Frequently Asked Questions – Part 10

Answers to commonly asked questions.

Q- Is the Hydrotherm still classed as solar?

A- The Hydrotherm generates STC certificates just like a solar hot water system, because both are classified as Green Technologies. The difference is that a solar hot water system uses direct sunlight captured either through panels or evacuated tubes. The Hydrotherm uses a heat pump to capture the solar energy from the surround atmosphere.A well setup Solar system will be perhaps 10% more efficient then a heat pump over the course of a year, but heat pumps have a number of other advantages.

Q- What liter capacity are your hydrotherm heat pumps?

A- We have two models the Volt is 170L Dynamic – 275L

Q- I want to use as much from the Solar Power system at my house during the day, apparently they can put the hot water on a timer any hot water system really , but the solar specialist suggested a heat pump. There is 3 people in the home.

A- With the 3 people you should be fine to have the Volt only heating during the day off the solar P.V. If you go to 4 or more people I would suggest the Dynamic if you want to maintain heating solely during the day. What you need to do is make sure that the system is installed on Tariff 11 (continuous tariff) and then set the timers from say 10:00am – 16:00pm when your solar P.V should be producing power. The system draws down .8Kwh when running so you want to have a 1.5kwh or larger solar array to ensure that a 100% of power is coming from Solar (this will give a little leeway for cloudy days

Q- I notice the information says it heats the water to 60deg but I thought water had to be heated to 70deg to prevent legionnaire disease.

A- No Legionella is controlled a number of ways the most common is to ensure that a minimum of 50% of the stored tank water reaches 55 degrees daily. How we achieve this is by having the temperature probe located 3/4 of the way down the tank with a 10K dead band i.e the system drops from 60c to 50c before reheating. 70c is only referenced for gas boosting or when the water is only exposed to heat for 1-2 seconds.

Q- Do you know what a typical installation cost would be? Would it be more than a regular electric hot water system? A- No there is no additional plumbing required to install one of our systems as compared to an electric hot water system but you should allow $100 – $200 for additional electrician fees to install an isolated switch.

Q- I would like to find out. i’m using origin T31 at the moment. my family always shower in the morning. do we needs to change to T33?

A- Yes you will have to change from T31 to T33 or alternatively T11. We suggest T33 as this is cheaper and still provides sufficient power supply. The system will function at a higher efficiency if it heats up in the morning after your showers rather than in the late evening before your morning showers
Also if there is a service call we would not be able to access the system as there would be no power supplied to the unit during daytime operating hours.
The STC modeling is also done on Tariff 33 so legally we can not allow the system to be connected to Tariff 31. No heat Pump to my knowledge is actually modeled or certified for T31 connection

Q- Do you deliver to Sydney?

A- Yes we do if you enter your postcode in the shop it will give you the system price including delivery.

Q- I’m looking at replacing my electric hot water to a cheaper one? How good is Hydrotherm

A- The Hydrotherm will use around 70% less energy than a standard electric hot water system so they can save you a lot of money off your power bill. Because of the government STC rebate they also cost around the same as an electric hot water system so it is quite an easy choice.

By – Simon Baird 

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