House Design

Eco cooling – sustainable air conditioning for your home

Discover eco cooling options – the greenest ways to keep your home from over-heating

Eco cooling - living room with fan and air conditioning
(Image credit: Ryan Christodoulo/Unsplash)

Looking for eco cooling solutions? Keeping your home at the right temperature can be an energy-intensive process, and not as eco friendly as you’d like it to be, nor as kind on your pocket.

Air conditioners are a popular way to cool your home, and there are modern versions that can keep interiors at a pleasant temperature with less energy use. But there are plenty of other possibilities, too, that could help you go greener without sacrificing comfort.

See: Eco home improvements: how to make your house greener

Bear in mind that there are measures you should take to keep the heat out of your home before you decide on the most eco-friendly cooling option. ‘Typically, sealing and insulating attics, basement walls and floors (ie, above unheated spaces, such as a garage or crawl space), and around exterior windows, doors and walls are the most critical points,’ says Steve Dunn, Technology Manager for Home Performance with Energy Star. ‘Homeowners can also reducing cooling load through use of exterior shading and window attachments, such as shades, blinds, solar screens and applied solar films.’

Take a look at the eco cooling options available in our guide.

April 2021 is our Green Homes month. Throughout this month and beyond, we will be highlighting the changes you can make to your home to make them more sustainable – from big projects, such as heating and cooling, to small changes, like buying sustainable homewares.

Find more eco guides on our dedicated page.

1. Improve the eco credentials of your air conditioner

Eco cooling - living room with fan and air conditioning

(Image credit: Ryan Christodoulo/Unsplash)

Some three quarters of all homes in the US have air conditioners, according to Energy Saver, the office of the US Department of Energy that provides energy efficiency and renewable energy information to consumers. In turn, these units are costing homeowners a total of about $29 billion annually, the office says.

‘While there is no specific age for when a system should be replaced, the typical lifespan of residential air conditioning systems is between 15 and 20 years; systems in extreme climates, however, may have lifespans closer to 10 years,’ says Steve Dunn. Swapping from an older air conditioner to a modern high efficiency unit with the Energy Star label can reduce energy use and save money. The endorsement shows products meet strict energy efficiency guidelines set by the US Environmental Protection Agency.

Bear in mind that a central air conditioner requires a blower motor and that’s generally part of a furnace. For the air conditioner to attain its rated efficiency it should not be connected to an older furnace – especially one over 15 years old – and blower motor. In other words, for a greener home, replace the heating system, too.

Room air conditioners, meanwhile, should always be properly sized to avoid wasting energy. You can work out which room air conditioner is needed with the Energy Star step by step guide. 

Regular maintenance of an air conditioner is essential to keep it functioning efficiently. The filter should be cleaned or replaced routinely to keep energy consumption down. The evaporator coil should also be checked every year, and cleaned as necessary. Drain channels will benefit from a having a stiff wire passed through them to prevent them clogging up. And if the fins on evaporator and condenser coils become bent, get a fin comb to restore them. 

Live in a humid climate? ‘Efficiently providing cooling in humid climates involves much of the same strategies as other regions, but with emphasis on humidity and moisture control in the home,’ says Steve Dunn.

‘In very humid climates, the air conditioner alone may not be able to remove enough latent heat to keep relative humidity below 60 per cent,’ he explains. ‘In such cases, supplemental dehumidification and humidity controls can be added to the HVAC system.’

2. Boost ventilation 

Eco cooling - living room with ceiling fan

(Image credit: David Hunter/Unsplash)

Natural ventilation could be enough to keep your home cool, depending on the climate – although other solutions may need to be added (see below) – and is an eco friendly solution. Ventilate the house at night by opening windows to let fresh air in and warm air out. Natural ventilation should always be combined with strategies that keep heat out of the house such as insulation, landscaping that creates shade for the house, and keeping doors and windows closed and pulling down shades on hot days. 

You can add in options such as ceiling and window fans plus freestanding fans as necessary. These use relatively little electricity, according to Energy Saver. A ceiling fan is the best option for making a room feel cool, and can also be combined with air conditioning as it will allow you to raise the thermostat, saving energy.

You might need a whole house fan if your home is large, and one of these can be used instead of an air conditioner for a large part of the year in most climates. It might need to be combined with ceiling and other fans for optimum comfort, however. 

A whole house fan works by bringing in air through open windows and has an exhaust through the attic and roof. Professional installation is recommended. Be cautious, too. ‘Open windows throughout the house to prevent a powerful and concentrated suction in one location. If enough ventilation isn’t provided, the fans can cause a backdraft in your furnace, water heater or gas-fired dryer, pulling combustion products such as carbon monoxide into your living space,’ warns Energy Saver.

3. Opt for an evaporative cooler

living room - eco cooling

(Image credit: OKA)

If you live somewhere with low humidity, an evaporative – or swamp – cooler can be an effective and energy efficient choice, and therefore a more eco friendly way to keep the temperature in your home comfortable. In fact, one of these uses around a quarter of the energy of a central air conditioner, according to Energy Saver.

An evaporative cooler passes hot outdoor air over water-saturated pads so its temperature drops. A fan blows this cool air into the house, and warmer air is pushed out through the windows, which need to be partially open. Instead of blowing the air into a central part of the house, it could be connected to ductwork to channel the air to individual rooms. The latter system is essential for a large house, although the former could suit a smaller home with an open layout. 

Bear in mind that evaporative coolers require regular maintenance that exceeds that of air conditioners. They also use water, which might be an issue where you live.

4. Use a heat pump

Ground source heat pump - eco cooling

(Image credit: Vaillant)

If you’re considering switching to a heat pump as an eco heating option, you’ll be glad to know that it can also provide energy efficient cooling for your house. Both air source and geothermal heat pumps can cool as well as heat a home.

‘Ground source heat pumps are more energy efficient than traditional central AC systems,’ says Steve Dunn. ‘They can operate in any climate, because of the earth’s constant temperature underground (ranging from 45º to 75º F depending on location). GHPs can cut energy bills by up to 65 per cent compared to traditional HVAC units.’

When you’re selecting a heat pump, look at the Energy Guide label, which will show you the cooling efficiency, given as a seasonal energy efficiency ratio (SEER). This is the total heat removed in the annual cooling season in British thermal units (Btu) divided by the total electrical energy consumed by the heat pump during the same season in watt-hours. 

See: The world's most beautiful eco houses – from forest dwellings to city homes

As with other eco home choices, look for an Energy Star label to identify the most eco friendly choices whether you’re opting for an air source or a geothermal heat pump.

Sarah Warwick

Sarah is a freelance journalist and editor writing for websites, national newspapers, and magazines. She’s spent most of her journalistic career specialising in homes – long enough to see fridges become smart,
decorating fashions embrace both minimalism and maximalism, and interiors that blur the indoor/outdoor link become a must-have. She loves testing the latest home appliances, revealing the trends in
furnishings and fittings for every room, and investigating the benefits, costs and practicalities of home improvement. It's no big surprise that she likes to put what she writes about into practice, and is a serial house revamper. For Realhomes.com, Sarah reviews coffee machines and vacuum cleaners, taking them through their paces at home to give us an honest, real life review and comparison of every model.