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»Energy myths
MYTH #1: Bottled LPG gas is cheaper than electricity
Burning bottled LPG gas in an unflued gas heater is more expensive (approximately 28 cents per KWh) than running a standard plug-in electric heater (approximately 21 cents per KwH). CEA does not recommend the use of unflued gas heaters. Click here for more information about why.
Bottled LPG gas for a flued heater or central heater costs between 22-30 cents per kWh.
Source: 'Consumer', 5 June 2008.
MYTH #2: It's cheaper to keep heat pumps running all the time
Having electric heaters running, even on low, when they are not required is wasting energy. Only use heaters when required. It usually requires more energy to keep a room at a constant heated temperature than to heat it only when you are in the room. You can use timers on most heat pumps to pre-heat the room just before you need it.
MYTH #3: Using a unflued (portable) LPG gas heater and a de-humidifier is an efficient heating option
Running a de-humidifier to soak up the water vapour given off by unflued (portable) LPG heaters doesn’t make ‘cents’! Unflued LPG heaters is more expensive than a conventional electric heater, and you have to pay for the cost of running the de-humidifier as well.
»What to do about condensation
If you have excessive condensation in your house, the first thing you need to do is find out the source of the problem:
- Are rooms kept well ventilated? Good ventilation this allows air to circulate and any excess moisture to escape
- What is the indoor temperature? Very warm and very cold temperatures both lead to increases in condensation
- Do you have an unflued gas heater? These release about one litre of moisture into the air every hour they are used.
- Is your bathroom and kitchen fitted with an extractor fan vented to the outside? This will remove condensation created when showering and cooking etc.
- Where do you dry your clothes? Drying clothes indoors will increase condensation and dampness. Using a clothes dryer which is not vented to the outside will also make your home very damp.
- How many pot plants do you have? They will produce as much moisture as they take in when watered. Fish tanks can increase the humidity in your house as well!
- Is the ground underneath your house damp? Moisture can rise up through the floorboards.
- Are north facing windows shaded? Increased shade reduces natural heat absorption from the sun.
You could then consider adopting the appropriate measure(s) to alleviate the problem:
- On dry days open windows to allow air to circulate. Keep windows closed on wet days as damp air will increase indoor humidity.
- On cold days keep indoor temperatures at least 7°c higher than outdoor temperatures. Use thermal or lined curtains, keeping them open in the day and closed after dusk. This will maximise the capture and maintenance of natural warmth and will reduce the number of cold surfaces on which moisture condenses.
- Don't use unflued portable gas heaters. If you must use a portable gas heater ensure the room is well ventilated.
- Dry clothes outside or in a well ventilated room, with doors closed to the rest of the house. Ensure the clothes dryer is vented.
- Fit extractor fans in the bathroom and over the stove top in the kitchen.
- Limit the number of pot plants in the house
- Install polythene to the ground underneath the house. This will help to prevent damp air rising up into the house. CEA can provide this service.
- Cut back vegetation shading north facing windows.
Dehumidifiers and ventilation systems can help reduce air moisture, however they do not solve the underlying problem. They are also expensive to run.
»Heating choices and costs
The World Health Organisation recommends a minimum temperature for living areas of 18°-21°c for living areas, and 16°c for bedrooms. Choosing the right heating for your house is dependent on many considerations including the age and size of the house, which rooms you want to heat, the health and age of the residents and the set up and running costs of each heating type.
Use timers and termostats to heat your home efficiently
Other points to consider when choosing a heater
Sizing a heater
For each type of heater you need to consider the room size:
A rule of thumb calculation to choose a heater which is an appropriate size for your room:
1. multiply the width X height X length (in metres) to get the volume of the room in cubic metres (m3).
2. multiply the volume by 60 to get the heating requirement in watts (W). This is for Christchurch conditions.
e.g. A room has a 3m stud, and is 4m wide and 5m long. The volume is 3x4x5=60m3. Heating requirement is: 60 X 60 = 3600W. Therefore a 3.6kW heater is needed (1000W=1kW).
- If the room is uninsulated, draughty, or has a large area of external wall or large windows, it will require a larger heater (up to 20% more).
- If it is well insulated with ceiling, wall, floor and window insulation, it should require a smaller heater (up to 25% less).
- For comparisons of installed costs, efficiencies and running costs see the table at the end.
Use timers and thermostats to heat your home efficiently
Use timers and thermostats to control heating. Some heaters have these built in but you can also buy them separately. Heat the area you need, keep doors closed to maintain heat in ‘living areas’. Turn heaters off when they are not being used, this includes oil column (fin) heaters and heat pumps.
Types of heating
Advantages | Disadvantages |
Cheap to buy and install Instant heat 100% efficient i.e. all the energy is converted into heat A clean form of heating No extra labour (shopping for gas refills, chopping wood etc). With a thermostat the temperature can be controlled accurately Many have timers | More exposure to fluctuating electricity prices |
Advantages | Disadvantages |
Work with Night and Day power plans and use power at night on the cheaper rate to make heat. The heat is stored in the heater (in bricks) until 7am, when it is released during the day. Day time warmth at night time prices A clean form of heating Good if people are at home during the day
| Considered 80% efficient because sometimes they waste energy by providing heating when it is not required. Little heat is left for evenings They don't emit heat at night Higher purchase and installation cost than regular plug-in heaters You must decide the night before whether you want heat the next day |
Advantages | Disadvantages |
Can heat a large area Very cheap to run Provide 'atmosphere' Can take advantage of fallen trees and other forms of free fuel A wetback can be fitted to heat water
| Not clean - smoke produced pollutes the air |
Advantages | Disadvantages |
More energy efficient than logburners Burns cleaner than logburners, resulting in better indoor and outdoor air-quality Less preparation of fuel and cleaning involved Greater control of temperature Can still heat a medium/large area effectively Has ambience of a 'real' fire A wetback can be fitted to some models | Requires handling and storage of 20kg pellet bags Some clearing (of ashes) involved Reliant on a limited number of manufacturers for the fuel source. Require electricity to run - emergency generator/battery pack required for emergencies Operation produces some noise |
Advantages | Disadvantages |
Heat pumps take heat from outside air and put it into the room. It also can be used in reverse as an air conditioner to keep inside air cool in summer. They are 200% to 300% efficient i.e. give out more than they use. Clean source of heating. Even with a fan, they are considered suitable for people with asthma as heat pumps filter the air. Low running cost
| Standard Hi Wall heat pumps not ideally suited for the older style Christchurch villas with high ceilings. Expensive to purchase and install. Efficiency drops when outside temperature drops below 2 degrees Celsius. |
Advantages | Disadvantages |
Clean form of heating Some can support a wetback system They give a high heat output Cheaper to run than gas or electricity | Expensive to purchase and install Exposed to variable price of diesel |
Central Heating (Gas/Diesel/Electric)
Advantages | Disadvantages |
Heats whole house Can provide hot water Heat controlled thermostatically and by a timer Can adjust temperature/ turn off heat in unused area of the house | Very expensive to install Diesel tanks require a permit Fuel access - transported via diesel tanker or in 45kg gas canisters, may be a problem in some areas Ground source heat pumps require a large area of ground to be dug up for pipe installation. |
Advantages | Disadvantages |
High heat output Instant heat Clean heat. The level of heat can be controlled more easily than with a log-burner. Don’t create dampness and health problems like portable gas heaters. Gas bottle re-fills are paid for up-front rather than getting an electricity bill at the end of the month. | More expensive to install than electric heaters.
|
Although common we cannot recommend these in any circumstance for the following reasons:
- They release up to 1 litre of condensation into the air, per hour of use.
- They work by combustion which draws in oxygen from the surrounding air, and releases water vapour and carbon dioxide into the room.
- They get less efficient as they get older, which can lead to carbon monoxide (a toxic gas) being released.
- Due to the above reasons, any room where a portable gas heater is being used needs to be well ventilated.
- Using portable gas heaters in bedrooms is extremely dangerous and is strongly discouraged. This is because bedrooms are often small and poorly ventilated. People who are asleep will not be able to respond to any poisoning symptoms. The Gas Regulations require that gas installations are installed in accordance with a set of essential safety requirements in Part 1 of the NZ Gas Installation standard (NZS 5261). Part 2 of the standard is considered to be a means of compliance with Part 1 and it prohibits the installation of (fixed) unflued heaters in bedrooms & bathrooms.
- The high radiant heat output can be a fire risk if placed near to combustible material such as curtains and furniture.
- They are banned in several countries.
Other Points To Consider When Choosing a Heater
Safety
• Electric convection heaters (e.g. fan or oil column heaters) are safer than radiant heaters (e.g. bar heaters) as the heat is not so intense.
• Solid fuel heaters need a fireguard with children.
• For gas heaters a fireguard is recommended with children.
• With portable heaters ensure that it does not tip over easily, or has a cut out switch.
Health
• Fans may trigger asthma by stirring up dust.
• Old portable gas heaters can give off toxic fumes.
Noise
• Heaters with a fan may be noisy.
• Convection heaters creak and click.
Radiant or convection heat
• A radiant electric heater (e.g. bar heater) is good for heating a small area in a large room or a quick burst over a short period. Disadvantages are the exposed element hazard and uneven heat zones.
• A convection heater (e.g. fan or oil column) heats air currents and provides background heat. It is slower but can be used with a thermostat.
Ease of operation
• Check that the heater controls are accessible and it is clear how to use them.
Fuel storage
• Log burners require a covered space for wood to be stacked and dried.
• Flued gas heaters require a space for gas bottles.
• Diesel heaters need space for a diesel storage tank.
Servicing
• Consider parts availability.
• Is there a guarantee or warranty?
Ease of Installation
• If a wetback is required is the fire near the hot water cylinder?
• Is there space for the flue?
• Log burners and pellet fires require space for a hearth.
• Will the heater fit comfortably into the room?
Portable or fixed?
• Do you need a heater that can be moved from room to room, or is a fixed heater appropriate?
Independence from electricity
• Some gas and diesel heaters and most pellet fires require electricity for ignition.
»Energy price comparison - running costs for different heating appliances
The following table gives a comparison between installed costs, efficiencies, and running costs for different heating appliances (August 2008).
Fuel | Heating Type | Energy Efficiency | Cost (to install) | Capacity (kw) | Fuel cost (av)* $ | Cost: $ per kWh | Cost per hr ($ per kWh x capacity (kw)) |
Electricity | Fan heater | 100% | $30 | 2 | 0.21 | 0.21 | 0.42 |
Oil column | 100% | $30 | 1 | 0.21 | 0.21 | 0.21 | |
$190 | 2.4 | 0.21 | 0.21 | 0.50 | |||
| Radiant (bar) | 100% | $35 | 1.5 | 0.21 | 0.21 | 0.31 |
$140 | 2.4 | 0.21 | 0.21 | 0.50 | |||
Nightstore | 80% | $1050 | 2.5 | 0.15 | 0.18 | 0.46 | |
$1150 | 3.4 | 0.15 | 0.18 | 0.62 | |||
Heatpump (wall) | 300% | $1,700 | 3.2 | 0.21 | 0.07 | 0.22 | |
$2,650 | 8.6 | 0.21 | 0.07 | 0.60 | |||
Heatpump (floor) | 300% | $2,400 | 3.4 | 0.21 | 0.07 | 0.24 | |
| $3,400 | 8.3 | 0.21 | 0.07 | 0.58 | ||
Heatpump (central) | 250% | $2,900 | 5.6 | 0.21 | 0.07 | 0.39 | |
| $15,000 | 15 | 0.21 | 0.08 | 1.25 | |||
| Central ground-source heat pump | 400% | $30,000 | 15 | 0.21 | 0.05 | 0.78 | |
Gas |
Flued gas
| 68%
| $2,700 | 4.2 | 2.65 | 0.30 | 1.28 |
$3,300 | 8.2 | 2.65 | 0.30 | 2.50 | |||
| Unflued gas | 90% | $185 | 4 | 3.18 | 0.28 | 1.10 |
$196 | 6 | 2.28 | 0.198 | 1.19 | |||
Gas Central Heating | 95% | $12,000 | 15 | 2.65 | 0.22 | 3.27 | |
Solid fuel | Logburner - wood | Free-standing 79% | $2,845 | 16 | 60.00 | 0.05 | 0.73 |
| Enclosed 68% | $3,295 | 14 | 60.00 | 0.05 | 0.74 | |
Wood Pellet | Pellet Fire | 85% | $4,000 | 5 | 0.47 | 0.10 | 0.52 |
| 85% | $5,000 | 10 | 0.47 | 0.10 | 1.04 | |
| Central heat-pellet | 85% | $18,000 | 15 | 0.47 | 0.10 | 1.56 | |
Diesel | Diesel - cabinet | 93% | $4,500 | 9.5 | 1.44 | 0.16 | 1.48 |
| Diesel - central heat | 95% | $14,000 | 15 | 1.44 | 0.15 | 2.29 |
*electricity = price per kwh (inc GST)
*gas = price per kg
*wood price per m³
*pellets price per kg
*diesel = price per litre
»Appliance running costs
For a list of appliance running costs, visit "Consumer" at http://www.consumer.org.nz/, then go to:
Appliances > Prices & reliability > Appliance running costs
»Borrow a Centameter and learn how to save money on appliance running costs
The Centameter is an innovative electronic device which measures the amount of electricity being used and displays the cost per hour on a portable display located in the home. The Centameter encourages you to save power by constantly monitoring how much electricity you are using and how much it is costing. By knowing which appliances use a lot of electricity, you can adopt new energy saving practices and reduce your power bill accordingly. We require a $20.00 refundable deposit. Non-community service card holders will pay a fee of $20.00 plus the refundable deposit. The loan is for 7 days - if you are interested give us a call at (03) 374 5698.
Please note: A Centameter requires an electrician to install due to safety reasons. See http://www.centameter.co.nz/index.php for more information.
We also have 'Alto' power meters for checking individual appliances.
»Guidelines on arrangements to assist low income domestic electricity consumers
The Electricity Commission has developed guidelines for electricity retailers on how to work with low income consumers. These guidelines are advisory rather than regulatory, and are intended to provide choice for electricity consumers. They are designed to ensure that minimal disconnections occur, and set out a clear process for retailers to follow if a disconnection does have to take place.
Retailers are to offer consumers having difficulty paying their bills a number of alternatives to standard monthly billing. These alternatives include prepayment metering, smoothed payments, and redirection of income. Bonds can cause undue hardship and should not be used unless certain circumstances (specified by the Commission) require the retailer to do so. The amount of the bond should not exceed $150 and should be refunded after twelve months of the consumer paying all bills on time.
Consumers with health and/or disability issues may face additional challenges if their power is cut off. The Commission defines these consumers as ‘vulnerable’ and advises that electricity retailers must have a process which enables vulnerable consumers to identify themselves to their retailers. This includes verification from a third party such as a GP, budgeting agency, or Work and Income. Vulnerable consumers should also be able to identify one or more preferred contacts (including social agencies) who have agreed to assist them if disconnection is pending.
The guidelines have been developed to avoid causing unreasonable credit risk for electricity retailers. They are intended to be complemented by a protocol between retailers and social agencies. The Commission will monitor the performance of this guideline and if the uptake is not satisfactory, there may be a need to regulate.
CEA views the guidelines as a positive step towards ensuring a transparent, constructive relationship between low income consumers and their electricity retailer. Many low income consumers struggle to pay the cost of staying warm during colder months but are able to meet this cost over a longer period of time under different payment options. The challenge for electricity retailers will be to implement these guidelines in a way that is user friendly for their customers.
To obtain a copy of the guidelines, click on the link below, or call the Electricity Commission at 04 460 8860.
Guidelines on arrangements to assist low income domestic electricity consumers (68KB)
Do you still have questions?
The Home Energy Advice Centre provides free, impartial expert advice on home energy issues over the phone. The Home Energy Advice Centre is open Monday to Friday 10am to 4pm. They can be contacted on 0800 388 588.