7 Reasons to Choose Tankless Instant Hot Water
We all try to save water but there are times when all you want is to enjoy a nice, warm, leisurely shower.
Why Choose a Tankless Instant Hot Water System?
A Virtually Endless Supply of Hot Water
They save energy and money
Compact design saves space and looks better
They have reduced emissions, as higher star ratings equate to lower CO2 output
Longer lasting designs
Cleaner and fresher water
Healthier and safer designs inhibits bacteria growth
Instantaneous (Instant) Gas Hot Water Systems Prices
Instantaneous (Instant) gas hot water systems are typically priced from around $700 to $1500*.
The price difference depends on the flow rate which is, in turn, dependent on the number of showerheads and taps.
Storage tank style gas hot water heaters range in size from around 130L to 350L, with prices from approximately $800 to $1450*.
Efficiency star ratings also influence the price, with higher star ratings typically cost more in both types.
*Note that prices are indicative only, as of October 2018
Guilty Pleasures in Limited Supply
Let’s admit it... most of us like to indulge occasionally.
Living in the country and depending on tank water, I do try to wait for a big storm when the rain water tank is overflowing in any case.
Makes me feel less guilty!
However, I’m not the only one in the family with that idea.
My wife likes to run a full bath and others are ready to take advantage, too.
We would have a problem if we were relying on a storage tank water heater, with a limited supply of hot water.
The problem would be even worse if we had an off-peak electric water heater.
Somebody would end up very disappointed.
The good news is that there is a simple solution to the problem.
Tankless instantaneous gas hot water systems provide a continuous flow of hot water.
In fact, there are seven reasons that you should consider going tankless:
1. A Virtually Endless Supply of Hot Water
Traditional storage tank hot water heaters can only heat a certain number of litres at a time.
Most residential hot water heaters are in the 135L to 170L range.
Off-peak electric units need to be considerably bigger, because they have to last through the whole day.
Once all of that pre-heated water in the tank is used up, it needs a recovery period to get the fresh contents back up to an acceptable temperature.
If it runs out mid-shower your only choices are to finish with a cold shower or to stay soapy while you wait for the water to reheat.
You’d be soapy for quite a while.
With a tankless hot water system, the water is heated as you need it and it can maintain the flow rate indefinitely.
So, no running out of hot water no matter how many family members line up for the shower.
2. Save Energy
When you eliminate the large tank, you also save all of that energy being used to maintain the temperature of the stored water 24/7.
In contrast, within tankless hot water systems the burner only needs to run when the hot water is actually needed.
3. Space Savings
Removing the bulky storage tank saves space.
At about the size of a small suitcase, tankless water heaters are a fraction of the size of a traditional storage tank heater.
The smaller tankless units are also more aesthetically pleasing, as it doesn’t dominate the exterior of your home.
4. Reduced Emissions
Greenhouse gas emissions are reduced through the use of tankless water heaters.
Tankless hot water heaters come in LPG or natural gas models.
Tankless gas hot water systems produce about a third of the greenhouse gas emissions of electric storage hot water systems.
5. Longer Lasting
Traditional storage tank water heaters have a life span of around 10 to 12 years.
Tankless hot water systems can last up to 20 years.
6. Cleaner & Fresher Water
Water from a storage tank water heater may pick up bits of rust and scale that build up within the tank.
Since there's no tank to rust and no water stored with a tankless system, the water stays cleaner and fresher.
7. Healthier & Safer
With tankless systems, you only need to heat the water to 50°C, as the prevention of bacterial growth is NOT an issue with tankless units, as it is with all of the other alternatives that have tanks.
So, less chance of scalding and no breeding ground for Legionnaires’ disease, or Legionellosis, that is caused by a bacterium, Legionella pneumophila.
It is a respiratory disease that can cause severe pneumonia and is sometimes fatal.
How a Tankless Water Heater Works
• Cold water flows into the water heater when a hot water tap is opened inside your home.
• The water flow is detected by a sensor that ignites the gas burner, to heat the water in the heat exchanger.
• The water typically follows a serpentine pattern through the heat exchanger, absorbing as much heat as possible.
• An electronic control unit modulates the gas burner to maintain a set water temperature.
See all the details on:
Hot Water System Sizing?
Don't Calculate by Number of People or Bathrooms
The sizing information available is very confusing because manufacturers, and others, are trying to provide a simplified answer to a complicated question.
Some suggest that you calculate by the number of bathrooms in your home while others say to go by the number of people in your family.
Also, in many cases, their recommendations are based on the worst case scenarios, assuming higher consumption than your actual water use.
Buying Too Large Wastes Money
The result is that many people end up buying a larger system than they actually need.
This costs them extra money when they buy the hot water system and will increase the ongoing operating costs, in many instances.
Factors to Really Consider
Simultaneous use is one of the fundamental determining factors.
The number of people in your home combined with how and when they use hot water is the key.
Do they all take showers at the same general time of day?
Do they take showers simultaneously in different bathrooms?
Do the showers have WELS 3 Star Rated Showerheads (maximum 9L/Min) or standard 18 to 25L/Min showerheads?
Do some prefer baths, which use more hot water? Is the bath or spa oversized, requiring even more hot water?
Do you run the washing machine, using hot or warm water, while people are showering?
Is your dishwasher connected to the cold or hot water? If hot, do you use it while hot water is being used elsewhere?
Showers Are the Key
Showers use the most hot water in a home. People generally shower for 5 to 10 minutes.
Assuming you have a 3 Star shower head and you mix in some cold water with the hot, the typical hot water consumption would probably be in the 7 litres per minute range.
If you also assume an 8 minute shower, you will consume about 56 litres of hot water per shower or a family of four would consume 224 litres.
The use of WELS (Water Efficiency Labelling and Standards) 3 star rated showerheads is an important factor in saving water and energy whilst reducing the size and cost of the hot water system required.
Hot Water Tank Example
In the above example, if all four people take their showers in the morning, you would only need a storage hot water system with 224 litre first hour capacity, regardless of how many take showers at exactly the same time.
This all presumes that you are not using any other hot water devices at the time.
The use of additional hot water, after the shower period, would depend on the hot water system’s recovery time required to achieve full temperature.
So, with a larger family or house guests, a bit of scheduling may be required to avoid the need for a larger unit.
Off Peak Electric Issues
Off peak electric storage units are a completely different story.
Inasmuch as they only heat water at night, they need to be quite large to make sure you don’t run out of water during the day.
So, some of the electric savings is offset by the fact that you need to heat a larger tank.
The bigger tank would also cost more to purchase.
Tankless Hot Water Example
For a tankless continuous flow unit, it would depend on how many showers are being used simultaneously.
Using the example above, if it’s two showers, then you only need a unit with a minimum flow rate of 14L/min.
If you have 3 people showering at exactly the same time, you would need a minimum 21L/min.
This does assume that you are not using other hot water devices simultaneously.
Recovery time is not an issue with continuous flow units, so even a large family with guests would not run out of hot water.
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The information in this article is derived from various sources and is believed to be correct at the time of publication. However, the information may not be error free and may not be applicable in all circumstances.