ceiling air conditioner

Over the past few months we’ve noticed quite a bit of interest in geothermal heating and cooling amongst our site visitors, and in particular in geothermal heat pumps. We’ve also had many questions from people about exactly what they are and how/if they should consider them as an eco-friendly heating/cooling option. If this describes you, then read on - these systems ARE incredibly promising technologies to heat and cool your home, but they’re also more complicated than your typical AC or furnace unit. We’ll try to help clear the air!

We get into quite a bit of detail below, but before you get into that here’s a very quick summary of geothermal heat pumps :
# Geothermal (or ground source) heat pumps can be incredibly efficient, delivering 3-6x as much energy for heating and cooling as you use to power the equipment;
# They are in some ways a renewable energy system, since they use the heat contained in the earth to provide heating / cooling;
# They do require extensive installation work, including excavation or drilling to install subsurface pipes; and
# They are more expensive than traditional heating/cooling equipment, but the payback period is less than five years almost everywhere in the country due to their greater efficiency.

What is a Heat Pump ?

First things first, though: what exactly is a heat pump? Well, just like it sounds, a heat pump moves heat from one place to another rather than creating heat or cooling by burning a fuel (like a furnace or boiler). They do this by taking advantage of the fact that liquid refrigerants absorb huge amounts of heat when they turn into gas via evaporation, and release that same heat when they are condensed back into liquids.
The most common kind of heat pump, called an air source heat pump , uses the energy in outdoor air to heat and cool. To cool a warm space, a heat pump evaporates the liquid refrigerant in copper coils indoors and condenses it (via a compressor) in similar coils outdoors. To heat a cold room, a valve is activated that reverses the process: the gaseous refrigerant is condensed indoors where it gives off heat, and it evaporates in the outdoor coils, picking up heat from outdoors in the process. Air conditioners and refrigerators use the same exact process to deliver their cooling performance.

Why are they such great heating and cooling options? For one, heat pumps can be incredibly efficient: because they move rather than create heat, they can often deliver 3-4x more energy into your home than you use to power the heat pump (high efficiency air conditioners have the same benefit). Ceiling air conditioner , heat pumps also provide both heating and cooling, meaning you don’t need two separate systems that only get used for half the year.

With all of these benefits, you might expect to see air source heat pumps everywhere, so what’s the catch? Well, because they are more complicated than typical air conditioners and furnaces, they’re a bit more expensive up front. And, they work best in relatively moderate and humid climates: the greater the difference between the indoor and outdoor temperatures, the harder they have to work. Once outdoor temperatures drop below 40 degrees or so, heat pumps are no longer efficient as heaters and you need some kind of auxiliary heating. In very hot climates with low heating needs, air source heat pumps are no more efficient than air conditioners but are more expensive.

The Joys of Geothermal

Fortunately, there’s a great way around these limitations on traditional air source heat pumps. In even the most extreme climate regions, the temperature several feet underground is between 45 and 75 degrees Fahrenheit. Enter the geothermal heat pump (also called GeoExchange heat pumps and ground source heat pumps). These heat pumps circulate a fluid through piping buried in the ground, discharging heat to the ground in summer and pulling it from the ground in winter. The heat pump coils are in contact with this fluid rather than the outside air as in a standard heat pump, thereby avoiding the huge temperature swings of our atmosphere. Geothermal heat pumps can be incredibly efficient, delivering from 3-6x the amount of energy used to power the pump’s compressor and fans/pumps.

There are several options for installing a ground source heat pump. The choice of which one makes sense in your area involves many factors, such as how much land you have available, what the underground conditions are like, and the skill / experience of installers in your area. As you scan these options you might think “wow, these must be expensive!”, but due to the incredible energy efficiency of these systems payback periods can often be less than five years.

from:lowimpactliving

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• 1. High efficiency with R410Arefrigerant,Japanese brand compressor and optimized design.
• 2. Intelligent design for easy maintenance of whole unit and replacing filter.
• 3. Special design for cold winter and strong heating in super low temperature as north Europe.
• 4. Phone call remote control provide the most convenient operation for the consumer.
• 5. Wide angle of air flow, Auto swing assure the comfortable feeling.
• 6. Classic and Elegant appearance for beautiful decoration.
• 7. Self trouble diagnosis for convenience of maintenance and trouble solving.

Floor Fan Coil

1.Diversity of Floor Fan coils suitable for different requirement.
2.Floor Fan coils  with super thin and elegant design same model as Daikin.
3.Small dimensions with compact structure for ceiling Safe and reliable, long service life and low noise.
4.High performance coils by USA OAK facilities.
5.I&O connetion:3/4".
6.Power supply:220V-230V/1PH/50HZ.
7.Capacity:18K-60K btu.

from:china-heat-pump

A fan coil unit (FCU) is a simple device consisting of a heating or cooling coil and fan. It is part of an HVAC system found in residential, commercial, and industrial buildings. Typically a fan coil unit is not connected to ductwork, and is used to control the temperature in the space where it is installed, or serve multiple spaces. It is controlled either by a manual on/off switch or by thermostat.

Due to their simplicity, fan coil units are more economic to install than ducted or central heating systems with air handling units. However, they can be noisy because the fan is within the same space. Unit configurations are numerous including horizontal (ceiling mounted) or vertical (floor mounted).

A fan coil unit may be concealed or exposed within the room or area that it serves.

An exposed fan coil unit may be wall mounted, freestanding or ceiling mounted, and will typically include an appropriate enclosure to protect and conceal the floor fan coil itself, with return air grille and supply air diffuser set into that enclosure to distibute the air.

A concealed fan coil unit will typically be installed within an accesible ceiling void or services zone. The return air grille and supply air diffuser, typically set flush into the ceiling, will be ducted to and from the fan coil unit and thus allows a great degree of flexibility for locating the grilles to suit the ceiling layout and/or the partition layout within a space. It is quite common for the return air not to be ducted and to use the ceiling void as a return air plenum.

The coil receives hot or cold water from a central plant, and removes or adds heat from the air through heat transfer. Traditionally fan coil units can contain their own internal thermostat, or can be wired to operate with a remote thermostat. However, and as is common in most modern buildings with a Building Energy Management System (BEMS), the control of the ducted fan coil unit will be by a local digital controller or outstation (along with associated room temperature sensor and control valve actuators) linked to the BEMS via a communication network, and therefore adjustable and controllable from a central point, such as a supervisors head end computer.

Fan coil units circulate hot or cold water through a coil in order to condition a space. The unit gets its hot or cold water from a central plant, or mechanical room containing equipment for removing heat from the central building's closed-loop. The equipment used can consist of machines used to remove heat such as a chiller or a cooling tower and equipment for adding heat to the building's water such as a boiler or a commercial water heater.

Fan coil units are divided into two types: Two pipe fan coil units or Four pipe fan coil units . Two pipe fan coil units have one supply and one return pipe. The supply pipe supplies either cold or hot water to the unit depending on the time of year. Four pipe fan coil units have two supply pipes and two return pipes. This allows either hot or cold water to enter the unit at any given time. Since it is often necesary to heat and cool different areas of a building at the same time, due to differneces in internal heat loss or heat gains, the four pipe fan coil unit is most commonly used.

Fan coil units may be connected to piping networks using various topology designs, such as "direct return", "reverse return", or "series decoupled". See ASHRAE Handbook "2008 Systems & Equipment", Chapter 12.

Depending upon the selected operating conditions, it is very likely that the cooling coil will be designed to de-humidify the entering air stream, and as a by product of this process, it will at times produce a condensate which will need to be carried to drain. The floor fan coil will contain a purpose designed drip tray with drain connection for this purpose. The simplest means to drain the condensate from multiple fan coil units will be by a network of pipework laid to falls to a suitable point. Alternatively a condensate pump may be employed where space for such gravity pipework is limited.

Speed control of the fan motors within a fan coil unit is effectively used to control the heating and cooling output desired from the unit. This is normally acheived by manually adjusting the tappings on an AC transformer supplying the power to the fan motor. Typically this is adjusted at the commissioning stage of the building construction process and is therefore set for life. However alternative means of external speed control by electronic means through the BEMS can be provided if so required. Fan motors are typically AC type motors but more recently DC motors have been made available by some manufacturers, and can potentially offer significant energy savings.

Duct fan coils are typically used in spaces where economic installations are preferred such as unoccupied storage rooms, corridors, loading docks.

In high-rise buildings, fan coils may be stacked, located one above the other from floor to floor and all interconnected by the same piping loop.

Fan coil units are an excellent delivery mechanism for hydronic chiller boiler systems in large residential and light commercial applications. In these applications the fan coil units are mounted in bathroom ceilings and can be used to provide unlimited comfort zones - with the ability to turn off unused areas of the structure to save energy.

In high-rise residential construction, typically each fan coil unit requires a rectangular through-penetration in the concrete slab on top of which it sits. Usually, there are either 2 or 4 pipes made of ABS, steel or copper that go through the floor. The pipes are usually insulated with refrigeration insulation, such as acrylonitrile butadiene/polyvinyl chloride (AB/PVC) flexible foam (Rubatex or Armaflex brands) on all pipes or at least the cool lines.

A unit ventilator is a fan coil unit that is used mainly in classrooms, hotels, apartments and condominium applications. A unit ventilator can be a wall mounted or ceiling hung cabinet, and is designed to use a fan to blow air across a coil, thus conditioning the space which it is serving.

from:wiki

Window and through-wall units
Room air conditioners come in two forms: unitary and packaged terminal PTAC systems. Unitary systems, the common one room air conditioners, sit in a window or wall opening, with interior controls. Interior air is cooled as a fan blows it over the evaporator. On the exterior the air is heated as a second fan blows it over the condenser. In this process, heat is drawn from the room and discharged to the environment. A large house or building may have several such units, permitting each room be cooled separately. PTAC systems are also known as wall split air conditioning systems or ductless systems. These PTAC systems which are frequently used in hotels have two separate units (terminal packages), the evaportive unit on the exterior and the condensing unit on the interior, with tubing passing through the wall and connecting them. This minimizes the interior system footprint and allows each room to be adjusted independently. PTAC systems may be adapted to provide heating in cold weather, either directly by using an electric strip, gas or other heater, or by reversing the refrigerant flow to heat the interior and draw heat from the exterior air, converting the air conditioner into a heat pump. While room air conditioning provides maximum flexibility, when cooling many rooms it is generally more expensive than central air conditioning.

Evaporative coolers
In very dry climates, evaporative coolers are popular for improving comfort during hot weather. This type of cooler is the dominant cooler used in Iran, which has the largest number of these units of any country in the world, causing some to referring to these units as "Persian coolers."  An evaporative cooler is a device that draws outside air through a wet pad, such as a large sponge soaked with water. The sensible heat of the incoming air, as measured by a dry bulb thermometer, is reduced. The total heat (sensible heat plus latent heat) of the entering air is unchanged. Some of the sensible heat of the entering air is converted to latent heat by the evaporation of water in the wet cooler pads. If the entering air is dry enough, the results can be quite comfortable; evaporative coolers tend to feel as if they are not working during times of high humidity, when there is not much dry air with which the coolers can work to make the air as cool as possible for dwelling occupants. Unlike air conditioners , evaporative coolers rely on the outside air to be channeled through cooler pads that cool the air before it reaches the inside of a house through its air duct system; this cooled outside air must be allowed to push the warmer air within the house out through an exhaust opening such as a open door or window.

These coolers cost less and are mechanically simple to understand and maintain.
An early type of cooler, using ice for a further effect, was patented by John Gorrie of Apalachicola, Florida in 1842. He used the device to cool the patients in his malaria hospital.

Portable air conditioners
Portable air conditioners (or PACs) are moveable units that can be used to cool a specific room in a home and do not require permanent installation. Warm air in the room is drawn in through inlets on the portable air conditioner. The air is circulated through the unit and is cooled by evaporator coils with refrigerant running through them and then blown out through the front. Remaining hot air in the unit is expelled and vented through the back with an exhaust hose. All portable air conditioners require exhaust hoses for venting.

Single Hosed Units
A single hosed unit has one hose that runs from the back of the portable air conditioner to the vent kit where hot air can be released. A single hosed portable air conditioner can cool a room that is 475 sq. ft. or smaller and has at most a cooling power of 12,000 BTUs.

Dual Hosed Units
Dual hosed units are typically used in larger rooms. One hose is used as the exhaust hose to vent hot air and the other as the intake hose to draw in additional air (usually from the outside). These units generally have a cooler power of 12,000-14,000 BTUs and cool rooms that are around 500 sq. ft. The reason an intake hose is needed to draw in extra air is because with higher BTU units, air is cycled in large amounts and hot air is expelled at a faster rate. This creates negative air pressure in the room, and the intake hose stabilizes the room's air pressure.

Split Units
Portable units are also available in split configuration, with the compressor and evaporator located in a separate external package and the two units connected via two detachable refrigerant pipes, as is the case with fixed split systems. Split portable units are superior to both single and dual hosed mono-portable units in that interior noise and size of the internal unit is greatly reduced due to the external location of the compressor, and no water needs to be drained from the internal unit due to the exterior location of the evaporator.

A drawback of split portable units compared with mono-portables is that a surface exterior to the building, such as a balcony must be provided for the external compressor unit to be located.

Unlike window ACs the split AC does not have an option of exchange of indoor and outdoor air.

Heat and Cool Units
Some portable air conditioner units are also able to provide heat by reversing the cooling process so that cool air is collected from a room and warm air is released. These units are not meant to replace actual heaters though and should not be used to cool rooms lower than 50 °F (10 °C).

Central air conditioning
Central air conditioning, commonly referred to as central air (U.S.) or air-con (UK), is an air conditioning system which uses ducts to distribute cooled and/or dehumidified air to more than one room, or uses pipes to distribute chilled water to heat exchangers in more than one room, and which is not plugged into a standard electrical outlet.

With a typical split system, the condenser and compressor are located in an outdoor unit; the evaporator is mounted in the air handler unit. With a package system, all components are located in a single outdoor unit that may be located on the ground or roof.

Central air conditioning performs like a regular air conditioner but has several added benefits:

    * When the air handling unit turns on, room air is drawn in from various parts of the building through return-air ducts. This air is pulled through a filter where airborne particles such as dust and lint are removed. Sophisticated filters may remove microscopic pollutants as well. The filtered air is routed to air supply ductwork that carries it back to rooms. Whenever the air conditioner is running, this cycle repeats continually.

    * Because the condenser unit (with its fan and the compressor) is located outside the home, it offers a lower level of indoor noise than a free-standing heat pums unit.

Mini (Small) Duct, High Velocity
A central air conditioning system using high velocity air forced through small ducts (also called mini-ducts), typically round, flexible hoses about 2 inches in diameter. Using the principle of aspiration, the higher velocity air mixes more effectively with the room air, eliminating temperature discrepancies and drafts. A high velocity system can be louder than a conventional system if sound attenuators are not used, though they come standard on most, if not all, systems.

The smaller, flexible tubing used for a mini-duct system allows it to be more easily installed in historic buildings, and structures with solid walls, such as log homes. These small ducts are also typically longer contiguous pieces, and therefore less prone to leakage. Another added benefit of this type of ducting is the prevention of foreign particle buildup within the ducts, due to a combination of the higher velocity air, as well as the lack of hard corners.

from:wiki