A room airconditioner is ideal for rooms upto 200 sq.ft when one of the walls is exposed to the outside.
If there are no exposed walls a Split AC is the only option. In addition, in a Split AC the compressor is kept outside and hence, noise levels are lower.
Window ACs and Mini Split ACs work on single phase. However, it is better to have a 3 phase supply and distribute the other loads like Geysers, washing machines, pumps and lights in the other 2 phases.
The compressor which is the most critical component in the AC works between 190 to 240 V. With voltages in most parts of our Country going well below 190 V, we recommend using a Voltage Stabilizer.
Filter cleaning depends on the frequency of usage and the atmospheric conditions. For normal applications, it is recommended to clean the filter once in 15 days.
Rotary Compressor compresses the refrigerant gas by a rotating mechanism while a Reciprocating Compressor does the same by converting a rotating action of a motor into a liner action.
For areas more than 500 sq.ft, it is better to cool the air at one point and supply it through ducts to ensure that the distribution of air is uniform at all points. In common parlance this is called "Central AC".
Ducted Splits are ideal if floor space is at a premium (or just not available). They are mostly used for areas of 2000 to 3000 sq.ft.
Packaged ACs are more rugged than Ducted Splits and are used where small areas can be spared for locating units. They are more common for areas upto 10000 sq.ft.
Water Cooled units are the best choice. They consume less power and have a longer life. However, you will need 15 litres of water per hour per ton of Airconditioning. If this quantity is available then Water Cooled units are the obvious choice. Otherwise, choose Air Cooled units.
No. Central plants with Packaged / Split units cost around 25 K per Ton. With larger customized plants, the prices are higher at around 35 to 40 K per Ton.
3 phase units are better especially when multiple units are used as they ensure better balance on the power system. However, they can be used only if all 3 phases have power, whereas Single phase units can be used even if power is available in any 1 phase.
While conventional large Central Plants have been used in theatres to take care of the large fresh air load, floor mounted packaged units have become a good option. These units' efficiency in handling fresh air, their multiple steps of control combined with their low cost, have made them the best choice for theatres.
Not necessarily. While false ceiling does reduce the cooling load when non ducted units are used, it is provided mostly for aesthetic purposes. If you have no problems with exposed ducts, you don't have to provide false ceiling. Alternatively, flexible ducts with better finishes and Turbo Splits are also available.
. Specify energy efficient systems like Scrolls, Centrifugals.
. Ask for details of part load performance. AC Systems are designed for peak loads which occur only for 2% or so of the time. How the AC works during part loads is important.
. Use multiple circuits wherever possible for better part load performance.
We would strongly recommend that you do. Insulating the Underdeck of an exposed roof with 50 mm Thermocole saves nearly 2 Tons of airconditioning. The cooling load with insulation is around 6 Tons. Without the insulation, it would be 8 Tons or 33% more. Not only do you have to pay more initially for larger equipment you will unnecessarily spend money continuously on power.
. Initial cost is a primary concern
. A large project is done in phases and funds flow will be in phases
. When different companies/ independent divisions are buying separate wings / floors in a large multistoreyed building.
. Jobs have to be completed in 2 to 3 weeks.
. When a full fledged maintenance team is not available at site.
. Working hours are staggered in different wings/ floors.
Central Plants can be used when
. A large project has to be completed in one shot.
. When higher initial costs are acceptable but operating costs have to be lower.
. Working hours in a large complex are more or less the same.
The feeling of coolness or warmth is highly individualistic and depends on each person's metabolism. It is however imperative that temperatures are maintained uniformly at each nook and corner of the Office. Balancing the airflow is very important to achieve uniform temperature.
Where AC is used for human comfort, the ideal setting is 24oC. AC experts have determined that the comfort zone is between 20 to 25oC with RH between 40% and 60%.
Keeping the door open obviously means that cold air will get out leading to loss of efficiency in the AC system. However, in establishments where there is no choice but to keep it open "Air Curtains" can be installed. These curtains provide a sheet of air at the opening which prevents cold air from getting out.
It is true that improperly designed ducting/ boxing results in sound carry over. However, by designing ducting/ return air collection properly, this can be avoided.
Bad smell inside an area prolongs for a long period as the AC system keeps cycling the same air. For areas like Restaurants/Bars, which can handle ACs fresh air like Packaged Units/ Ducted Splits should be used. Keep the fresh air damper in the correct position to ensure flow of fresh air.
Smoke being heavier than air tends to stay within the airconditioned areas. The absence of fresh air to dilute smoke levels could also result in this. Hence, use Packaged Units/ Splits which can handle fresh air and also ensure higher velocity of supply air in the room to remove the haze
It is important that the patient in an Operation theatre does not get infected. Using Windows/ Splits means recirculating the same air over and over again and it is quite possible that a patient in the theatre picks up an infection from a patient who has had an operation before him.
Hence, depending on the critical nature of operations- Packaged Units or custom designed Central plants should be used.
Bacteria is normally of 1 micron. To ensure that bacteria is filtered, it is necessary to have special filters which can filter upto 0.3 microns. It is also important to circulate the air many times through this filter so that the bacteria gets filtered. Hence, a very high volume of air has to be circulated.
A Software office is normally heavily populated. Moreover, carpets, printers, xerox machines and other office equipment need a larger quantity of fresh air than normal. It is recommended to use at least 15 cfm of fresh air per person.
