Paint Colours Can Cut Energy Costs

28th May 2014

One of my favourite parts of Environmentally Sustainable Design (ESD) is the advising on colour selection and surface finishes.  It’s an interesting field because a little bit of thought can make a significant yet cost-effective contribution to building design – assuming for example that you were going to paint a surface anyway.

We’ve known for a long time that colours can affect our moods including making us feel cooler or warmer  – ancient societies used greens and blues in spaces to create a sense of coolth and reds, yellows and oranges to generate warmth.  

Light intensity can change a sense of proportion of a room with lighter shades making a room feel larger.  A darker shade on a ceiling where that ceiling is very high may help bring a room back into a more appealing proportion but from an ESD point of view it is generally considered that the lighter (more reflective) shades have considerable advantages in reducing the need for artificial lighting.

I’ve also been involved in selling non-toxic paints (Bio Products) for the past twenty years. Interestingly the colour ranges of non-toxic paints are more limited (because the paint colours can be the most toxic component and/or there could be issues in sourcing the raw ingredients) but fortunately the colours available are also the colours are in demand.

Another part of ESD is something we call ‘zoning’ whereby different parts of the building (assuming space is available) can be used (or closed off) during different seasons. Here colour, along with textures, indoor plants, indoor water features, etc, can make a useful contribution to comfort, reduced costs (bills) and reduced pollution.

Incidentally, externally, colour and vegetation are also very important in the temperature moderation of buildings. For most parts of Australia, light coloured external walls and roofs would be the preferred option but don’t overlook the role of vines, trees and other vegetation in moderating the ambient temperature. 

Mercedes Martty reports in Sourceable (27/5/14):

"It is no secret that lighter colours reflect more light and absorb less heat while dark colours absorb both light and heat. As a result, a room with light colour walls will need less artificial lighting than a room with dark coloured walls. ... Light coloured walls are ideal for creating an electricity efficient home. They are less heat absorbent, so they stay cooler during summer months, which cuts down on air conditioning costs. During the winter, meanwhile, they do not take up much of the heat generated inside the room. In addition, painting the ceiling a light colour allows it to reflect light much better. Most paints on the market are labelled with a Light Reflectance Value (LRV) corresponding with their colour. The higher the LRV number, the less the need for artificial light. For example, white reflects 80 per cent of light while black only reflects five per cent. ...

"From a psychological standpoint, colour greatly influences human emotions and behaviour. Recent studies have shown that the colour of a room can affect people’s perception of temperature. The studies showed that people estimated the temperature of a room with cool colours such as blue or green to be between six and 10 degrees Fahrenheit cooler than the real temperature. Warm colours such as orange, yellow and red led people to believe the temperature in the room was six to 10 degrees Fahrenheit warmer than it actually was." 

Read Mercedes' full article at: http://sourceable.net/paint-colours-can-cut-energy-costs/

 

Alhambra, Granada, Spain

Picture: Alhambra, Granada, Spain (October 2013)