air consumption can be reduced to a minimum, sometimes also available in outdoor fresh air to cool down naturally, maximum limits to reduce energy consumption.

(4) at the end of the energy-saving air conditioner

Terminal air conditioners consumes energy in occupies the entire air-conditioning system energy consumption by 5 ~ 17 per cent, when the Terminal air conditioners to fan coil unit as primary, the share of energy consumption, mainly in combined air conditioner, its energy consumption is the ratio of the total energy consumption increases. Therefore, the angle from reducing energy consumption, small and dispersed more energy for air conditioning. In addition, the high and low air enthalpy difference of air conditioner power consumption less than low enthalpy difference large air volume and air conditioners. On air without strict requirements of comfort air conditioning facilities, especially in shopping malls, and other personnel gathered more places, large enthalpy difference air conditioners can reduce energy consumption and reduces wind Road area, save duct system inputs and building space. General Cabinet, combined air conditioner often has four pipes, six pipes and tubes. From the save point of view, as little use four pipe air conditioner, air conditioner with six pipes, on combined air conditioner can consider eight rows tube air conditioner. In addition, because the proportion of energy consumption accounts for a lot of air conditioners, part load cases, minimize the energy use of air conditioners have obvious value. Regardless of whether the water system, air conditioner set vwv third gear variable speed is needed. In water systems, conditional on adopting inverter air conditioners etc speed method thermostat can minimize the energy use of Terminal air conditioners. Introduction to air conditioner power as the standard measure of air conditioning systems, air-side variable speed control allows measurement more objective. Terminal air conditioners of energy can also be reflected in the when the outdoor air enthalpy value lower than the room air enthalpy, as far as using outdoor air cooling and indoor air. Double fan group type air conditioner system or discrete but simultaneous control of fresh air and exhaust air system can achieve this effect.

(5) improvement of the environment, prevent airflow ventilation circuit

Heat pump environment of ventilation is the heat pump can operate efficiently, or even whether the normal operation of the very important criteria. Well-ventilated standard is, into the air as heat pump air heat pump, air emissions and timely discharge, platoon, the heat pump unit exhaust and inlet not short-circuit. To achieve this goal should strive to heat pumps and parapet of sufficient distance, or parapet on sufficient area for inlet and, secondly, the heat pump from core barrel and sufficient distance from the main building, the heat pump and heat pump also should get some space distance, the distance should normally be more than 3 meters. Convenient for beautiful and layout, heat pump units are aligned side-by-side layout, improved ventilation, heat pumps can be staggered. In addition, attention should be paid to the effects of wind direction, as far as possible avoid heat pump layout to the main wind direction by building 45 ° dark area. In the heat pump units side by side arrangement, in heat pump between cold gate to more effectively reduce short circuit, and the other to improve breathing environment, on the winter rain or snow extent weaken product cream good results, this measure can reduce summer heat pump suction gas temperature, reducing the sun radiation on the surface temperature of the heat exchanger. Cool, you can set the pump under the fence, but also for the day-to-day maintenance and create a better environment.

Heat pump units should not be placed in the room, not layout to align each floor balcony. If the layout to the balcony to balcony to highlight the overall plane, yishe in well-ventilated corner, use side exhaust, or on the vertical wind heat pump and anemometer tube level exhaust fan, but shall be adjusted accordingly. Had placed indoor heat pump must be run-in wind pipe, exhaust extraction outdoor, and avoid the outlet and inlet too close together to form short circuit. Similarly as with anemometer tube, heat pumps are equipped with fan should be adjusted to suit new ventilation conditions.

Air heat pump around is very complex, you can calculate the flow dynamics simulation of airflow, to seek the best arrangement of ventilation.

(6) of the exhaust and energy saving

Air conditioning buildings account for a considerable proportion of the load, rated load cases, Office, hotel and other buildings of fresh air conditioning load accounted for 30 per cent of the total load, commercial building in the fresh air load accounted for 50 per cent. Fresh air in the amount equal to the exhaust and air permeability and intrusive wind and air flow. Will permeate the wind, into the wind to a minimum, will exhaust organized through the recovery of total heat exchanger in which energy-saving with obvious meanings. As a result of poor air quality in China, the dust content of the air, to the total heat exchanger management trouble, but also shortens the total heat exchanger service life, thus affecting the total heat exchanger of a large number of promotion. For heat pump system, such as exhaust air can be organized to row to heat pump portal, is conducive to improving the efficiency of the heat pump unit, is a simple and efficient energy-saving measures.

(7) other measures

In the hot summer, many works of heat pump units due to ventilation or unit quality problems, the water temperature is very difficult to be guaranteed in this case at the inlet side to the heat exchanger water spray method can receive significant effect. The negative consequences of the water can cause heat exchanger surface scale and impact of heat, but also because the coil of dust on the surface, scale may not be directly in the coil surface even impact of heat transfer. In order to prevent the fouling, spray softened water is the root of the problemThis method, but increases the cost. To improve water efficiency, water should be changed to the amount of spray, spray just right, how much spray the most efficient, non-soft water spray effects and the adverse impact how much is worth deep step research.

(8), runs and energy saving

From the preceding discussion of heat pump performance curve of the thermal pump water temperature changes can change the efficiency of the heat pump unit. For example, in the ambient temperature is 30 ° c water temperature is 12 ° c, heat pump efficiency than water temperature 7 ° c higher than 6 per cent, the ambient temperature of 30 ° c, the water temperature is 15 ° c heat pump efficiency as water temperature is 7 ° c in 1.07 times. Water temperature changes will reduce terminal air conditioners with heat transfer efficiency, but in part load conditions, the right to reduce the water temperature is also able to meet the requirements for Interior. Winter conditions have similar results, the outdoor temperature to-6 ° c (Nanjing outdoor design temperature for air-conditioning design), heat pump water temperature to 40 ℃ pm of efficiency, the water temperature is 50 ° c for 13 per cent efficient at 0 ° c, heat pump water temperature 40 ° c to 50 ° c water efficiency is at 1.14 times. Nanjing and have similar climatic conditions of the region, the water temperature 40 ° c in winter to satisfy end air-conditioning heating requirements.

In addition, the air conditioning system at work who arrived before the opening, saving, because the envelope and the regenerative properties, such as furniture, air-conditioning heat pump than hours ahead of time off for half an hour to 1 hour, does not affect the overall comfort and significant energy saving effects. Early on, shut down the exact time in advance in accordance with the building envelope, indoor furniture features, functionality, and so on, varies by project about half an hour in advance generally open, stop heat pump programme is an effective and practicable.

The temperature of the heat pump unit shall be for actions, instead of heating during defrosting, refrigeration, heating efficiency significantly. Improvement of defrosting control, improve the intelligent defrosting control accuracy is heat pump units to improve performance of one of the important issues. In the use of non-intelligent cream controller of heat pump operation management, management personnel according to climatic characteristics, at any time under the climate change adjustment of defrosting gap and defrosting time can significantly increase the heat pump for heating efficiency, reduce energy waste.

In addition, the heat pump and thermal storage air-conditioning technologies that can be played on the electric peak load shifting role, has an obvious social benefits and a good market prospects. Heat pump condensing heat recovery should also be manufacturers, owners, project designers energy issues of mutual concern.

In short, the heat pump system using extensive volume of space, energy, energy savings. Promotion of energy saving technology improvement of heat pump system, optimize the design of the new heat pump system, significant energy savings, with significant economic benefits, energy efficiency, environmental and social benefits.