【 Weak current College 】 fan coil selection, verification and analysis of the case--layout-Power By 【 China power house network 】

With top-grade office building, Office environment continues to improve, the air conditioning system is increasingly widely deep into daily life. How to enable the use of air conditioning system to best effect, in addition to the design of rationality, are increasingly thinking causing field engineer.
Air blower plate Tube as a central air conditioning system of the terminal units, of the many public places, widely adopted, its main characteristics are as follows:

First, since a unit, adjustable. Air blower plate Tube to third gear variable speed, and waterway system can be set at room temperature, hot and cold water temperature regulating valve adjustment of automatic control, so that the room temperature can be adjusted independently to meet the needs of different air conditioning use on customer requirements, the room nobody used manually shutdown or automatically scheduled shutdown, and allows developers to avoid too great a time investment to facilitate the progressive development, in accordance with the conditions of admission to the customer opened a different room. Reducing the overall cost of running the system.

The entire system partition control more easily, you can press room towards, the floor, purpose, use time, divided into several regions, according to the needs of different customers use partitioned control, thereby avoiding the windy road system must be centralized control of irrational side.

Second, fan-coil block small, flexible arrangement, easy installation and take up less space, ease of construction with built-in. But according to the different needs of the owners, combined with design drawings select better fan coil applied to practical engineering, should take full account of the following:

1. checking of chilling

General is the cooling load calculation according to select a product, but it should be noted that different fresh air supply mode will result in the fan coil is also different load cooling capacity. When the outdoor air directly through the wall to the room without thermal treatment, fan coil cooling capacity = room cooling load + fresh air cooling load; after the establishment of an independent air supply system, the fan coil cooling capacity = Interior cooling load. Currently on the market of the product, usually nominal cooling capacity and actual operation of cooling capacity should be cold × unit of time of an average running time, that is, change the run-time or air flow will affect the amount of input-cooling unit. Therefore not nominal cooling capacity higher the better, if only by high cooling capacity selection units, cooling capacity is too large to cause the start rate too low, ACH, room temperature gradient increase, but also to increase system capacity and equipment investment, energy consumption, reducing air conditioning effect. So cold only as one of the necessary conditions for the selected device, you should also take into account factors.

2. air flow calibration

Main press room quality check of ACH. The smaller the air temperature, ventilation, the more the better air quality, the more comfortable, and why some air conditioning room feel smell, suffocated, is air check not handled properly. Because of the fan coil is in access to water and air, air import and export pressure differential zero condition determination, so there are some practical considerations, so the actual amount of wind is determined should be part of the ideal state of the air flow value deduction calculation, through experience, this part in addition to the nominal air flow rate should account for 20-30%.

3. delivery, return air ways

How to send and return air that form the so-called air distribution, it is reasonable or not directly affects the air conditioning room temperature and velocity field uniformity and stability, i.e., the air conditioning effect is good or bad. Reasonable airflow requirements certain air flow speed,to avoid short circuit, to ensure that certain Jet length. Wind speed depends on the machine, pressure, air, air, and other factors. Machine external static pressure too low can cause air volume decrease, with a range of hot and cold reduction, rooms, air distribution and actual design operating state in the graphs on the larger difference should be based on the actual pattern of building, room structure, depth, height, choose medium wind, wind speed indicators to the appropriate selection of fan coil model. The current market air blower plate Tube, all manufacturers of machine there is no uniform external static pressure value calibration, larger differences, plus the portion of the site is horizontal dark machine group, add a short wind pipes, filters, import and back style gate resistance value is large, so the actual time of order to determine the value of the selected external static pressure, for 30Pa room or even select 50Pa outside the machine, the static value is greater than the conventional units of 20Pa, around resistance value in practical operation guarantees a good uniform field to achieve the desired effect of empty faded by.

4. other factors

A £ ® noise index control in 40dB following, noise is big fan coil units, retrofit muffler treatment unit, the resistance value is not greater than 10Pa.

B £ ® installation, construction insulation quality in the quality of attention, condensation water discharges, slope, pipe joints, and system clean.

C £ ® water system is set up level system or vertical system, some sites use vertical system can better guarantee the condensate discharge, guarantee the room's floor high requirements.

In short, in the design and construction personnel reasonable and timely, fan-coil system would avoid more drawbacks of selection, obtain a more satisfactory overall effect.