Water Heating and Conservation

Second only to the cost of heating and cooling a home, water heating is the next large portion of a typical household utility bill. Water heating is usually responsible for around 18% of a home's utility costs each month. By using more efficient methods of heating and limiting water usage in your household, you can lower your home's carbon footprint, save money and help to conserve one of the world's most precious resources.

Water Heaters

There are many different types of water heaters available on the market. The most popular type is the traditional system with a large tank for storing a supply of hot water. This kind of water heater is low in cost and delivers hot water to the shower head or faucet when the hot water tap is turned.

  • Conventional water heaters may use natural gas, propane, fuel or electricity to heat the water and keep it hot until you need it. The conventional water heaters are always using energy in order to maintain a supply of water at the temperature setting on the tank's thermostat. The loss of heat through the tank is referred to as standby heat loss and can be a considerable drain on your wallet. A stored water heating system also has a limited supply of hot and ready-to-use water. The tanks come in capacities of 150 to 300 litres. Once the hot water is used up, it will take a while for the tank to replenish the supply.
  • Tankless or on-demand water heating systems do not have a storage tank, which means there is no standby heat loss. Instead, their heating elements are directly activated by the flow of water. Fuel is only used when hot water is needed. This type of a water heater uses 8% to 34% less energy than a conventional water heater. However, the cost of installing an on-demand water heater is high and the process of installation may be lengthy. Tankless water heaters also have a limited flow rate, which could result in low water pressure when you take a shower. If you try to use a hot water faucet and the hot shower simultaneously, the on-demand heater may not be able to supply the hot water that you require.
  • Heat pump water heaters use electricity to move heat rather than producing it. These systems are two to three times more efficient than traditional water heaters with a tank. The heat pump systems draw in heat from the air and therefore must be located in a space that has excess heat. The pumps actually cool the space around them. This means that owning this type of water heater could increase the demand on your furnace or boiler during winter. A heat pump water heater can work on its own or it can be integrated into your home's air source heat pump for home heating and air conditioning.
  • Solar powered water heaters are a great choice for many residential buildings. These systems are up to 50% more energy efficient than a gas-powered or electrical water heater. The setup harnesses the sun's heat in order to provide hot water. Solar water heaters can be large in size and include storage tanks, solar cells or collectors and pipes. They can be used to heat the water directly or indirectly through the heat transfer of fluid in the collector.
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  • Flat box solar collectors use an insulated box for transferring heat. With an integral collector-storage system, water is passed through several black storage tanks in an insulated box. An evacuated-tube collector removes the air from the heating system so that there is no conductive or convective heat loss. These systems are usually set up with a backup water heating system powered by electricity or natural gas. The backup systems are used when there is not enough solar energy available to heat the water and also when the demand exceeds the system's capacity. If your home uses a space heating system, a tankless coil or indirect water heater can be combined with it. Your plumber can set up a heating coil or a heat exchanger that will provide hot water on demand. These systems are most efficient in the wintertime when your home's heating system would be in use.
  • The indirect water heating systems need to have a storage tank for the hot water. They can be powered with solar energy, electricity, natural gas, oil or propane or a combination, such as solar power backed up with electricity.

Consider your location and climate before deciding between tankless systems and systems that use a storage tank. A tankless water heating system is typically powered by gas or electricity. Such systems have a low maintenance cost when compared with a system that uses a storage tank. This is because the storage tanks have a tendency to develop rust and mineral build-up through hard water. On the other hand, the tankless systems may not be cost-effective for houses that are located in warmer climates.

Water Heating Tips

You can use the following water heating tips to lower the cost and energy usage for your home's hot water needs.

1. Install a water heater that is more energy efficient.

Inspect the energy label from the manufacturer. It will explain the annual energy usage and operating cost for the system. You can also look for a model that is Energy Star rated. These systems use about 30% less power than other similar models without the rating. Consider converting to solar systems and only using electricity or gas as a backup heating method.

2. Consider replacing your home's boiler.

Keep in mind the fuel type, as gas powered boilers are more energy efficient than electrically powered ones. If you have a family, a regular boiler will be more efficient than a combi boiler. Consider the amount of space you have and whether the system is compatible with the existing solar heating.

3. Have your plumber install a drain-water heat recovery system.

These systems are able to recover the heat of your waste water from showering, washing dishes and using the clothes washer in order to apply it to heat new, clean water.

4. Keep your water heating equipment properly maintained.

Follow the owner's manual guidance on draining water heater storage tanks in order to remove sediment. Check the heater regularly for rust stains and slow leaks. Have gas-powered systems professionally serviced and checked for proper flue operation.

5. Upgrade to energy efficient clothes washers and dishwashers.

These systems use fewer litres of water per cycle and do not generate as much excess heat when heating the water. The newer appliances are designed to only use as much heat as needed.

6. Insulate your water storage tank.

You can purchase an insulation blanket and wrap it around the storage tank of the water heater. Sleeves are available for wrapping around hot water pipes to reduce heat loss through the metal.

7. Use less hot water.

Wash shirts and trousers in cold water. Take shorter showers and avoid taking baths. Use cold water for rinsing your dishes.

8. Turn down the thermostat on your water heater.

Older units will have a dial while newer systems may have a digital thermostat. Set it to no hotter than 50 degrees Celsius.

Water Saving Tips

  • Fix leaks. Learn how to use a plumber's wrench to tighten fixtures. Check the toilet flanges and replace rubber that is cracked.
  • Install low-flow fixtures. These aerate the water so that less water flows through but the pressure is the same. You can unscrew the old showerhead and screw on a low-flow unit.
  • Bathe less. A bath uses around 75 to 100 litres of water, but you could use less than half of that for a shower.
  • Place a water displacement device in the toilet tank. This device stops the tank from refilling all the way when you flush. If you do not own the device, simply place a bottle of water in the tank.
  • Track your daily water use on your water meter.
  • Do not waste water. Shut off the water when lathering your face, shaving and brushing your teeth.
  • Wait until you have a full load of dishes or clothes to do the wash.
  • Use greywater to water your lawn.
  • Properly maintain your lawn sprinklers.

Home Irrigation Systems

Almost half of drinking water is used to irrigate lawns and gardens. Most homeowners overwater their lawns. Consider replacing an old, automated irrigation setup with an above-ground, non-automated irrigation system. The above-ground systems use half as much water.

Make sure that your irrigation equipment has a functional rain or moisture sensor that controls the system. This smart device ensures that your lawn is only watered when needed using the correct amount of water. Irrigation systems should shut off during and after rain storms.

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You can also save water by making some changes to your landscaping. Choose drought-tolerant grasses that grow deeper roots and do not die off during dry conditions.

Improving your home irrigation system, in addition to conserving water and selecting energy efficient water heating systems, can significantly lower your utility bills. These techniques also help reduce the use of fuels and natural resources, the most important of which is water.