Cool Tool AC

THRMAL COMFORT IS A CRITICAL factor in workspace, which have to be designed to provide a certain degree of comfort. And offices, large and small, are being modified to account for this. This section covers common methods of air-conditioning used in workspaces.

BASICS:

• HVAC: A system that provides heating, ventilation and air-conditioning through individual or combined processes.
• Air handling unit (AHU): This component of a HVAC system conditions and circulates air. It is usually a room equipped with supply-return fans that maintain air movement, heating/cooling coils that control the moisture content of the air, and filters that condition the air.
• Conditioned space: Any space within the building, where thermal comfort is provided.
• Ducts: A duct is an encased channel, through which air moves around in a HVAC system. It can be made of metal (usually aluminum), fiberglass or other flexible material.
• Air inlets: grills, louvers and diffusers through which air is drawn out from a conditioned space.
• Air outlets: grills, louvers and diffusers through which air is delivered into a conditioned space.
• Conditioned air: Air treated in an AHU to alter humidity, temperature and cleanliness levels.
• Exhaust air: Air discharged outside, from any space within the building.

METHODS:

Most workspaces use two methods of air conditioning:

• Central
• Portable

CENTRAL AIR- CONDITIONING:

Central air- conditioning in workspace is usually done through the ceiling. Ducts distribute cool air to multiple rooms.

Advantages-

• A single system can be used to air-condition huge spaces.
• A central air-conditioning system is more efficient than individual AC units.
• All cabling and wiring is done through ceiling ducts, so no messy cables and wires are visible.
• Sophisticated filter system are capable of removing microscopic particles. Air from outside is continuously pulled in through a filter, where air borne particles are removed.
• Since the whole system is controlled in the AHU, the noise level in the workspace is cut down.

Disadvantages-

• The thermal Level can be controlled only in the AHU, so the entire system runs at the same temperature.
• The whole system shuts down in the event of a failure.
• The entire system has to be kept running, even if a part of the workspace is not in use.

PORTABLE AIR-CONDITIONING UNITS:

• Portable AC units or individual AC units are an alternate method of air-conditioning. These units can be easily transported on wheels or fixed in the office. Individual units come in two forms: split ACs and monoblock ACs.
• Monoblock units have ducts that vent return-air to the outside of the building. The units are fixed in the windows of external walls. The air is then replaced by fresh air form outside.

Split AC units filter the return-air into fresh air that is circulated in the room. They can be fixed on internal as well as external walls.

Advantages-

• Individual units can be used to cool office spaces which are not used often such as auditoriums, meeting rooms, hub rooms, server rooms, recreation rooms, resting rooms, etc. This proves more economical, as unlike a central air-conditioning system, all the units are operate separately.
• Since each unit is an individual entity, the thermal level in each unit can be controlled.
• The central air-conditioning system can be turned off when not needed. This saves power.

Disadvantages-

• The space does not look very neat, since the units project out of the walls.
• Wires and cables are visible.
• The noise level cannot be controlled.

COOL TIPS:

• Select your air- conditioning system based on the type, usage and the hours of occupancy of the space, as well as the number of occupants and the type of equipment in the space.
• Solar load is directly proportionate to the orientation of the building and the glass areas. A north- south orientation has less solar load than an east-west orientation. Hence, it is preferable to use glass on the north-south faces of the building. Also, using smaller sized window can reduce the solar load.
• Glare-reducing glass or tinted glass can be used on the external feces of the buildings.
• Lighting fixtures should be carefully selected, since they emit heat.
• Excessive usage of wood should be avoided, since wood emits heat.
• Natural stone (marble and granite), metals (steel and aluminum) and gypsum board absorb heat and keep the room cool.
• Odour absorbers and air freshers are a must, to avoid stale smelling rooms.
• And lastly, make alternate provisions for fresh air. This can include balconies, terraces and recreation zones.