25 most commonly problems with heat pumps!

TWENTY FIVE PROBLEMS WITH HEAT PUMPS According to European Union regulations circulation pumps are not considered when determining efficiency of the heat pumps. Insignificant mistakes upon installation of a heat pump may reduce its efficiency up to 50%. It is expensive equipment – in comparison with other types of heating systems! If automation of “weather conditions” is not applied, a heat accumulating container (heat accumulator) is installed. Such a connection pattern reduces operating COP by 30% - 40%. (decreased COP!) According to the design of a heat pump, it “does not like” high temperatures in a heating system – efficiency of a heat pump is decreased. (decreased COP!) Repayment period of heat pump costs is at least 10 years. During this period you are not able to update the system and have to make high capital investments. While using the heat pump circuit, it is freezing, thus, its efficiency is also reduced as accumulated (collected) heat temperature decreases. (decreased COP!) Efficiency specified in the technical data is obtained in “perfect” circumstances of a laboratory. Operating efficiency usually is lower by 8 - 10% of the stated value in the technical documents. (decreased COP!) The automation of “weather conditions” is required, as without it heat pump’s efficiency is low. There are certain working conditions and situations when heat pumps are not able to heat the whole area! Anyway it will be necessary to set up additional heating devices! Even when obtaining a heat pump free of charge (a heat pump price makes only the third part of the entire value of the heat pump unit), you will have to pay a lot of money to connect it (do you want to be an investor for construction companies and heat pump manufacturers?). When ice freezes on the heat pump radiator (it becomes covered with ice), a heat exchange surface with air noticeably decreases – almost by 21 times. The heat exchange intensity decreases approximately by the same value. (decreased COP!) It is necessary to spend time and power to defrost the radiator which also decreases the total efficiency. (decreased COP!) At increased air humidity the radiator becomes covered with ice very intensively (it is especially relevant for coastal regions). Together with capital investments to install a heat pump it would be correctly to add also expenses related to transition to a heating system of reduced temperature (installation of heated floors, additional radiators or replacement of the existing ones with bigger and more powerful ones). Most often this problem is withheld! To prevent continuous icing of the earth heat exchanger’s circuit (circle), one of the parallel collectors has to be disconnected. Thus, the amount of the necessary earth circuit together with the price increases at least twice. Expenses for an increased heating system are included in the cost estimate already in the stage of design. It means that reduction of the price is not possible (if promised, it is delusion)! Defrosting cycle of the heat pump may switch on very often significantly reducing the efficiency of the heat pump and becoming a potential reason for decreased temperatures within premises. (decreased COP!) The actual COP is 1.7 when the temperature in the radiators is +50°C! Most of the heat pump manufacturers state it more than 2.0 (the source – Department of Natural Resources of Canada). (decreased COP!) A heat pump has to be protected from wind and it has to be ensured that there is no recirculation of air already used. Drainage has to be connected to the inner sewerage. The heat pump has to be located outside, so it is impossible to ensure perfect isolation of the heating main without heat loss. Ventilators and compressors make sound and vibration. A special supporting plate is required. It is not a complete list of problems yet... Continuous run of the inner unit’s ventilator (if working mode is set manually) may reduce efficiency of the heat pump. (decreased COP!) A condition of filters and heat exchangers is extremely important for productivity and work resource of the heat pump. (decreased COP!) Filters have to be checked once a month, decrease of productivity and load may result in failure of the compressor. Velocity of the ventilator and tension of straps also have to be checked on a regular basis. If it is below +10°C and falling for at least two more degrees – efficiency decreases by one unit. It means that the COP will be 1 at +6°C! What’s the use to make such capital investments? This is the most important issue! Let us say – the outside temperature is +3°C (or even colder) and relative humidity is 95%. It means that it is cold, cloudy and wet outside. In such a case the maximal heat is necessary, however, the heat pump or conditioner may produce only little amount of heat in comparison with its rated capacity as it is being covered with ice! Thus, when heat is needed the most, other heat sources have to be used. However when the necessity is the least – the expensive heat pump gets down to work. Ask to heat pump vendors: What will be capacity produced by this device in premises if it is -3°C outside, there is wet snow and, thus, air humidity is 100%? How much electric power will be consumed in such weather conditions? Most likely you will not receive the answer. After the aforesaid it would be reasonably to make calculations – to divide the price of a heat pump and its installation with the number of cold days during its warranty period. Isn’t it more profitable to heat premises with an economical, convenient and quiet ion boiler?