temperature operation of air conditioners
Second law of thermodynamics states: ” The heat spontaneously moves from hotter bodies to bodies less heated .” Is it possible to force the heat to move in the opposite direction ? Yes, but in this case, additional costs of energy ( work) .
Systems which heat is transferred in the reverse direction is often called heat pumps. The heat pump can be a vapor compression refrigeration system , which consists of the following major components : compressor, condenser , expansion valve and evaporator. Gaseous refrigerant enters the compressor inlet . The compressor compresses the gas , with its pressure and temperature increase (universal gas law Mendeleev – Clapeyron ) . Hot gas is fed into the heat exchanger , called a condenser, where it is cooled , transferring its heat to water or air , and condenses – passes into a liquid state. Next, at high pressure fluid path set expansion valve reduces the pressure of the refrigerant. The compressor and the expansion valve closed hydraulic circuit divide into two parts: the high pressure side and the low pressure side . Passing through the expansion valve portion of the liquid evaporates and the temperature of the stream decreases. Continue reading
Unlike conventional heating systems based on the combustion of gas or liquid fuel , as well as direct transformation of electric energy into thermal energy in the heat pump is not consumed to produce heat , but only its transfer from the external environment . That’s what makes these systems an attractive solution for space heating and hot water at sites with limited energy resources.
Heat pumps ” Ekodan ” manufactured by Mitsubishi Electric, intended for individual heating and hot water town houses and similar buildings that do not have access to such a relatively cheap energy sources such as gas and liquid fuels , as well as substantially limited in the electrical power input .
Maximum heat output of a system of ” Ekodan ” is 14 kW, which is commensurate with modern heat loss of individual country houses. To increase the power provided an opportunity to cascade systems.
Heat pump ” Ekodan ” consists of two units : the outdoor unit , which is largely similar to the outdoor unit air conditioner, and indoor unit – hydronic heating water performing . Units are equipped with all the necessary control devices , control and regulation . Installation of such a system is no different from conventional air conditioning installation – cope with it any HVAC company . Excludes complex design heating and DHW system of separate components: a hydronic distribution system simply connects to the sanitary water use , as well as forward and reverse heating pipes . Continue reading
Earlier we said that there are some problems when working air conditioners in heating mode at low temperatures. And, of course , if the manufacturers have not overcome them , conditioners and would continue to buy mostly just because of the cooling mode , only occasionally including their heating on in the offseason. Next, we will explain what the technical solutions have allowed to become full conditioners heating appliances .
1. Low-temperature startup. We have already said that at certain temperatures compressor oil ceases to be dissolved in the coolant , and the problem is easy to solve. The first way is to install on the bottom of the compressor crankcase heater that runs at low temperatures. In the crankcase will always be a mixture of refrigerant and oil , and will not be “cold” start compressor. This solution is not very energy-efficient and widely used only for non-inverter , the so-called start-stop (On-Off) air conditioners. This solution enables you to omit the lower bound start the air conditioner to a level -15 ° C. Basically this solution used Chinese manufacturers of climatic equipment . The fact that the prices of start-stop air conditioners are low enough and complete masters of the market economy class are Chinese . Just this solution widely used in OEM brands of air conditioners, which are widely available on our market and are produced by the same Chinese manufacturers. By the way, this solution is so simple that it can be implemented on virtually all models of air conditioners. Any mounting HVAC company in its proposals has so-called low-temperature kits for ” upgrade ” the air conditioner on low-temperature start. Major branded manufacturers focus on more energy efficient equipment – inverters . Continue reading
The first system is a hybrid heat pump DAIKIN combines two well-proven in practice technology : heat pump ” air-water ” and gas condensing boiler , creating having high energy and economic efficiency of your home’s existing heating and hot water , which is an ideal replacement for gas boiler.
Annual efficiency of the hybrid heat pump DAIKIN Altherma approximately 35% higher than that of the gas condensing boiler , which is now considered the best of the proposed solutions on the market to replace old heating systems during the general renovation of the house.
For homeowners who want to replace their old boilers , the hybrid system – the obvious choice . It can be installed quickly and with minimum inconvenience since the inside of the house must perform a small amount of work . The indoor unit (like the hydraulic unit and gas boiler) located in the same space as the previously used gas boiler, radiators and uses the existing pipelines , which also reduces installation costs. In the long term, high efficiency can reduce energy consumption and leads to a reduction in costs.
Hybrid heat pump DAIKIN products is what sets us apart from other systems , since it could be part of any renovation project, regardless of the type of house and its location. The system is capable of supplying water at a temperature from 25 ° C to 80 ° C, which makes it suitable for any type thermal radiator including and existing radiators, and flexible enough to meet a wide range of the requirements for the heating and hot water systems . Continue reading
To maintain a comfortable temperature in the office premises , hotels medium sized trading floors of supermarkets in the best option is the so -called VRF-systems . They have a number of advantages, such as for central air conditioning systems , and before multi-split systems. VRF-systems are relatively compact and does not require a separate machine room for equipment .
One outdoor unit can support up to 64 internal , moreover it is possible to expand the system by adding additional internal blocks . The total length of all the communications system is significantly less than the total length of pipelines similar number of individual split systems . Thanks inverter compressor can achieve high rates of COP. It is also important that the VRF-systems significantly save energy . They do not require continuous maintenance and may be integrated into the central control system of any building.
One of the market leaders in VRF- systems company is Panasonic. In 2011, the company’s engineers have developed a system ECOi VRF, which showed the highest efficiency in 74 % of combinations . ECOi meets the most stringent requirements put forward by designers, architects , installers and homeowners . Consider the most important characteristics of this system on the example of the older model – VRF 2 -WAY ECOi ME1.
System belongs to the highest class of energy efficiency in industry EER4.04/COP: 4.56 ( 8 hp model ) . This is achieved through several innovations. Continue reading
According to the normative literature containing sanitary requirements for residential buildings , they should be provided with ventilation natural impulse . These are the most well-known all exhaust grilles in the kitchen, bathrooms and bathroom. A compensation exhaust air usually provide by entering the room apartment outside air through gaps in window openings , through open windows or skylights . There is such a thing as the outside air infiltration – the influx of outside air seeping through cracks external protections under the influence of wind and gravity. The beauty of this solution is that the optimal size of the window openings leaks and power headroom heating system we get a natural flow of fresh air , rich in oxygen , without additional construction and money.
In the calculations of ventilation in residential buildings sanitary norm of fresh air for each person in the room is usually considered 60 m3 / h per person or 3 m3 per 1 m2 of living space . Continue reading
Two years ago the management of the concern Systemair was decided to consolidate the production of all heating equipment under the brand Frico. On the one hand, it significantly expanded the possibilities, but on the other – significantly increased the responsibility for the possible failure of the local , including Ukrainian , markets.
At the same time the company’s strong growth came through acquisitions and air curtains manufacturers (Gelu, Shearflow, Tekadoor) in Europe . Partially their products poured into the main lineup, expanding its capabilities, partly dubbed the already existing model curtains Frico.
Thus, by the beginning of 2012 under the brand Frico produces more than 390 different air curtains . They were made in different countries, in different companies , with different technologies and different hardware components .
This circumstance prompted Systemair engineers to develop a new generation of air curtains that would connect a results of the most recent studies with new technological possibilities .
According to specialists, the diversity of the manufactured equipment could be without prejudice to the consumer to replace 150 models , making them the most versatile. Primarily developed product series PA3500 and PA4200, designed to replace the hangings series AS300/400 , AD300/400 and AG/AGV4000. Horizontal model with appropriate accessories can be connected in a continuous line , installed vertically and join column or placed in a suspended ceiling . Dimensions curtains from 1 to 3 m in increments of 0.5 m equipment available in versions without heating (A) , with electrical ( E) and hot water coolant with different parameters (WH, WL, WLL). Continue reading