Sizing A Hot Water Heater

12 / 10 / 2020

In order to make your investment operate as efficiently as possible you should select the correct size of water heater. As Summer approaches, you may be considering which water heater is the most appropriate for your needs. You may consult the following guide to residential water heater sizing.

NSW Hot Water supplies and installs hot water heaters with over 10 years’ experience in the industry. We operate all over Sydney, The Central Coast and Wollongong. We provide professional and courteous service at every call out we get to.

Tankless and Demand Type Water Heaters

Sizing a tankless or demand type water heater can save you time and energy when making a purchase. The most important metric to consider is the maximum temperature rise at a given continuous flow rate. Consequently, you need to calculate the flow rate and temperature rise you’ll need for application of the water.

Flow Rate: Consider the maximum number of outlets you need connected to running hot water. The flow rate is the sum of the flow rates of each hot water outlet. Simply add up the litres per minute required of your hot water outlets and there you have it. The answer is the given flow rate you’ll need for your hot water heater.

For example, a hot water faucet and a shower running at one time require 2.84L/m and 9.46L/m, respectively. Therefore, the flow rate you would require from your water heater is 2.84 + 9.46 = 12.13L/m.

Efficient appliances like shower heads can be purchased to reduce the flow rate required to operate at maximum capacity. This can help you to save on your water usage each quarter.

Temperature Rise: To work out temperature rise, subtract the incoming water temperature from the desired output temperature. Incoming water temperature is the temperature of the water at the main. In Sydney, it’s safe to assume that incoming water temperature is approximately 18 degrees celcius.

For a shower in the morning, use you will want water at a temperature of about 49 degrees celcius. In this case you would need a demand water heater that produces a temperature rise of 31 degrees celcius. Other uses requiring additional heating, for example dishwashers or washing machines may require temperatures of 60 degrees celcius. This would require a temperature rise of 42 degrees celcius.

Solar Hot Water Heating System Sizing Guide

Solar hot water systems save on energy bills. Sizing a solar powered hot water system requires calculation of the total collector area and tank size you will need. All solar system assist you in meeting your household’s water needs during the summer.

Collector Area: Solar hot water contractors usually use two square metres of collector area for the first two family members. For every additional person, add 0.7 square metres.

Tank Size: The size of hot water system you need will depend on the number of people living in your home. A small storage tank is usually enough for 1-3 people. A medium storage tank is appropriate for 3-4 people and a large tank best for 4-6 people.

Active systems require an increase in volume of the tank for every increase in size of solar collector. Typically 6L of storage volume for every square metre.

Contact NSW Hot Water Today

NSW Hot Water supplies and installs a diverse range of hot water heaters across the greater Sydney, Newcastle and Wollongong regions. You can see what we have available elsewhere on our website. We are also happy to answer any questions you may have when you call.

Call us today on (02) 9722 4500 to place an order for tankless or solar hot water system. We’re open for business Monday to Saturday, 24 hours per day.