Right Hot Water System for Townsville's Tropical Climate

Hot water is the second-largest energy guzzler in the average Australian home, so picking the right system is important to make sure your power bills don't spin out of control.

To help you make the right decision for yourself, we have broken the process into eight simple steps:

1. Use your current system to narrow your choice between a like-for-like replacement or an upgrade.
2. Pick the most efficient energy source – choose between electric, gas, solar, or heat pump.
3. Choose between tank and tankless systems – decide if you want storage or hot water on demand.
4. Understand your household's hot water demand to size the system based on people and shower habits.
5. Evaluate your roof and space situation to check for physical constraints and structural strength.
6. Factor in Townsville's tropical climate – ensure your system can handle salt air and cyclonic winds.
7. Compare upfront cost vs running cost to look at the long-term savings rather than just the price tag.
8. Consult a pro to get an expert site audit to confirm everything works.

Let's walk you through each of these steps to ensure you select a system that's reliable,  cost-efficient, and correctly sized to meet your family's hot water demand.

Step 1: Use Your Current System to Narrow Your Choices

Looking at your existing hot water system helps you narrow down your options before you start comparing models. 

First, note the type of system you're using now, like electric, gas, solar, or heat pump: If you're happy with its performance, a like-for-like replacement is usually the simplest choice because it works with your existing power supply and plumbing. But if running costs or efficiency have been an issue, this is your cue to consider upgrading to a different system type.

Next, check the age of the unit on the manufacturer's label: Systems nearing the end of their typical 10-year lifespan are usually better replaced than repaired. At this point, it's better to upgrade to a more efficient option because you're already planning a full replacement. Yes, it will cost more due to new wiring or plumbing, but it's often worth it for long-term savings.

Finally, look at the size and position of your current system: This tells you what capacity works for your household and whether a new system can fit in the same location. If your hot water demand has increased or the space is limited, this can guide you towards a larger tank, or a continuous flow system for a compact upgrade.

By understanding what your current system does well, and where it falls short, you can confidently choose between a simple replacement or an upgrade that better suits your home and lifestyle.

Step 2: Pick the Most Efficient Energy Source

Hot water can use around 25% of household energy in Townsville, so picking an efficient energy source to heat the system is one of the simplest ways to lower your bills.

Heat Pumps

A heat pump is a reversed air conditioner. Instead of releasing heat like an AC unit, it pulls heat from humid, tropical air to warm your water.

In Townsville, the air is always warm enough, averaging 25 to 31°C, to provide free heat even in the middle of the night. This constant warmth allows them to stay at maximum efficiency 365 days a year. 

Solar PV Synergy

If you have solar panels, you should be using your own energy. Instead of selling your extra solar power to Ergon Energy for a small 8.6-cent credit, you can use that energy to heat water during the day and store it for use at night. Using your solar power this way is much smarter than buying expensive electricity at 33 cents from the grid at night.

Gas Systems

Gas units are a great option if your home already has a natural gas connection, as these units provide endless hot water. 

But if you rely on LPG cylinders for the gas supply, which are twice as expensive as piped gas, it won't be a good option anymore. Plus, you'll have to pay for bottle rental and delivery, which adds further to the cost.

Electric Storage

Electric storage is often the best choice for emergency replacements if you are on a tight budget. These units are the cheapest to install but the most expensive to run.

If you choose this energy source, ask your plumber about connecting the unit to Ergon's Tariff 33. It's a dedicated economy circuit that supplies cheaper power for about 18 hours a day. This keeps running costs down without the higher upfront price of other systems.

Step 3: Choose Between Tank and Tankless Systems

In Townsville, your choice usually comes down to two options – a big storage tank or a compact on-demand system. Each has a different impact on your water pressure and your electricity bill.

Storage Tank Systems

A storage tank is like a giant thermos. It keeps a large volume of water hot and ready for you to use. 

This is the most common choice for large families because it handles the morning rush very well. If you have two showers running at the same time while the washing machine is on, a storage tank provides the best water pressure across all your taps.

Choose a tank system if you are on Ergon Energy's economy tariffs. These tariffs offer significantly lower electricity rates. The tank heats the water during those low-cost windows and then retains it for later use. 

Please note that these systems lose heat when water sits idle and use extra energy to reheat it, which raises your bills. And once the tank runs out, you'll need to wait for it to heat up again.

Continuous Flow (Tankless) Systems

Continuous flow systems do not store any water. Instead, they heat the water through a small coil as soon as you turn on the tap. 

In Townsville, these systems are very efficient because our "cold" water is not exactly freezing cold, so the unit doesn't have to work as hard to heat it. The downside is they can struggle with pressure if several taps run at once – your shower might lose flow if someone starts the laundry.

For smaller households, a continuous-flow system is a space-saving win that delivers endless hot water on demand and ensures you only pay to heat what you actually use.

Step 4: Understand Your Household's Hot Water Demand

Getting the size right of your hot water system is super important because, 

• If the unit is too small, you will be stuck with a cold shower halfway through. 
• If it is too large, you waste money by heating water you never use.

To find the ideal size, a good starting point for storage tanks is to allow for 50 litres/person/day of hot water. This covers average showers, doing the dishes, and general cleaning. 

• For a 1–2 person household, a 125L–160L tank is usually plenty.
• For a standard family of 3–4 people, you should aim for a 250L–315L tank to handle the morning rush.
• If you have 5 or more people, you will likely need a 400L unit or a high-flow continuous system.

Beyond just the number of people, you need to look at how your family actually uses water. 

For example, you'd need to size up if

• Multiple people shower at the exact same time every morning in your house.
• You have teenagers who take very long showers. 
• You frequently use a large soaking tub, which can use over 150 litres in one go.

In these cases, a larger tank ensures the last person in the queue isn't left in the cold. This is also where a continuous flow system with a higher flow rate works great because the supply never runs out. 

On the flip side, you can save money with a smaller system if your demand is low. This usually applies to 1- or 2-person homes where both people shower at different times. 

If you have modern, water-efficient appliances and fixtures, you can comfortably choose a smaller, more affordable unit. This keeps your upfront costs down while still providing all the hot water you need.

Step 5: Evaluate Your Roof and Space Situation

In Townsville, many homes are surrounded by dense trees or have unique layouts that leave very little room for bulky equipment. This means the actual physical space available in your yard or on your roof often dictates which system you can realistically install. You have 3 possible situations here:

1. If you have ample roof space: Go for solar, as you'll need 4 to 6 square metres of clear, north-facing space to capture enough sun. Keep in mind that a full roof-mounted tank weighs 300 to 400 kg, so your roof structure must be strong enough to handle the load.

2. If the roof space is limited or shaded: Use your yard space instead. A heat pump is a great option here, but it needs proper ventilation, so don't put it in a shed or corner. The compressor hums like an air conditioner, so it's best placed away from bedroom windows to avoid noise.

3. If your yard space is narrow or restricted: Opt for a continuous flow system. It mounts on an external wall and fits neatly into tight side passages.

A quick walk around your home will usually show which option best fits your layout.

Step 6: Factor in Townsville's Tropical Climate

In North Queensland, humidity and storms can be tough on the equipment, so you need a system that is built to last in tropical conditions.

Townsville is in Wind Region C, a cyclonic zone where rooftops must handle winds up to 250 km/h. Any system on your roof – solar panels or a heat pump – needs cyclone-rated frames to stay secure in storms.

If you live near the coast, like in Bushland Beach or Pallarenda, salt air is a big factor. 

Salt settles on your unit and fittings, which speeds up corrosion. Standard tanks use a sacrificial anode rod to prevent rust, but Townsville's salty, humid air causes these rods to deplete much faster. A stainless steel tank is often better here because it is naturally rust-resistant.

Our intense sun can also be a problem, sometimes heating water to near boiling. 

To stay safe, your system needs a tempering valve. This simply mixes in a bit of cold water so the hot tap stays at a safe 50°C, preventing nasty burns while keeping the tank hot enough to kill bacteria.

Townsville's humidity is actually a bonus for heat pumps. Because the air is consistently warm and humid, these units operate at peak efficiency throughout the year. 

Step 7: Compare Upfront Cost vs Running Cost

It is tempting to just grab the cheapest unit on the shelf, but the sticker price is only half the story. You have to look at the total cost over the next decade. The cheapest system to buy is almost always the most expensive one to run, and vice versa.

To help you compare, here is a breakdown of what you can expect to pay for the unit and installation versus what shows up on your power bill each year: