Energy Efficiency & Renewable Energy

As central heating will provide all the heating for your house, and possibly all the hot water too, specifying your system to be energy efficient can have a major impact by reducing your energy bills and carbon footprint.

You can do this by specifying:
■ Renewable fuel
■ Energy efficient boilers or heat pumps
■ Energy efficient control features
■ Low energy use components
■ Monitoring energy use

Specify renewable fuel
Electricity, Wood Pellets, Bio-Diesel or Log Fuel

■ New Zealand’s electricity is 65% renewable. When used by a heat pump with a high coefficient of performance, heat with a very low cost and very low carbon footprint is produced. Central Heating New Zealand offers geothermal and air to water heat pumps.

■ Wood pellets and wood fuel provide what is sometimes called ‘carbon neutral’ fuel, which even with transport included is a very low carbon fuel which is also cost competitive with other fuels.  CHNZ sells Woodpecker wood pellet boilers (right) and Attack log boilers.

■ The Firebird diesel boilers marketed by CHNZ can also burn bio-diesel instead of normal diesel. Ask at the design stage if you want this feature.

Energy Efficient Boilers

■ All boilers sold by CHNZ are efficient in burning less fuel to produce more heat.  There are however very high efficiency boilers called ‘condensing boilers’ that extract so much heat from the flue gases that the water vapour in the flue gases condenses, hence the name.

■ The Baxi Luna3 HT gas boiler, natural gas and LPG, is a condensing boiler with a stainless steel heat exchanger. 

■ The Firebird Enviromax boiler (right) is the condensing version of the Firebird diesel boiler range.

■ CHNZ recommends and sells flue gas analysers which ensure the boiler is running at optimum efficiency when it is commissioned.

 

Heat Pumps

■ The air-to-water and geothermal heat pumps sold by CHNZ produce 3 to 4 kWh’s of heat for every kWh of electricity used.

■ Geothermal heat pumps are the most efficient as they take heat from 2m underground where it is still warm in the winter. The image to the right shows the installation of underground geothermal pipe loops.

■ CHNZ are actively engaged in monitoring installations using this new technology to learn more about how to make it work best in New Zealand conditions.

Low energy control systems

■ The objective of any heating control system is to automatically heat the spaces that need heating without using any excess fuel which would overheat rooms and waste fuel.

■ Some controllers have extra features such as optimum start and open therm control technology.

■ Honeywell programmable thermostats sold by CHNZ allow the user to select optimum start mode.  This means that the controller learns how long it takes the house to heat up in the morning and switches on the boiler at the latest time possible for the house to heat up before the household gets up in the morning. On a milder morning the heating will come on later saving fuel.

■ All the Baxi gas boilers come with a comprehensive heating and hot water controller and can change the amount of heat provided by the boiler according to the load – called modulation. 

■ Using Open Therm technology the controller exchanges information with the boiler and tells the boiler to run at a low temperature in part load conditions. 

■ Gas and diesel boilers run more efficiently at lower temperatures, particularly the high efficiency condensing versions.

TRVs

Any radiator system fitted by CHNZ will use Thermostatic Radiator Valves (TRVs) on each radiator.These switch off the radiator they are on if the temperature in that room reaches the temperature selected on the TRV.  This allows occupants to save energy by turning down rooms they are not using and energy is saved when a radiator in a room heated by the sun is turned off by the TRV as it is not needed at that time.

Low energy use components

A lot of new central heating installations in New Zealand are underfloor which in bigger installations can use several pumps for circulating the hot water through the various pipe loops. CHNZ supply Grundfos Alpha pumps (right) which are European A rated for energy efficiency. They are able to sense the pressure and reduce the flow in a system where controls have turned off some of the system to save energy.

Running at a lower flow rate reduces the power used, and the Alpha pumps also use permanent magnet DC motors which are twice as efficient as conventional AC pumps.

Energy Use Monitoring

Keeping an eye on your energy use helps identify waste and provides crucial information if you are considering a new heat source. All CHNZ systems are hydronic, (use water to carry the heat from the heat source to where it’s needed), meaning a simple heat meter can tell you how much energy you are actually using.  See www.logit.co.nz for heat meters.

With a heat meter you can also sell heat from your heat source to tenants for heating and hot water, enabling more people to benefit from your energy efficient or renewable energy system.  Metering the energy used makes sure tenants pay for what they use which discourages energy wasting.

Learn more about Energy Efficiency

The EECA (Energy Efficiency & Conservation Authority) encourages, promotes and supports the uptake of energy efficient initiatives and renewable energy in three key ways.
1. Helping businesses and consumers to get more from their energy dollar
2. Improving lifestyles through warmer, drier homes and better personal transport choices
3. Protecting the environment by supporting the use of renewable sources of energy.

For more information on the EECA and its initiatives go to www.eeca.govt.nz or check out www.energywise.govt.nz for info on energy choices in the home.