Bachelor of Quantity Surveying (Honours)Building Services I [BLD 60403]

Energy Efficient Ventilation System

Ng Chuan Kai 0323738

Boon Li Ying 0323839

Loh Wen Jun 0323551

Tey Cheng Fern 0323912

Vivian Tay Huey Shuen 0323869

Michelle Tung 0324175

Ventilation

• Process of changing air in an enclosed space• Proportion of air should be withdrawn and replaced by the fresh air • Maintain temperature and humidity at comfortable levels and to allow the

indoor air pollution to flow out• Excessive humidity can cause diseases and other symptoms such as

headache, sore throat or even breathing difficulty

Energy Efficient• Energy efficiency means using less energy to provide the same level of energy• Energy efficient is not energy conservation• Energy conservation is reducing or going without a service to save energy

• For example, turning off a light is energy conservation. Replacing an incandescent lamp with a compact fluorescent lamp is energy efficiency.

Ventilation

Natural Ventilation Mechanical Ventilation

Natural Ventilation

Best Selection of the Window

Louvre Window

Louvre Window

Casement Window

Double Hung Window

Sliding Window

Awning Window

Fixed Window

0% 20%

40%

60%

80%

100%

The result of the experiment carried out by Breezeway

Percentage of Ventila-tion

Installation Process1. Fixed top sill with the side jamb and repeat the process.

2. Cut the panel and put the PVC anti-dust strip on the end of each panel.

3. Offer the frame with bolts and nuts and tighten it.

4. Try to slide each individual blade that located between the jams into the aluminium holders.

Best Selection of the Door

Fibreglass Door

Taken from https://www.thermatru.com/learn-plan/shopping-tips-tricks/fiberglass-comparison/

Installation Process1. Apply some beads of caulk to the underside of the door sill and need to seal at least 4 times.

2. Place some solid shims behind the hinge jamb and frame and temporarily secure the unit to the frame by using screw or nails to fasten it.

3. Check the weather-stripping to make sure the margins and contact are equal around.

4. Adjust the door threshold to have an even contact between the door sweep and threshold.

5. Caulk again the intersection of the jamb, brick molds, threshold and floor for in-swing and out-swing door.

Mechanical Ventilation

Best Selection of the Fan

Whole House Fan

Installation Process1. Mark the joist that need to be cut by pushing a nail through the wall as these

nails will be easily seen.

2. Using pushed-through nails in the ceiling as guide, cut and place the template on the ceiling and staple in place.

3. Pass the fan through the opening. Center and attach the fan to the platform.

4. Secure 4 sides of the fan frame by nailing wooden blocks to the platform.

5. Flip the fan motor and rebolt it to the struts. Slip the fan belt into position and slide the motor to achieve proper tension. Be careful not to overtighten.

Management System

Management System

• to provide a healthy and comfortable internal environment for the building’s occupants through - the process of changing air which remove the polluted indoor air from a building and replaced by the fresh air from outside

• to maintain air purity such as preservation of oxygen content, removal of carbon dioxide and control of humidity

• management system is necessary to the energy efficient ventilation system

• -maintain the effectiveness of ventilation regardless of wind direction

• -make sure the inlet and outlet openings are not obstructed by nearby objects

• -the window is located in opposing pressure zone to increase the ventilation rate

• provide periodic maintenance for the system to make sure that the system running efficiently and lead to the maximum of system’s lifespan

• to ensure the reliability of the ventilation system and to secure the operation of the ventilation plant

Passive Stack Ventilation (PSV)

• the most effective natural ventilation strategy as it combines with trickle ventilation through window frames

• one option to provide domestic ventilation

• a combination of the air flowing over the roof and the natural buoyancy of warm moist air to lift the moist and stale air from the kitchen and bathroom up ducting to the roof ridge level where it escapes into the atmosphere

• fresh air is drawn into the building through the trickle vents in the windows and doors

Passive Stack Ventilation (PSV) • PSV system are energy efficient - this

system is without the need for any electric fans or control

• the amount of ventilation achieved depends on - the amount of movement of the external air and the external air temperature

• standard PSV systems have a simple inlet grille to the duct, usually fitted into the ceiling

• cleaning the grilles especially the one in the kitchen is essential -to ensure that there are no restrictions to air flow up each stack

• PSV system requires very little maintenance -a periodic check of the roof terminal and of any ducting that is accessible should be enough to maintain the structure of the system

Mechanical Extract Ventilation (MEV)

• a system that extracts air from wet rooms continually

• consists of a central ventilation unit positioned in loft space ducted throughout the building to extract air from the wet rooms

• replacement dry air is drawn into the building via background ventilators

Mechanical Extract Ventilation (MEV)

• providing a gap at the bottom of the internal doors that allow the free passage of air through the building

• can be operated automatically or manual switching

• able to increase the speed of the fan and extraction rate, rather than raising the extraction rate for the whole building

• require regular maintenance to remove dust and grease from the fans, grilles and filters

Advantages and Disadvantages

AdvantagesReduces energy usage• ‘Energy Efficient’ means use less energy for the same service• Examples are natural ventilation and Mechanical ventilation with heat recovery

Natural ventilationMechanical ventilation with heat

recovery

AdvantagesProvide comfortable microclimate• Example: Geothermal ventilation system

• Provides cool air during hot weather

• Provides hot air during cold weather

Advantages

Saves cost in a long run• More expensive, but can save in long term

• Example: Energy recovery ventilation system

• Operate by transferring heat from warm, inside exhaust air to cold, outside supply air

• Reduce the heating and cooling costs

• Electricity bill is reduced

Enhance indoor air quality• Indoor air is continuously withdrawn and replaced by fresh air

• Oxygen level is preserved at 21%

• Bad odour is eliminated

• Humidity is controlled and balanced

• Reduce stress and improve moods

Disadvantages

High cost in short term• Must pay installing fee in advance

• Must engage specialists such as ventilation engineers

• Service and maintenance cost are required as well

• An example is Energy recovery ventilation system

Requires more time to install• More high tech • Requires efficient preparation to install it• More complicated design• Check ventilation rates• Example: Exhaust ventilation system

Case StudyBurj Khalifa

Burj Khalifa

• A megatall skyscraper in Dubai, United Arab Emirates.

• Multi-use tower that includes residential, hotel, commercial offices, entertainment, shopping, and parking facilities.

• It is the world’s tallest structure ever built.• Height :828m • Numbers of floors:162

Natural ventilation system

• Burj Khalifa has occur the phenomenon as reverse stack effect because the flow of air is downward.

• The cooler air is more dense is inside the building and wants to drop downward and flow out of the building to its’ bottom.

• The air move from the top to the bottom through the elevator shaft.

• Each time the elevator door open it will help to produce greater stack effect.

• This help to reduce the temperature for the whole tower without any cost.

Natural ventilation system

• Glass panel also serve as a function to reduce the temperature and reduce the usage of the air conditioning,ventilation and dehumidification function.

• It is a special panel made from two layers which is a thin layer of metal and a thin layer of silver to keep the temperature inside the building cool by reflecting the heat and sunlight.

Mechanical ventilation system

Plate heat exchanger• Used for transfer heat between two fluid to

reduce the air temperature. • Ice-storage cooling system that produces tons of

ice slurry during off-peak hours.• Using the plate heat exchangers, the ice slurry

built up in a tank, store the cooling energy that is later released, through the pipelines to the entire indoor conditioning and tap water systems.

Mechanical ventilation system

Air handling unit• used to re-condition and circulate air as part

of a heating, ventilating and air-conditioning system.

• improve the air quality of the tower by using the air on the higher level which is clean and cooler air and transfer it to the lower floor.

Mechanical ventilation system

Chilled water pump• Is a heat exchange device • The condenser water absorbs heat from the

refrigerant in the condenser barrel of the water chiller, and is then sent through return lines to a cooling tower.

Possible Problem to the System

Sand Storm

• Sky-sourced ventilation not applicable during that time

• Openings and windows cannot be opened, too dusty• Serious respiratory problem endanger our health

• eg: Breathing difficulties

• Heavy dust particles carried on together with wind pressure

Cont’d

• Concentrate air filters blocks the air ways pass through the filters to the surrounding areas.

Condensation

• Debilitating effect on occupiers of dwelling• If condensation occurs over a prolonged period of time,

other signs• eg: damp patches on windows, walls, black-mold growth

• Introduction of energy saving measures • eg: double glazing and cavity wall insulation • No natural escape route for this stale, humid air now trapped

inside building

High usage of mechanical ventilation system• Huge air conditioning system is constructed in building• Supply throughout entire area of building, ensure thermal comfort

achieved. • Large amount of energy to supply sufficient air to surrounding• High percentage of electricity • Coal-burning power plants, air conditioning contributes indirectly

release of greenhouse gases and other pollutants

Proportion of outside air • Dilute and remove indoor contaminants, HVAC systems must bring

in adequate amounts of outdoor air• Higher cost needed cool hot summer air• Building engineers reduce or eliminate the amount of outdoor air• Allows contaminated air accumulate inside, causing pollutant

concentrations increase• Continuous supply of fresh air must be provided

Blockage in the ventilation system

• Properly maintained to provide indoor air quality• Source of contamination become clogged, reduce or eliminate

airflow provides colder air supply to indoor area• Contaminated or dust particles causing air filter exist blockage, thus

reducing supply of air flow to the building

Cont’d

• Failure to properly treat water in cooling towers to prevent growth of organisms

• Introduce organisms into HVAC supply ducts, increase concentration of bacteria affect indoor air quality and cause serious health problems.

• Accumulations of water around system may bring harmful biological growth can distributed throughout the building.

Recommendation for future improvement

Building maintenance activities

• Source of pollutants used• eg: during painting, renovation, and pesticides

• Schedule a time during use of pollutant sources to minimize the impact on indoor air quality

• Increase ventilation rates during periods of increased pollution in building.

Regular maintenance of the ventilation systems

• To avoid affecting thermal comfort of indoor air quality• Air cleaning regularly done ensure sufficient air distributed

to the building.• All air cleaners must be properly sized and maintained to be

effective

• An HVAC system that properly designed, installed, maintained, and operated is essential to providing healthful indoor air

Avoid and control of outside air and pollutants

• To reduce indoor air pollutants, increase the openings and windows in a building

• Ventilate air of indoor allowing outdoor air to flow in building to dilute indoor air and reduce pollutants

• An adequate supply of outdoor air is essential to diluting indoor pollutants

• In general, increasing rate of outdoor air supplied to the building decreases indoor air problems

Control of condensation in a building• Limiting sources of moisture; including reverse

condensation, which moisture evaporates from damp materials.

eg: replacing flueless gas or oil heaters.

• By increasing air temperature of surrounding indoor can reduce percentage of condensation to overall building

Cont’d

• Dehumidification by removing moisture, water vapor or humidity from the air.

• Natural or mechanical ventilation are also the important factor to control the rate of condensation

• Increasing surface temperatures

eg: inclusion of insulation materials around the building or improving glazing