Water Heating: Maximising Efficiency

Water heaters can often use a lot of power and are one of the biggest factors in your power bill however there are several ways to increase the Energy efficiency of your Hot Water System and therefore Saving energy at home. A standard storage water heater i.e. the hot water Cylinder can be either Mains pressure or Low pressure.

A low-pressure Hot Water Cylinder will deliver a lower volume of hot water than a mains pressure hot water Cylinder, which will deliver hot water at a similar volume and flow rate to your cold water supply.

What this means is that a Low Pressure Hot water Cylinder will generally cost less power than a Mains Pressure Hot water Cylinder, Saving on energy bills but at the cost of lower pressure and flow hot water.  

Eco-Friendly Plumbing Practices

There are a number of alternative hot water systems to the generic Mains pressure and Low pressure hot water cylinders. 

The Heatpump hot water cylinder adopts heatpump air conditioning technology to heat the water inside the storage hot water cylinder instead of drawing power from the grid and often in some situations require zero power at all to operate the appliance.

This makes the heatpump Energy efficiency superior to a number of other hot water heating options as it is re using existing heat from the ambient atmosphere to heat the water inside the vessel, also making it very eco-friendly.

The heat pump does have a couple of location restrictions mainly related to climate as it will require a minimum of 2 degrees Celsius to function and would not work efficiently bellow these temperatures or frost prone areas. 

Another Eco Friendly Hot water option would be the Solar Hot water Cylinder. This technology has been around for many years and has proven to be very energy efficient and eco friendly however is not very common in New Zealand due mainly to the cost of installation and some consent requirements.

There are ways to modify some existing hot water cylinders and add a computer of sorts, which will detect the existing temperatures and be able to be adjusted so that the Cylinder is turned on and working according to how the computer has been set at.

What this means is that the energy savings could be increased a lot as you are able to set the Cylinder to only heat the water for Peak hours of every day.

Wetback hot water cylinders would be some of the oldest Hot Water Systems in New Zealand that would be considered energy efficient and potentially eco-friendly.

They operate basically by having a flow and return pipe enter both the cylinder, and the back of a fireplace. The flow and return pipework will act as a heat exchanger, absorbing heat from the fire and transferring heat to the water inside the cylinder.

Typically the older installations were connected to wood fires which as we know are not considered Eco-Friendly however some newer installations may come under that category. Regardless of this, the wetback heating system is an old, but highly effective way to save energy. 

There are several other eco friendly options for hot water heating out there that may be worth considering.

Do energy saving devices really work?

This all depends on what device, and the way it is integrated into the hot water heating. Flow restrictors can be installed at every fixture to the house where required. They will limit the volume of water per second to a set volume as rated on each restrictor. This means it would be impossible to use more hot water per second than what is rated on the restrictor and therefor it would work in saving energy.

Limiting valves can be adjusted to limit pressure and therefore water per second so ultimately work as a flow restrictor of sorts however have less control over each individual appliance. These limit valves are recommended to be installed to the cold water supply at the entry to the building which means it will limit the pressure to the entire house. Often the older houses with older plumbing systems do not have these limit valves at the start of the building, however it is a mandatory requirement that a limit valve is used with the installation of a Mains pressure Hot water System so one will always be located at the mains pressure hot water cylinder if not located at the water entry to building. 

How to save energy at home?

Understanding your homes plumbing system.

Having a good knowledge of how your plumbing system works could work out to save you a lot in energy costs.

How long is everyone taking for their showers? Do those showers have flow restrictors fitted? The longer the shower, the more hot water is used, and potentially the more energy costs are accrued.

What appliances do you have that are using hot water? And how energy efficient is that appliance?

Single Lever mixers or Faucets you can control the volume of water coming out of the tap. These are the most common types of taps found in our kitchens, bathrooms and laundries today.

Sometimes to save energy costs is to just have more control over the water you let out of the taps when you operate these Mixers. Only using the amount of water required for the task instead of going full pressure could make a world of difference. Also think about whether you require the hot water.

These mixers can go full cold water meaning no draw on the hot water supply at all, meaning no energy cost. Sometimes this is worth considering as it is easy to forget these small things that may actually work out to be cumulatively significant savings. 

Plumbing Maintenance:

Fixing Leaks: Small Repairs with big impact

It is recommended that regular maintenance is undertaken on your plumbing system. Plumbers should undertake routine maintenance at least once every 6months. There are many reasons for this. One reason is that without regular maintenance the plumbing system could rapidly deteriorate, inevitably costing a lot to repair.

Also routine maintenance gives plumbers the opportunity to identify any faults or leaks. These faults or leaks could be dangerous if left to deteriorate, or they could be costing you regular energy spending.

A common example would be the Hot water Cylinder relief valves. Most systems have one or two of these valves and potentially they could be causing large energy costs if left faulty and uncheck. It is recommended that the homeowner does not tamper with these valves at all and leave it to the plumber as these are safety devices.

Even a leak on the hot water pipe left unchecked can cost a lot in energy, just another reason to get routine maintenance carried out on the plumbing system.