Heat Pump Knowledge
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Heat Pump Knowledge

Heat Pump Knowledge

What is a heat pump and why we choose it to heat and cool?

What is a heat pump?A heat pump is an electrical device that extracts heat from one place and transfers it to another. The heat pump is not a new technology; it has been used around the world for decades. Refrigerators and air conditioners are both common examples of this technology.Heat pumps transfer heat by circulating a substance called a refrigerant through a cycle of evaporation and condensation (see Figure 1). A compressor pumps the refrigerant between two heat exchanger coils. In one coil, the refrigerant is evaporated at low pressure and absorbs heat from its surroundings.The refrigerant is then compressed and sent to the other coil, where it condenses at high pressure. At this point, it releases the heat it absorbed earlier in the cycle. Refrigerators and air conditioners are both examples of heat pumps operating only in the cooling mode. A refrigerator is essentially an insulated box with a heat pump system connected to it. The evaporator coil is located inside the box, usually in the freezer compartment. Heat is absorbed from this location and transferred outside, usually behind or underneath the unit where the condenser coil is located.Similarly, an air conditioner transfers heat from inside a house to the outdoors.The heat pump cycle is fully reversible, and heat pumps can provide year-round climate control for your home heating in winter and cooling and dehumidifying in summer. Since the ground and air outside always contain some heat, a heat pump can supply heat to a house even on cold winter days. In fact, air at –18°C contains about 85 percent of the heat it contained at 21°C.A heat pump water heater can heat or cool , the heating function is used the most, and commonly used for house heating, domestic hot water or swimming pool water heating. It absorbs heat from air or ground, then transfers the heat to water for pool water heating, room heating by radiator, underfloor coil or water fan coil. According to the souce of the heat , there are two types of heat pump water heater, one is air source heat pump and the other is ground source (also called earth energy, geothermal) heat pump. An air source heat pump absorbs heat from the outdoor air in winter and rejects heat into outdoor air in summer. It is the most common type of heat pump found in homes at this time. A ground source heat pump which draws heat from the ground (soil, rock) or water (underground water, river, lake), are also becoming more widely used. Why we choose it to heat and cool?Heat pump is a low-carbon energy-saving product, it is high efficiency, energy-saving, safe and reliable, environmentally friendly, intelligent and durable. It can be used all year round the year. The use of heat pump will not be influenced by bad weather such as overcast, rain, snow, and it does not produce any exhaust gas, waste water and waste residue emissions. The operation cost of heat pump water heater is only 1/4 of the electric water heater, 1/3 of the oil and gas water heater, and 1/2 of the solar water heater, therefore installing a heat pump is an effective way to reduce our energy costs.

How many types of air source heat pump do we have?

Usually, we say air source heat pump for the heat pumps whose heat source is air, which means they absorb heat from the air and transfer the heat to water. However, there are different types of air source heat pumps if we classify them based on the application and the different technology used on the heat pumps.Based on the application, air source heat pumps includes air source heat pump for swimming pool water heating (usually we call it swimming pool heat pump) and air source heat pump for house heating or domestic hot water. Based on the different compressor technology, there are on-off (constant frequency) air source heat pump, DC inverter air source heat pump and EVI air source heat pump which works at minus 25 degree.

How does the EVI heat pump compressor work?

Copeland EVI Scroll compressors are equipped with a vapor injection connection for Economizer Operation. Economizing can be accomplished by utilizing a subcooling circuit similar to the circuit shown in Figure 1. This increases the refrigeration capacity and the system efficiency. The benefits provided will increase as the compression ratio increases.The schematic shows a system configuration for the economizer cycle. A heat exchanger is used to provide additional subcooling to the refrigerant before it enters the evaporator. This subcooling process provides the increased capacity gain measured in the system. During the subcooling process, a certain amount of refrigerant is evaporated. This evaporated refrigerant is injected into the compressor and provides additional cooling at higher compression ratios. The P-h diagram (Figure 2) shows the theoretical gain in system performance acquired by using the economizer cycle. The extension outside of the vapour dome provides the enthalpy increase, enhancing system performance. Although power increases due to the vapour injection into the compressor, there is still a significant efficiency gain because the capacity gain exceeds the power increase. (The above content is from EVI Theory of Operation by EMERSONSON Climate Technologies)With the EVI heat pump compressor technology, the EVI heat pump is able to work down to  -25℃ the minimum. It works efficiently in heating to provide stable and comfortable heating or hot water for our house.

How to work out the swimming pool heat pump's heating capacity needed for our pool?

It is complicated to work out the heating capacity needed for the swimming pool, if we base on the strict calculation way with all factors considered inside. It's not an easy things for people who are not in the field of heat pumps. Here we'll introduce a simple way to help you to work out the heat capacity needed for our swimming pool. Before the calculation , we need to know the pool size, the initial pool water temperature (usually equal to the ambient temperaure) and the target water temperature. The following is the calculation formula.Heating demand of the swimming pool = C * 1.163 * △t  / TWhere:C = cubage of the swimming pool water  ( in m3 )△t = target water temperature  -  initial water temperature( for instance, if you want to heat the pool water from 20℃ to 30℃, the △t  = 30℃ -20℃ = 10℃ )T = heating duration ( we can choose 24 hours, 48 hours or 72 hours,  the shorter the time, the quicker the pool water becomes hot, as the heating power of the swimming pool heat pump will bacame larger accordingly)If we want to heat up the pool water in short time, we can put the heating duration short, then the heat capacity of the swimming pool heat pump will be larger. The heating duration is the first time to heat up the swimming pool, as usually there is thermal insulation for the swimming pool, the following heating duration will be less than the first time if the thermal insulation is well made.With the above instruction , it will help us to work out the swimming pool heat pump suitable for our pool size.

What are the advantages of the DC inverter heat pump?

DC inverter heat pump becomes a trend and popular in recent years. It is well known because of its changeable running frequeny, then what advantages do the dc inverter heat pump has? The DC inverter heat pump is with soft start, so the starting current is low. It can work down to  -25℃,  provides us with comfortable and constant water temperature. It is high efficiency, energy saving, environment friendly, as well low noise. 1) Soft start, low starting current With soft start function , the heat pump can start smoothly and so reduce the starting current to avoid the trip due to the overcurrent. Besides, because there is no current impacting on the compressor, the lifespan of the DC inverter heat pump machine is prolonged. 2) Comfortable and constant water temperature The running frequency of the inverter heat pump compressor is automatically adjusted based on the change of the ambient temperature and water temperature. When the ambient temperature is low, the compressor runs in high frequency and the target water temperature is reached quickly. When the ambient temperature is high, the compressor decreases the running frequency and runs in low frequency to keep the water temperature stable. Thus the room temperature or hot water temperature is always comfortable and constant.3) High efficiency and able to work down to -25℃As the variable running frequency at the different ambient temperature, it makes the DC inverter heat pump more adaptable to work in low temperature environment and work down to -25℃, meanwhile make sure the efficient heating at low temperature.4) Low noise There is no frequent start and stop on the heat pump machine so it is not only less noise but also energy saving. Besides, when the DC inverter heat pump runs in low frequency , the noise is also relatively low, so it provide us more quiet and comfortable environment. 5) Energy saving and environment friendlyAs any of other types of the heat pumps , DC inverter heat pump is a low-carbon energy saving product. It does not produce any exhaust gas, waste water and waste residue emissions. The operation cost of the DC inverter heat pump is only 1/4 of the electric water heater, 1/3 of the oil and gas water heater, and 1/2 of the solar water heater, therefore installing a DC inverter heat pump is an effective way to reduce our energy costs.

What are the advantages of the EVI heat pump?

Low temperature air source EVI heat pump is widely used in the cold region of Europe. It adopts EVI compressor, of which the heating efficiency is 50%~80% higher than the conventional air source heat pump at low temperature. When the ambient temperature drops significantly, the attenuation of the heat power is very small, this guarantees the heating effect of the heat pump. The EVI heat pump is commonly used for room heating  and domestic hot water in EU market due to the advantages as below.1) Working temperature down to -25℃With EVI technology, the EVI heat pump can work at -25℃ the minimum , so it is suitable for the cold region with low temperature in winter. It can normally work at -15℃ and the heating energy efficiency ratio is 2.0.2) Water outlet temperature up to 65℃The water outlet temperature of the EVI heat pump is up to 65℃, very suitable for traditional radiator heating which required high water temperature.3) Energy saving and environment friendlyAs any of other types of heat pumps, EVI heat pump is a low-carbon energy saving product. It does not produce any exhaust gas, waste water and waste residue emissions. The operation cost of the EVI heat pump is only 1/4 of the electric water heater, 1/3 of the oil and gas water heater, and 1/2 of the solar water heater, therefore installing EVI heat pump is an effective way to reduce our electric bill.

How to set water temperature for the air source heat pump ESD series?

The water temperature of the heat pumps is usually set in the commissioning in factory. But some end users want to set the target water temperature as they desire and need, so here we put the instruction on the water temperature setting for theire easy use. This instruction applies to the swimming pool heat pump ESDPH series and house heating& domestic hot water air souce heat pump ESDAW series.The parameter setting should be done in the standby mode. In the ON mode of the unit, we can check the current values of the parameters, but we can’t modify them. So please set the parameter value in the standby mode.Standby mode means that the unit is plugged to the power, but is not turned on to run.1) In the standby mode, press SET button to enter into the parameter setting page. After pressing the SET button, we also have entered into the first parameter setting page. It will display parameter 00 (water inlet temp in cooling mode).2) Press SET button again, then we enter into the second parameter setting page. It will display parameter 01 (water inlet temp in heating mode). Then adjust the temperature by up or down keys, till to the temperature value we want. (Press the SET key to switch the parameter page from one to the next.)3)  Please pay attention that, when we are in the setting page of parameter 02, we need to press the “up” and “down” key at the same time till we hear a tick, then we can switch into the following setting pages by pressing key SET and set the value by “up” and “down” keys.Please refer to the following views:   If we want to adjust the value of other parameters, it is the same way to enter into the setting page of this parameters. This instruction applies to both the swimming pool heat pump ESDPH series and house heating& domestic hot water air souce heat pump ESDAW series.

What's the HS Code of heat pump?

The full name of HS Code is International Convention for Harmonized Commodity Description and Coding System. Simply, it is Harmonized System and we usually call it HS Code for short.Heat pump HS Code is usually required for importing or exporting in the internaltional business. The import & export process can not go smoothly  if we  don't provide HS Code or we give the wrong code. What's the function of the HS Code and what HS Code do we usually use for our heat pumps ? The HS code is mainly used for the commodity supervision, commodity Inspection and relevant taxes collection  by the customs office.The heat pump HS code we usually use is 8418612090, and for heat pump spare parts, it is 8418991000. Those codes apply to both air source heat pump and ground source heat pump.Heat pump HS Code: 8418612090Heat pump spare parts HS Code :8418991000There are also other HS code for heat pump based on the other features or standards of the heat pump, but the above codes are used the most for our heat pumps, able to help us go through the customs clearance smoothly.