- 1 Hot Water Heater
- 1.0.1 Costs Of Hot Water
- 1.0.2 Electric or gas, solar or heat pump … Decisions decisions
- 1.0.3 Electric Hot Water Heater
- 1.0.4 Gas Hot Water Heater
- 1.0.5 Solar Hot Water System
- 1.0.6 Heat Pump Water Heater
- 1.0.7 Storage tank or instantaneous heater?
- 1.0.8 Household size and water usage
- 1.0.9 Energy star ratings
Hot Water Heater
When a hot water heater decides to goes it tends to go all of a sudden. When that happens you don’t really have the luxury to pick and choose what available options you have. Instead you get the same type and style replaced unless you like cold showers ASAP. Once the new one is in and running like a charm then comes along the catalog with all the sales and try to forget about it until next time. There can be and maybe a better product out there for you but if you don’t know then it’s hard to choose.
Costs Of Hot Water
Water heating accounts for a quarter of typical household energy use. It could be worth reviewing your hot water system usage well before your current hot water systems dies and then checking out the alternatives. You might find a hot water system (HWS) that saves energy and money and is kinder to the environment and kinder the the wallet
With new housing and current regulations the aim of reducing energy consumption now means a new electric storage system is not an option for any new homes. If replacing old electric HWS like for like then that is ok. It will come to a point in time many years don the track tho that electric hot water services will be phased out.
Electric or gas, solar or heat pump … Decisions decisions
The first decision you’ll need to make when choosing the best hot water system for you is it going to be gas, electric, solar or heat pump?
Electric Hot Water Heater
An electric hot water heater tank system is usually cheap to buy and easy to install if replacing old for new. There simple design makes them perfect for that reason but in saying that they can be very hungry on power and costs. Some areas offer both on peak and off peak power to which if you have off peak this helps a lot with costing wise. As you guessed there more expensive to run especially if it’s on continuous electric power.
One down side about electric storage hot water systems is for the average house it has a larger storage tank. All the water in the tank will be heated and all that water is heated overnight and has to last you all day unless you go to on peak then the price of power sky rockets to heat it. Off-peak electricity isn’t available to all homes so just check before changing systems. On average a four-person household typically needs a 125 ltr–160 ltr tank for a continuous system which is power to it all the time like having an electric urn on all the time or 250 ltr–315 ltr for off-peak. The beauty about these systems is that can be installed indoors or outdoors. There is also instantaneous electric hot water systems that are normally mounted under a sink for the likes of a office with huge demand for coffee
Cost: They range in price from around the $300 mark to around $1500 and that’s not including installation costs. A standard electric swap and go normally takes about 2 hours from start to finish as a guide depending on location travel etc etc.
Gas Hot Water Heater
Gas hot water systems come in couple different styles. Like the electric you can get gas hot water tank or instantaneous gas hot water system.
Cheaper to run then a electric storage tank is the gas but same thing tho as heating the complete tank once the temperature gets to a certain point and fires up the unit. These tanks always have a pilot light running even tho its a small flame it’s using gas 24/7 You can buy both these heaters in natural or lpg gas. Natural gas is a good option if you have the connection for it. It’s cheaper than electricity (though gas prices are rising) and because gas rates don’t vary through the day gas hot water systems can heat water as needed without huge price varies like electric does with off and on peak rates. There is a lot more regulations on where and how to install gas hot water services as like electric tanks.
A standard four-person household should have a tank size of about 135 ltr–170 ltr. There is also the option of an instantaneous system. These gas hot water systems are installed outdoors due to venting requirements but they can be installed indoors with a flue if need be with extra cost involved to. Most hws these days have an energy efficiency star rating where more stars the cheaper it is to run. What i have noticed that everything not just hws but everything that is energy efficient and the more stars the dearer it is too. You will have to do you own sums to work out what is better for you.
Some units have a pilot light which uses a small amount of gas as said above or have electronic ignition which is more economical. With the electronic ignition one if there is a black out no power no hot water. Only on the instantaneous heaters you can get what they called hydro as well. Instead of pilot light or having electronic system from power of battery the hydro makes it’s own power to spark the ignition cleaver hey. Liquid petroleum gas (LPG) bottles are an alternative to natural gas but expect to pay significantly more in running costs.
Cost: They range in price from about $700 to $2000 not including install costs
Solar Hot Water System
Solar hot water systems consists of solar collector panels and a storage tank. Some brands have tank sitting on the ground next to the house with say a 250 ltr tank and the panels sit on the roof. They call this style a split system solar hot water service and uses a pump to circulate the water to heat up. On average a four-person household typically needs about four square metres of solar collector area (two panels) and a 300 ltr tank. Of course depending where you live and the average sun shine per day over the course of the year. You need a large tank to allow for days with less sunlight or more hot showers than usual. Ideal panel location is facing north east or north west and if this can’t be achieved in an ideal location they may be less efficient and you’ll need a larger collection area. The storage tank usually has an electric or gas booster element to keep the water hot on days with less sunshine. They are more expensive and time-consuming to install and depending which brand and style to get. With the style with tank and panels on roof once the tank and collectors are full there is a lot of extra weight there and roof needs supporting. For the record i’m very skeptical about solar hot water systems with the price of them and and time frame they last but a well-chosen system will pay for itself in the long run due to very low running costs. Government rebates and other incentives can help offset the purchase cost. Check your local and state government for more information about solar rebates
Cost: They range in price from about $2000 to $7000 not including installation or any parts
Heat Pump Water Heater
A much more efficient form of electric storage tank system that works on the same principle as a reverse cycle air conditioner is the solar heat pump water heater. They work by extracting heat from the air and using it to heat the water tank. These units are very heavy and usually integrated with the tank and compressor together but can also be split system with a separate tank and compressor. They need to be installed in a well ventilated area usually outdoors with just like any air-con system. The compressor on the unit can be noisy like the outdoor unit of an air conditioner so location of the unit can’t be install too close to a neighbouring home or to a bedroom window.They tend to work best in warm and temperate regions but there are models designed to work well in cold climates to. Most systems have a booster element which runs on electricity for days of cold weather or high demand. Standard sizes are around the 270 ltr–315 ltr tank for a four-person household.Government rebates and other incentives can help offset the purchase cost.
Cost: They range in price from about $2500 to $4000. Installation is much same as electric storage tank
Storage tank or instantaneous heater?
The next decision after deciding what heating method is whether you go for a system with a tank or one that heats water instantly.
- Most electric, gas, solar and heat pump hot water systems use a tank.
- Mild-steel tanks can corrode over time so maintenance needs to be done every few years depending on water quality can help prevent this. They usually have five- to 10-year warranties depending brand and style.
- Stainless steel tanks are more expensive, but generally last longer and don’t require as much maintenance as mild-steel tanks. They usually carry a 10-year warranty, but still require occasional maintenance such as replacement of valves and seals.
- Local water quality may dictate to you which type is best for you.
- Tanks are insulated but there is always some heat loss over time so it’s good to install them in a sunny spot or in an insulated space.
- An instantaneous HWS heats only as much water as you need when you need it.
- Most models use gas but can get electric models aswell.
- As there are no heat loss like with stored tanks they’re often cheaper to run than storage systems.
- Electric models will use the full electricity tariff for whenever they are in use so running costs may be higher than for an off-peak tank.
- The size you need (flow rate in litres per minute) depends more on the number of hot water outlets the heater has to serve than on the number of people in the household. As a general rule, for a two-bathroom house you need a flow rate of about 15–24 L/min. Talk to your supplier to find the right capacity for your home.
Household size and water usage
One person can use about 50L of hot water a dayand more if you use your dishwasher oftenor take very long hot showers. Washing in warm water in the clothes washing machine can make a difference in water consumption too .
Get a hot water system supplier to analyse your home and usage and recommend some options. To determine the right size heater a supplier should ask how many people live in your home. How much hot water you use and when you use it. For an example do you all shower in the morning or evening? Do you wash clothes in hot or cold water?
For most households, a solar hws maybe be the most efficient and cheapest to run but If that’s not an option here are some other suggestions:
- Small household 1-2 people and gas able Instantaneous hws or small gas storage hws.
- Medium household (3-4): Gas systems instantaneous or storage or a heat pump.
- Large household (5+): Multiple instantaneous hws may be an option but gas storage units may be more economical. Large heat pumps are also an option.
Energy star ratings
Gas hot water systems have energy efficiency star rating labels. The more stars the more efficient the water heater and the more it will cost. The highest rating is six stars.
Minimum Energy Performance Standards currently apply for electric hot water storage systems. MEPS are currently under consideration for other water heater types. This will eliminate inefficient models from the market and may see star rating labels appear on all hot water systems.