mechanical

• Mechanical System are the machines used for building services such as plumbing, elevators, escalators, heating and air-conditioning systems.
• The system provides indoor environmental comfort to the users by maintaining thermal comfort and acceptable indoor air quality.
• It provides ventilation, reduces air infiltration, and maintains pressure relationships between spaces.
• The design, installation, and control systems of these functions are often integrated into one or more systems.
• The mechanization of buildings was first introduced in the early 20th century which brought huge adjustments in the building for the new equipments needed extra floor space and they began to add electrical and HVAC.
• In modern buildings with large heat gains, central heating became a little more than a supplement.
• Heat removal became a serious concern especially in warm areas.
• The roofs of high rise buildings were occupied by cooling towers and often the entire floors were reserved for the containment of blowers, compressors, water chillers, boilers, pumps, and generators.
• Air-sourced and ground-source heat pumps are the most efficient and sustainable options, but their effectiveness depends on the building’s size and use.
• GSHPs function like regular heat pumps, transferring heat from one area to another.
• Ground Source Heat Pumps (GSHPs) offer a sustainable alternative to traditional air-source heat pumps and gas or oil furnaces, providing numerous benefits for both homeowners and the environment.
• Both Horizontal and Vertical Ground Source Heat Pump systems provide a long term return on investment despite the initial high costs and add value to your home in terms of a eco-friendly method of heating.
• Ground Source Heat Pumps comply with relevant laws such as Section 1204 of the California Building Code which requires enclosure of vertical openings, and Section 1214 of the California Building Code which addresses motion picture projection rooms.
• Types of Ground Source Heat Pumps include Horizontal Systems, where loops of pipe are buried in trenches several feet deep across a large area, and Vertical Systems, where loops are drilled deep into the ground through boreholes.
• Ground Source Heat Pumps provide consistent and comfortable temperatures throughout the year, regardless of outdoor conditions.
• Instead of relying on ambient air, GSHPs exchange heat with the ground through a network of buried pipes filled with fluid (usually a water-antifreeze mixture).
• Ground Source Heat Pumps offer high efficiency, being up to 400% more efficient than traditional electric furnaces and 50% more efficient than air-source heat pumps.
• With proper maintenance, Ground Source Heat Pumps can last for 25 years or more, much longer than conventional heating and cooling systems.
• In summer, the process reverses: the warm fluid in GSHPs absorbs heat from the building and releases it into the cooler ground, providing air conditioning.
• Ground Source Heat Pumps are quiet, with no outdoor unit, and require very little maintenance.
• Ground Source Heat Pumps emit little to no greenhouse gases or other pollutants, making them a clean and sustainable energy source.
• In winter, the fluid in GSHPs absorbs heat from the warmer ground and carries it to the indoor heat exchanger, warming the building.
• The key determining factor in choosing between a Horizontal or Vertical Ground Source Heat Pump system is the space available, with a minimum of 700 square meters required for the multiple ground loops in a Horizontal system, and two separate boreholes at a 25cm width, and spaced six meters from each other in a Vertical system.
• Energy efficiency is only one factor to consider when choosing a mechanical system.
• Variable Air Volume (VAV) Systems enable energy-efficient HVAC system distribution by optimizing the amount and temperature of distributed air.
• VAV systems supply air at a variable temperature and airflow rate from an Air Handling Unit (AHU).
• VAV systems use flow control to efficiently condition each building zone while maintaining required minimum flow rates.
• A VAV box is considered pressure dependent when the flow rate passing through the box varies with the inlet pressure in the supply duct.
• A pressure-independent VAV box uses a flow controller to maintain a constant flow rate regardless of variations in system inlet pressure.
• This type of box is more common and allows for more even and comfortable space conditioning.
• Exhaust capacity shall not be less than 0.50 cubic meter nor more than 1.40 cubic meter per minute for each arc lamp plus 5.60 cubic meters for the room itself.
• Walls and partitions enclosing elevators and escalators shall be not less than the fire-resistive construction required under the Types of Construction.
• Vents shall be located in the side of the hoistway, enclosure directly before the floor or floors at the top of the hoistway and shall open directly to the outer air through non-combustible ducts to the outside, or in the wall or roof of the penthouse or overhead machinery space above the roof provided, that the openings have a total area of not less than the minimum required.
• Automatic sprinklers shall be provided around the perimeter of the opening and within 60 centimeters (2 feet) of the draft curtain.
• Exhaust systems serving the projection room may be extended to cover rooms associated therewith such as rewind rooms.
• The motor shall not be mounted in the spray booth or the duct system and belts shall be enclosed where they enter the booth or duct system.
• Such draft curtain shall enclose the perimeter of the unenclosed opening and shall extend from the ceiling downward at least 30 centimeters (12 inches) on all sides.
• Ventilation of these rooms shall not be connected in any way with ventilating or air-conditioning systems serving other portions of the building.
• Exhaust ducts shall be constructed of steel having a thickness not less than the values set by the Secretary.
• Elevator shafts extending through more than two storeys shall be equipped with an approved means of adequate ventilation to and through the main roof of the building: Provided, That in buildings housing Groups G and F Occupancies equipped with automatic fire-extinguishing systems throughout, enclosures shall not be required to escalators: Provided, further, That the top of the escalator opening at each story shall be provided with a draft curtain.