Universal
- Central air conditioners
- Rooftop air conditioners
- Supply-and-exhaust units
- Crane and vehicle air conditioners
- Mobile and packaged air-conditioners
- Air-conditioners for electric control rooms, special and process air-conditioners
- Air-conditioners for spaced server rooms and data processing centers
There`re two categories of application of air-conditioning systems: comfort application for a man, process application for machines. The diagram below shows clearly three areas which would determine composition of the units and necessity of additional freon systems.
- Area 1 – range of climatic parameters where use of UCU without a freon system isappropriate for human comfort.
- Area 2 – range of climatic parameters where use of UCU without a freon system isappropriate for processing procedures.
- Area 3 – range of climatic parameters where UCU should be used with a freon system.
Depending on the application and climatic parameters, it`s possible to determine the composition of the unit.
* The diagram very roughly shows the application areas, we recommend that for each borderlinecase a comparison should be made between freon technology and indirect-evaporationtechnology.
APPLICATION OPTIONS
Classical air conditioning circuit expects the placement of unified air handling units (central air conditioners) serving the room. At the same time, outer air is processed in the central air conditioner and is supplied prepared into the serviced room. To heat up the supply air, heaters are used, and to cool the supply air, air cooling sections are used; these air cooling sections usually use a freon system as a source of cold (chiller or compressor-condensing unit).
Universal climatic units can be used as analogues of the most common systems: central air-conditioner combined with a chiller or a compressor-condensing unit, central air-conditioner with an irrigation chamber, packaged air-conditioner. Also, the units can be used as room terminals which serve not for replacement but for provision of support and stand-by for freon systems.
For clarity, we give the well-known schemes of freon equipment.
STANDARD SOLUTIONS ON THE BASIS OF FREON AIR COOLING EQUIPMENT
* There are other ways to maintain the climate in the room, but they are all based on the circuits described above.
For the circuits with local cold (heat) sources split systems (air conditioners with separated blocks: the outside block (condensing) is located outdoors, and the indoor block (evaporating) is located inside the room) are used as room terminals. Packaged air conditioners are also belong to split systems due to their layout.
APPLICATION OPTION: SUPPLY-AND-EXHAUST VENTILATION
This operation circuit is similar to the circuit Central air conditioner – Chiller (Compressor-condensing unit). The refrigeration machine is excluded. It is required to include an additional air duct in the system to relieve heat when cooling the air, a process air duct. The air consumption in the process air duct is 30% of the air delivered into the unit. The air flow delivered to the consumer is 70% of the air delivered into the unit. In winter, the process air flow is blocked, and the airflow for the consumer is adjusted in accordance with the specified winter parameters.
* Winter operation circuit is basically the same as for the standard solution.
APPLICATION OPTION: SUPPLY-AND-EXHAUST VENTILATION WITH NATURAL EXHAUST VENTILATION
This circuit is similar to the previous aside except for one provision – no forced exhaust ventilation is used. The circuit is excellent for relatively small rooms and contains a minimum amount of maintainable equipment.
APPLICATION OPTION: AIR RECIRCULATION
If necessary, universal climatic units can also be used to recirculate air. To ensure full operation of the unit, compensation is required by addition of outdoor air to the intake of the unit, since 30% of the supplied air should be exhausted with the process air flow.
APPLICATION OPTION: SUPPORT OF THE EXISTING REFRIGERATION EQUIPMENT
For example the building is equipped with equipment, the building is put into operation, but for some reason, the air conditioner does not reach the rated capacity. Up to 24°C ventilation system fulfills its functions and process parameters are maintained. Over 24°C overheating of the building occurs. The solution to the problem may not be redesign of the ventilation system, not its complication, but only one universal climatic unit before air intake. Thus, the central air conditioner will be supplied with 18-24°C, and the previously installed equipment will send the rest of temperature down.
If replacement of the existing equipment is not possible and not reasonable despite all its disadvantages, first of all despite insufficient cooling capacity, we recommend additional conditioning stage – to install universal climatic unit prior to air intake of the central air conditioner.
* Application of this cooling circuit ensures safety of the objects. In combination with a basically different physical cooling principle, different from the vapor compression refrigeration it`s possible
a)to ensure reduction of general cooling capacity of the equipment being designed (first of all,chillers);
b) to increase common safety parameters of ventilation systems.