Air Heating Systems – Advantages and Disadvantages

29
Aug

Forced air is by far the most popular home heating appliance in North America which provided warmth to the whole building; one room to multiple. Around 90% of homes in North America make use of a central forced air system to circulate warm air in their apartment. Forced air systems consist of a furnace with a fan to heat and move air, supply ducts to carry warm air to each room, return ducts to pull cool air back to the furnace, and a centrally located thermostat for controlling the functioning of the furnace.

A forced-air central heating system is one which uses air as its heat transfer medium. These systems rely on ductwork, vents, and plenums as means of air distribution, separate from the actual heating and air conditioning systems. The return plenum carries the air from several large return grills (vents) to a central air handler for re-heating. The supply plenum directs air from the central unit to the rooms which the system is designed to heat. Regardless of type, all air handlers consist of an air filter, blower, heat exchanger/element/coil, and various controls. Like any other kind of central heating system, thermostats are used to control forced air heating systems.

There are 3 different approaches to the autonomous heating system or forced air central heating system. They are as follows

– Water heating system;
– Air heating system;
– Radiant heating system.

In recent year, Air heating system has gain popularity when compared to classical water heating system and radiant heating system

Advantages Of Air Heating System

Cost Effective –

Operational cost and purchase cost of the appliances is much affordable as compared to other automatic heating system

Fast Heating Aptitude –

The high speed of constant air movement inside the heated room provides a quick and uniform heating of the entire volume.

Disadvantage of Air Heating System

Lower Efficiency.

Sure there are 95% efficient forced air systems out there but the number does not tell you the whole truth. By the time the air reaches its destination it has cooled off already and this may be an issue if ducts go through unfinished basements or crawlspaces.

Cold and hot spots.

There will be no room will have the same temperature. Even within the same room, there will be colder spots or warmer spots. In the summer, it can observe that the floors will be colder whereas the ceilings will be warm

Dust is being blown around.

This is a major nuisance. No matter how often you clean and vacuum there is always some dust building up and forced air systems are great in catapulting it into your throat and around the house.

Noise

No matter how well a system is tuned and built, there is always some noise.

Air drafts.

A good A/C system may be relatively quiet compared to one that isn’t engineered properly; however, air drafts are a major problem.

Multi zone Industrial and Commercial Air conditioners

11
Aug

Industrial air conditioners are installed today in all enterprises, factories, manufacturing plants, business centers, shopping halls, sports complexes, large area (over 250 sq. M). Industrial air conditioners provide uninterrupted air conditioning, refrigeration and heating. Features industrial air conditioners – a complexity of use, energy efficiency, the cost of equipment. Industrial air conditioners have a resource 20 – 30 years of operation.

Multi zone system allows to condition several rooms and even the whole building. Each room is set the indoor unit and is supported by individual micro climate. Compared with the installation of individual air conditioners multi-zone air-conditioning system can save money, space, installation time. Multi-zone air conditioning units can be controlled centrally or individually. Designed for buildings containing a few (or a few dozen) areas with different requirements to the air.

Multi zone air conditioning system – profitable, convenient, safe

More than thirty years ago (1982) Daikin Company made a revolutionary breakthrough in the field of HVAC equipment by launching multi-zone air-conditioning system – VRV, which means “Variable refrigerant volume.” Since the company has patented, not only the system itself but also the abbreviation of VRV, as a trademark, other companies began to produce such equipment, began to use the name of the VRF «variable refrigerant flow.” However, in both cases we are talking about one and the same principle of operation of multi-zone air-conditioning.

Features multi-zone systems

  • Multi-zone air-conditioning system – it is the climate system inverter, which is installed in buildings with a large number of premises, providing a separate temperature control in the individual zones.
  • The multi zone system includes one outdoor unit and a lot of internal. The outdoor unit is connected to the internal pipework. Amount of internal blocks, drop their height relative to the outdoor unit, performance, pipe length are defined by the model and brand of the selected multi-zone air conditioning.
  • Multi zonal air conditioning systems use a modular design, so their installation are taken into account wishes of the customer in terms of the number of indoor units and their types (duct, cassette, floor, wall, ceiling).
  • Multi-zone air-conditioning system can be operated to cool the air in the same room at the same time, warming in the other, producing just enough cold and consuming as much energy as necessary to indoor units. Outdoor unit operating mode changes with the load of indoor units.
  • Control each indoor unit is carried out from the local console or centrally from the control center. Temperature parameters given in every room maintained at a constant level with high accuracy.
  • The performance of a number of multi-zone systems can serve the high-rise buildings.

6 questions about underfloor heating

11
Aug

Warm floors are increasingly part of our lives. Someone “felt” warm floors, being at a party, and now dreams of a similar system at home. Someone found them in the bathroom, I liked it, and decided to do around the house. And someone had just heard about underfloor heating, and does not know if he needed it. We will answer your questions.

1.  Is warm floor safe for kids?

Underfloor heating is completely safe for children. It can be easily installed in the children’s room. Moreover, even with an open window in the room there is no draft. You can leave the kids play on the bare floor. However, if you choose an electric radiant floor heating, you should purchase and install is a two-core cable systems. In contrast to the single-core, they are more expensive. But the level of electromagnetic radiation in two-wire electrical floors so small that it has no effect and does not bring any harm.

2. Is it possible to lay floor heating in the bedroom?

It is believed that the warm floor cannot be laid in the bedroom. Supposedly heated air coming from the bottom, a negative impact on healthy sleep. In fact it is not. If exposed to moderate temperature, then sleep will be quite comfortable. Modern thermostats are equipped with timers, daily and weekly programming, so at night the warm floor temperature can be set lower by 2-3 degrees than in the day.  This will not experience discomfort during sleep and still walk on the floor without slippers.

3. Is it true that the underfloor heating system improves the health of asthmatics and allergy sufferers?

Uniform distribution of heat from the floor heating prevents burning of dust, the air drainage. Also underfloor heating to prevent the emergence and spread of mold and mildew. In addition, no radiator dust much less flying across the room, leaving the air clean. If the home is equipped and the system of underfloor heating and ventilation system, there is no doubt, it will be easier to breathe. People with asthma or allergies, begin to feel better.

4. Is it possible to install a warm floor under furniture, under laminate, a parquet floor, under the carpet?

Underfloor heating is spread only on the free space (under the fixed furniture and appliances to mount the floor heating is not recommended). Special electric floor heating for wood can be installed under laminate and parquet board. On the radiant floor heating is also possible to lay laminate or flooring, but it is important that these coatings were of high quality. Carpets and rugs lay undesirable. They impede the free flow of heat across the room.

5.  Can I install the underfloor heating in showers and bathrooms?

And the water, and electric floor heating can be installed in bathrooms and shower rooms. Electrical cables are protected from short circuits. Underfloor heating will forget about the “cold tile”, quickly dry the wet floor, and make it less slippery and dangerous.

6. Can I make a warm floor in the balcony on the balcony? And if so, how – water or electric?

In an apartment building with a central radiant floor heating system cannot be installed, an electric only. In this case, the heating cable or heating mat can be laid on the balcony or loggia. However, it is necessary that the balcony was sufficiently insulated, especially the floor and ceiling. In a private house permissible conduct electric underfloor heating on the balcony or loggia. Water heating in extreme cold can freeze. Therefore, in the cottages should apply anti-icing system.

Ventilation Unit: Advantages and Disadvantages.

11
Aug

What is forced ventilation? How it is done and what is required? In our review – all kinds of equipment for ventilation systems, pros / cons, characteristics. Tell me what to look for when choosing what to buy venting units

Ventilation system in an apartment or in a house:

If exhaust ventilation is usually designed and laid at the stage of building a house, the plenum often left unattended builders. It is assumed that the flow should be carried out through the open windows, leaky structure. But most of the houses are insulated which do not let the air to flow. As a result, there are problems arrive, without forced ventilation which works much worse or does not work at all.
Ventilation devices are capable of ensure the house quiet, clean, comfortable and fresh air.

1: Window flaps.

Mounted on PVC windows. The advantages: cheap, invisible in the interior, installed quickly and easily, does not require drilling holes in the wall.
Disadvantages: window flaps are usually not equipped with filters and sound insulation, are not protected from freezing, moreover manufacturers specify that the window ventilators are functioning only with good extract.

2:Wall intake valves

These devices are mounted on the wall. In fact, they are adjustable window. Equipped with thermal insulation layer, filter against coarse dust and insects. What is important to consider when choosing a valve? For effective ventilation in the apartment or in a house must be a sufficient number of the incoming air.

Disadvantages: of air-supply valves – in extreme cold can pass the cold, and in summer (at the same temperature of air inside and outside) cease to provide the inflow

3: Ventilators

Advantages of ventilators – the ability to perform forced ventilation at any time of the year (as there are fans, forced pounding the air), the presence of the ceramic heater, performing the heating of the cold stream from the street, high performance, the ability to install high-quality filters, providing multi-stage cleaning system from dust, exhaust and other contaminants. What is important to consider when choosing? The volume of incoming air, noise, filter class, power consumption, and size of the device.
Disadvantages: with the installation of the ventilator increases the cost of electricity (especially in cold weather).

4: Supply and exhaust valves recovery

This is not entirely forced ventilation, because the devices have not only the influx, and the hood. They can operate with a ventilation system as well as regular air inlets. Their main advantage – the presence of the built-in heat exchanger, allowing to warm air without energy. Almost invisible in the interior. When choosing-exchanger valve is necessary to take into account the capacity of the device, air flow, noise level, country of origin, the period of warranty, the build quality.

Disadvantages: the heat exchanger valves – not as effective as in ventilation installations, reheating is not provided, so the frost can pass cold air.

5: Fresh air ventilation systems.

This is ideal ventilation for the house, apartment or office. The interior ventilation is invisible (hidden under the ceiling ducts). At the same time the performance of the device will be enough to ensure effective ventilation throughout the house, apartment or office

Disadvantages: complexity of installation work – need to lay ducts, installation of the system is possible only before the final finish of the room. You cannot save on electricity

Basic Modern Air Conditioner Functions

06
Aug

Air conditioners can be found in all price categories with a similar set of features and modes.

Infrared remote control with LCD display used to manage all the modern air-conditioner that allows you to set the mode of operation of a split system, the desired temperature, programming the timer to turn on / off the air conditioner, etc.

As a rule, the number of functions of an economy class air conditioners do not differ much from the models top price category. Reason such harmonization is that to provide added functionality is not required to modify or complicate the design of the air conditioner, only need to reprogram the microcontroller controlling the operation of the air conditioner and add the buttons on the remote control.

Because of this producers can inexpensively add new modes conditioners or additional functions and successfully build on their basis of their advertising campaigns. As a result, in terms of affordability, the difference between the air-conditioned different price groups are often absent.

Less common features that really lead to a rise in price of air conditioning, as their implementation requires changes in its structure. For example, the built-in motion sensor saves energy and temperature sensor in the control panel allows you to maintain the set temperature of the indoor unit is not in the area, and where is the remote. How these functions are needed and whether or not for them to pay for the air conditioning to you.

Major modes and air-conditioning functions:

Cooling and heating 

The main modes of the air conditioner used for air conditioning and heating.

Ventilation

The operating mode in which only works indoor fan, without including the compressor. Used for even air distribution throughout the room and can be used, for example, in winter, when warm air from heaters or central heating batteries accumulates on the ceiling and the floor is cold.

Automatic mode

In this mode, the air conditioner itself controls the selection of the operating mode (cooling, heating or ventilation) to maintain a comfortable temperature.

Dehumidification

The dehumidification air conditioner reduces the humidity. Generally speaking, dehumidification is always accompanied by its cooling. The warm air comes into contact with a cold heat exchanger (radiator) of the indoor unit, resulting in a heat exchanger to condense moisture, which is discharged through the drain hose. The same principle works all modern air driers. Therefore, in the dehumidification mode, the air conditioner operates in the same manner as in the cooling mode, only the room temperature is reduced by no more than 1 ° C.

Air purification.

To clear the air before the heat exchanger of the indoor unit set one or more filters. The primary air conditioner filter for cleaning the air from large dust. This filter is a conventional fine mesh and protects not only the inhabitants of the conditioned space as the interior of the air conditioner. To clean this filter enough wash it with warm water.

Setting the temperature.

For heating and cooling modes can be controlled by the air temperature to within 1 ° C in the range of 16-18 to 30 ° C. Typically, the temperature sensor is installed in the indoor unit, but some models have an additional sensor, built-in remote control (function «I Feel»). In some models also have built-in indoor unit remote infrared thermometer that measures the temperature of the surrounding surfaces (function «I See»).

Fan speed

The indoor unit fan can rotate at different speeds, respectively, changing the amount of air passing through the internal unit (this option is called the air output or “pumping”the air conditioner is measured in m³ / h). Typically, the fan is from 3 to 5 fixed speeds plus auto mode.

The direction of air flow

The direction of air flow generated by the indoor unit can be adjusted vertically by means of horizontal plates (louver) having fixed positions 5-7. In cooling mode, the flow is usually directed horizontally along the ceiling to the cold air did not get to the people. In heating mode, the air flow is directed downwards, because hot air is lighter than cold air and rises upwards. In addition, the blinds can automatically swing up and down, evenly distributing the flow of air around the room.

The timer on and off

With the 24-hour timer, you can set the auto power on and off the air conditioner, for example, can include air-conditioning for an hour before returning to work.

Night mode

After the inclusion of the air-conditioning mode, sets the minimum speed of the fan (to minimize noise) and gradually increases (in cooling mode) or decreases (in heating mode) at a temperature of 2-3 degrees for several hours. It is believed that such temperature conditions are optimal for sleeping.

Panasonic WhisperGreen Select – Best Indoor Air Quality Solution

05
Aug

Select Panasonic is a best solution to maintain indoor air quality, which reconstructs the ventilation industry with a new set of functions that allow you to customize and install more than 250 different configurations.

It has a speed switch Integrated Pick-Flow to select the desired air flow (50-80-110 CFM). Plug and play modules also contribute to the further expansion of the setting.

It has a DC motor technology and mounting Smart Flow Flex-Z Quick angle used in accordance with the latest codes and industry standards.

With Smart Flow function, when the fan faces static pressure, the speed is automatically increased to provide optimum CFM output. This feature provides confirmation that the installer does not have to worry about damage to the fan performance.

Boilers: Various Types and Classification

23
May

 

In today’s energy work a variety of types of boilers. They can be classified by type of fuel, coolant type, accommodation type, level of mechanization. The specific type of boiler is selected depending on the goals and objectives, operating conditions and customer requirements.

  1. Fuel type
  • Gas: The advantage of this kind of boiler is that the gas – one of the most economical and environmentally friendly fuels. Gas boiler does not require complicated and cumbersome equipment fuel and slag removal, and can be fully automated.
  • Fuel oil: These boilers can run on waste oil, fuel oil, diesel oil. They quickly put into operation, do not require special permits, the connection negotiation, obtaining gas limits (as opposed to gas).
  • Solid: To the solid fuel concerns coal, peat, wood, pellets and briquettes from waste wood processing and agriculture. The advantage of this type of boiler is the availability and low price of fuel, but it requires the installation of fuel and ash handling systems.
  1. Coolant type
  • Steam:  In such a boiler heat carrier is steam, which is used mainly for manufacturing processes in industrial plants.
  • Water: This type of boiler is designed for heating and hot water supply of residential buildings, industrial and public facilities. The coolant is water, heated to +95 +115 ° C.
  • Combined: In these boilers are placed as steam and hot water boilers. Hot water is used to cover the load for hot water, heating and ventilation, and the steam is supplied to provide the technological needs of the enterprise.
  • Diathermic oil: In this boiler is used as a coolant in the high-temperature organic liquid, the temperature of which can reach +300 ° C.
  1. Accommodation type
  • Modular: This type of boiler is becoming increasingly popular in Russia in recent years, thanks to many advantages in comparison with stationary boilers: fastest time of installation and commissioning, factory-assembled modules, the ability to increase capacity by adding units, battery life, high efficiency, mobility. Depending on the placement of block-modular boiler can be detached, and attached, integrated, roof, basement.
  • Stationary: Stationary boilers are usually built when the required power exceeds 30 MW, or the construction of a modular boiler for some reason impossible. Stationary boilers distinguished by major building and construction (foundations, walls and partitions, roof). Installation of equipment on site is performed.
  1. The level of mechanization

Depending on the degree of mechanization / automation processes are the following types of boiler:

  • Hand: Small boilers can be equipped with boilers, in which the fuel supply is performed manually by operators. The fuel is supplied to the boiler room truck or in some cases from the outside through a loading hopper. The ash and slag from the ash hopper and are removed manually by the operator and exported outside the boiler room via trolley.
  • Mechanized: Modern boilers are equipped with solid mechanization, significantly facilitate the work boiler operator. Fuel supply by means of conveyors or skip hoists. Coal is pre-processed. The ash and slag may be removed by various methods – mechanical, hydraulic, pneumatic or a combination thereof.
  • Automated: This type of boiler assumes full automation and minimal presence of the human factor. Fully automated, as a rule, gas boiler.

 

Energy-saving technologies in Modern chillers

23
May

 

In the development of modern HVAC equipment of particular importance is given to the problem of energy conservation. The amount of energy consumed by the equipment during the annual life cycle is one of the main criteria for decision-making when considering proposals submitted to tender. To date, a significant potential for energy efficiency is the development and establishment of climatic equipment, able to cover as precisely as possible the load schedule in constantly changing conditions

At the same time, the daily schedule of excess heat is also uneven pronounced maximum. Traditionally, chillers with capacity of 20-80 kW installed two identical compressors and make the two independent refrigerant circuits. As a result, the machine can operate in two modes at 50% and 100% of its rated capacity. The new generation of chillers with cooling capacity from 20 to 80 kW allows you to perform three-stage capacity control. In this case, the total refrigerating capacity is distributed among the compressors in a ratio of 63% and 37%.

The new generation of chillers both compressors are connected in parallel and operate on a single refrigerant circuit, that is, have a common condenser and evaporator. This arrangement significantly increases the energy conversion efficiency (KPI) of the refrigerant circuit when operating at part load. For such chillers at 100% load and outdoor temperature of 25 ° C KPE = 4, and at the 37% CPE = 5. Given that 50% of the time the unit is working with a load of 37% of this gives a considerable energy saving.

Microprocessor controllers

Microprocessor controllers are set for the effective implementation of new solutions in the chillers, which allow:

  • control all the operating parameters of the equipment;
  • adjust the set point temperature of the water at the outlet of the unit in accordance with the parameters of the outside air, process or commands from a centralized control system (supervisor);
  • selects the optimal power control step;
  • In the case of real need to quickly and effectively perform a defrost cycle (for heat pump models).

As a result, an automatic compressor to minimize the short-inclusions, optimize working hours of compressors and the adjustment parameters of the water leaving the chillers in accordance with real needs. As on average, it takes place during the day only 22 incorporating compressor while the compressor includes conventional chiller 72 times.

Another important advantage which enables the use of new chillers, is that eliminates the need for installation of bulky storage tanks and built into the body of the unit circulation pump eliminates the need for an additional pump station.

Energy-efficient gas compressor

As you know, for the accurate performance load curve of the chiller is very important type of used compressors. Traditionally, large capacity chillers used piston or rotary screw compressors. The reciprocating compressor has many moving parts and, consequently, low efficiency due to large frictional losses. In the operation of reciprocating compressors there is a high level of noise and vibration, as well as there is a need for their regular maintenance. Screw compressors, in turn, have a complex structure, and as a result, very high cost. Production of screw compressors is low-profit.

Service of such compressors consuming and requires highly skilled personnel. In recent years, the market of new type of compressor SCROLL appeared that lack specific deficiencies reciprocating and screw compressors. Scroll-compressors have a high energy efficiency, low noise and vibration, and require no maintenance. This type of compressors is simple in construction, is very reliable and, at the same time is inexpensive. However, performance Scroll-compressors usually does not exceed 40 kW.

Selection of Industrial Refrigeration Equipment

23
May

Choosing industrial refrigeration equipment for enterprises, primarily necessary to define what tasks you are going to put in front of him and try to take into account all the factors that will continue to affect the performance of the system cooling. Such options may be few, but you need to choose the most optimal.

To correctly determine the choice of refrigeration equipment must always take into account the system parameters such as:

  1. extreme heat
  2. the amount of heat in a time interval,
  3. Hydraulic resistance, as well as pre-agree on the heat dissipation and duplication systems.

As practice shows, in most cases, for a rational use of the equipment necessary to install more than one cooling system, and more. This is because the performance of the equipment at different times can be different: for example, a higher weekdays and weekends – lower. In such cases it is sufficient to install a small, which will increase the wear resistance of the cooling system and save on operating costs.

When choosing a pump to circulate the fluid, you will need to take into account the following factors: the diameter of the pipes, liquid lifting height and its distance from the energy source.

If the result of calculating the cost of refrigeration equipment coincides with the cost of downtime of the equipment, then we can consider the option of picking system spare equipment. In this case the two systems communicate with each other by the control unit, which in the case of an emergency or an unexpected stop of the main equipment will automatically turn spare.

Chiller Purchasing equipment with a powerful electric drive, you should consider that it has a limited number of starts per hour and running at the same time in the most unfavorable mode. Starting currents in this case is increased tenfold, and increases heat power cable is hundreds of times.

In contrast to the rated speed, increasing the current strength affects the torque, which increases at the start of dynamic impact on the shaft, bearings and couplings. Now, having seen the consequences of such a choice, you can imagine how many are able to serve in a similar refrigeration equipment operating conditions.

Absorption chiller – Advantages

23
May

Absorption chillers – a very promising field of refrigeration, is becoming more widely used because of the pronounced tendency to modern power management. The fact is that for absorption chillers main source of energy is not electricity, and waste heat that inevitably occurs in plants, factories and so on. N. And irrevocably thrown into the atmosphere, whether it is hot air, cooling air hot water, and others.

The main advantages of absorption chillers:

  1. The ideal solution for creating tri-generation enterprise. Tri generation complex – a complex allows to date as much as possible to reduce the cost of electricity, hot water, heating and cooling for the enterprise through the use of its own cogeneration power plant in conjunction with an absorption chiller;
  2. Long service life – within 20 years before the first major overhaul;
  3. Low cost of produced cold, cold is produced almost free of charge
  4. Reduced noise and vibration as a result of the lack of compressors with electric motors, as a consequence – quiet operation and high reliability;
  5. The use of refrigeration / heating units with the flame of a gas generator of direct action eliminates the boilers to be used in conventional installations. This reduces the initial cost of the system and makes absorption chillers competitive compared to conventional systems, which utilize boilers and chillers;
  6. Maximizing energy savings during periods of peak demand. In other words, do not consume electricity for the production of cold / heat absorption chillers do not overload the power supply enterprise, even in times of peak demand;
  7. There is the possibility of combining in the district steam systems with efficient refrigeration unit of double effect;
  8. It is possible to load balancing in conditions of maximum efficiency in the cooling mode. The device handles the critical load in the cooling mode, with minimal power consumption through the use of refrigerants with a flaming gas generator direct effect or generator with steam heating;
  9. It allows the use of emergency generators at the power, as energy consumption in absorption chillers is minimal when compared with electric refrigeration units;
  10. Security for the ozone layer does not contain refrigerants that deplete the ozone. Cooling is carried out without the use of refrigerants containing chlorine;
  11. Minimizes the overall impact on the environment as the consumption of electricity is reduced and the gas causing the greenhouse effect and global warming as a consequence.