Making buildings energy efficient should be done without compromising on user comfort and well-being. It should merely enhance the quality of living and reduce the cost of living in the long run.
Oftentimes, the productivity of users subconsciously tends to depend on certain design factors like indoor lighting, ventilation, temperature etc. These factors should be studied thoroughly and implemented in our designs to avoid sick building syndrome.
User comfort majorly depends on the following aspects:
Indoor Air Quality (IAQ)
One of the most important aspects that need to be carefully analyzed in our projects is the ratio of daylight to artificial light.
Aspects Of Visual Comfort
1. Importance Given To Daylighting
Daylighting has been scientifically proven to improve the mental health and productivity of the occupants, but only up to a certain point.
Factors Affecting Availability Of Daylight:
Climate: A cloudy or rainy day means less daylight. Artificial lighting should be readily available in such cases.
Radiation: Too much heating that comes with daylighting is not preferred.
Orientation Of Building: No matter how many fenestrations or openings you have, daylight doesn’t actually come in properly unless the building is oriented the right way.
Structure And Shape Of Building: The building’s own structure and shape should not hinder daylight.
Ways To Improve Daylighting:
Building Orientation: Orient the building and give openings in a direction that allows more light but less heat. Usually in India, this orientation is along the North-South direction with the placement of openings on the northern wall.
Material Choice: Materials like triple glass, which reduces transmission of heat while not obstructing light can be used.
Recessed Windows: Shading or recessing windows reduce heat gain by building interiors.
2. Sustainable Artificial Lighting
Although daylight is extremely important, it is not a constant source of lighting that we can depend upon.
Factors Affecting Sustainable Artificial Lighting
Power Consumption: In recent years, technology has improved leaps and bounds in the field of lighting too. Less energy is consumed for a higher output than compared to what it was ten years ago.
Heat Emitted: A decade ago, energy in the form of heat would be dissipated from lighting fixtures, making interiors uncomfortable. LED lights and other similar technology reduce energy waste by reducing the emission of heat.
Ways To Improve Artificial Lighting:
Efficiency: Look for green-rated and efficient options while choosing.
Choice: The placement and type of lights should be predetermined keeping in mind the comfort and ease of use of the users. For example, target lights placed near the bed are ideal for people who have a habit of reading before going to sleep.
Desired Lighting Options: Lighting fixtures today come in all shapes, sizes and colors. They can even be custom-made to suit our designs.
3. Reduce Glare
The ideal amount of lighting required for an average human is around 300 lux. Going more than this increases discomfort and glare happens when the value reaches around 1000 lux.
Factors Affecting Glare:
Amount of lux: Keep the light output to around 300 lux for comfortable lighting.
Path and direction of light: The lights shouldn’t directly face the user themself as it might harm their eyes.
Ways To Reduce Glare:
Regulate The Amount Of Light: Keep the output ideal for the situation. Restaurants may need lesser lighting than a school; Hospitals may require more daylighting than office spaces.
Reduce Light Reflecting Surfaces: Glare also happens when the path of light is reflected from highly reflective surfaces.
4. Choice Of Color And Color Index
Comfort also depends on the choice of color of the lighting of that particular space.
Factors Affecting Choice Of Color:
Requirements: The color of lighting fixtures depends upon the type of space. A clothing shop usually has warm yellowish lighting which brings out the colors of the clothes on display while railway stations have bright white lights.
Preference Of The User: In most private spaces like homes, the color of lighting usually depends upon the choice of the occupants.
While some spaces need acoustic privacy, others need sound to reverberate clearly enough to reach the ears of every user.
Aspects Of Acoustic Comfort
Sound-proofing is done when privacy is needed. This is a crucial aspect while designing homes, schools, hospitals etc.
Factors Affecting Sound-proofing:
Placement Of Spaces: Placing activity spaces to one side and private ones on the other helps reduce privacy invasion due to noise.
Material Choices:Acoustic walls and partitions stops noise from one room from going to the next.
2. Acoustic Quality
Classrooms, theaters, Concert halls etc. require good sound propagation to ensure clear and good quality hearing.
Factors Affecting Acoustic Quality:
Reverberation Time: The time required in a space for the sound to fade away.
Shape Of The Space: The shape and orientation of a room plays a huge part in sound propagation. Longer and fan shaped rooms have the best sound quality.
Ways To Improve Acoustic Quality:
Fan-shaped rooms: Fan-shaped rooms with the speaker standing in the center is ideal for good acoustic spaces.
Material Choice: Acoustic panels and foams can be used to control reverberations, and hence, the quality of sound.
Indoor Air Quality/ Ventilation
Providing proper ventilation increases productivity time of users.This should be a mix of natural and forced ventilation.
Aspects Of Ventilation
1. Flow Of Air
Fresh airflow is crucial for both physical and mental health.
Ways To Improve Flow Of Air:
Openings: Windows, ventilators and other ventilation devices should be provided.
Cross Ventilation: Windows and other openings should be placed on the opposite side of rooms to increase chance of cross ventilation.
2. Removal Of Stagnant Air Inside Air Conditioned Spaces
Since an air conditioner consumes more power cooling hot air than the already cooled air, the same air inside the room is allowed to circulate in the name of saving energy. This not only reduces comfort and productivity, but also is harmful for the user’s health.
Ways To Remove Stagnant Air From Air conditioned Spaces:
Flow Of Air: Opening windows and other structures should be opened every hour or so to let fresh air in to be cooled again by the air conditioner.
Thermal comfort refers to the ideal comfort temperature for a person. It is subjective and has no specific value or conditions.
Aspects Of Thermal Comfort
1. Regulating Temperature
The indoor temperature should be comfortable for the occupants.
Factors Affecting Regulating Temperature
Climate: Difference in interior and exterior temperatures.
Artificial Devices: Availability of artificial cooling or heating devices.
Ways To Regulate Temperature
Passive Methods: Using passive cooling/heating techniques depending on the climate of the place.
Active Methods: Employing cooling/heating devices to artificially regulate the interior space.
2. Considering All Groups Of People
Ideal comfort temperatures vary from person to person. Generally, women prefer warmer conditions compared to men. This factor also depends on age, origin, culture etc.