Frequently Asked Questions
Do I need to buy an expensive heat pump to work at minus 15ºC? How cold does it actually get in NZ?Kent Bio-Filter Heat Pumps operate right down to minus 15ºC ambient (outdoor temperature). This is more than adequate to maintain efficient operation as the coldest temperature recorded in New Zealand since 1979 was in Waiouru at minus 10.5ºC back in 1994. There is no need to spend extra money on other brands of heat pumps that cost more to work harder at low temperatures, these expensive designs are simply not necessary. The coldest regions in New Zealand typically have average temperatures of between minus 4 and 7 ºC. Download the report below to see the minimum temperatures recorded siince 1979 in our coldest regions.
How does a Heat Pump work?
Heat pumps work by controlling the pressure of a special refrigerant gas using a continuous tube running between indoor and outdoor units. The indoor unit controls the rate at which air is moved around the room and signals to the outdoor unit how much warm or cold air is needed in the room. When compressed, along a coiled part of the tube in the outdoor unit, the gas heats up and the tube then warms any air passing by. To understand how compressed gas heats things up, place your thumb over the end of a bike pump and force the air out - your thumb will soon feel hot as the compressed air squeezes out along your skin. When allowed to expand along a coiled part of tube in the outdoor unit, the gas cools down and the tube then cools any air passing by. To understand how evaporated gas cools things down, hold a spray deodarant close to your armpit and then allow the compressed gas to evaporate - your armpit will soon feel cold up as the compressed liquid rushes out and expands. By reversing the cycle of the gas pressure, you can have hot or cold air inside your room. NZ heat pumps are designed to work predominantly in heating mode as our climate is predominantly cold (in Australia heat pumps are designed to work predominantly in cooling mode). When used for heating indoors, the outdoor unit will be cold. This is why heat pumps lose a bit of their efficiency in very cold weather as the coiled tube can sometimes freeze. Heat pumps will go into a defrost mode to quickly defrost any ice building up.
What size and type of Heat Pump should I consider, and are some features really necessary?
Consider the size of the room to be heated – larger rooms require greater power capacity on the heat pump. The Energy Efficiency and Conservation Authority requires an Energy Ratings Label to be fitted to identify the efficiency of units. See our Q&A about the possible confusion regarding new and old rating labels. We question the use of self-cleaning filters on heat pumps as the dust and microbes are basically being blown back into the room. This recycling of contaminants is defeating the whole object of having filters fitted. It makes sense to remove any filters and clean them outdoors into a bin. Some Heat Pumps use electric heaters to keep the outdoor coils from freezing when the tempaeratures drop, allowing them to operate at minus 15ºC. Our temperatures never get this cold. The coldest temperature recorded in New Zealand since 1979 was in Waiouru at minus 10.5ºC back in 1994. These expensive designs are simply not necessary. The coldest regions in New Zealand typically have average temperatures of between minus 4 and 7 ºC. Buying a unit and installing it yourself is not recommended – installation to our specifications is imperative for the Kent warranty to be valid. You’re also more likely to get the right type of unit and best location for your requirements if you get advice from an installer. If doing a new build then consider a whole home ducting unit with the heat pump installed in the roof cavity and vents inbuilt into ceilings. Options run to wall units, floor units, ceiling units or fully ducted – choose the most suitable for your space and house design. You can buy a single unit for one room, or a multi-system unit for two to four rooms. Your electrician will check if your power supply can handle the power demands. Check how loud the unit is – some indoor units can be noticeably intrusive. Your local council may have maximum noise restraints in place for outdoor units.
Do Happy Home products meet government regulations for emissions and AGA gas efficiency ratings and are they registered in the EECA Energy Wise programme and Clean Heat projects?
Many Kent wood fires and gas fires are approved for use and are registered in the EECA Energy Wise programme. The Ministry for the Environment has published a list of approved clean air wood fires. Kent wood fires are included in this list and Aber now manufactures all the listed Kent woodfires. Some local authorities (such as Canterbury, Nelson and Hastings) have specified more stringent clean air requirements and it is important to be aware of these in advance of purchasing a Kent clean air wood fire. The Australian Gas Association has published a list of approved 4 star gas fires. Models made by Sampford IXL are the models now branded as Kent (Cassel and Ochre). These are approved for use.
Will a wood fire heat my whole home?
The correctly sized unit for a home is important. Too large and it will be forever run on low causing poor combustion and creosote problems restricting the flue updraft. Too small and it will fail to generate sufficient heat to warm the area. Kent always recommend a site check of the home by a certified fire installer before installation. Bear in mind that while the heater may generate sufficient heat it then has to be circulated throughout the home. If the house doesn’t allow natural dispersal of heat (e.g. high ceilings, long hallways etc.) circulation can be improved with a ceiling fan or heat transfer kit.
Where is the best position for a heater in a room?
A radiant heater should be positioned so that it can safely and efficiently heat the people in its heat wave, so any objects that do not need heating (or are flammable) should be moved away. A convection heater will work better if the warm air currents it produces and circulates are assisted. Convection heaters should be placed near a wall that is closer to a doorway. The doorway draws the ground-level colder air towards it and it is this colder air that the convector wants to heat - rather than let it stay cool in your room. Avoid placing a convection heater opposite your windows, especially if you have no pelmet above curtains or blinds, as the warm air current will head straight for the windows and outside (glass transmits heat much quicker than walls and curtains).
What are the different heating costs between power, gas, LPG, pellets and wood?
The cost of providing heat (which is heat energy transformed from fuels) is determined by the fuel type, fuel quality, fuel cost and efficiency of the appliance used to make the heat. Using industry data we have estimated the differences for you. We have used the average energy efficiencies of appliances, the net calorific value (CV) of the fuels (the remaining energy available after any exhaust gases have been flued), and excluded standing/rental charges. The following are heating costs based on the fuel used and the type of appliance, the actual cost of the appliance has not been included. Generally speaking the more you pay for an appliance the cheaper it will cost to heat a whole home on a room-by-room basis. So you can compare the cost of heating a lounge, we have summarised different fuel costs and appliance efficiencies below: The least expensive is a heat pump, as one unit of electricity (a kWh) is converted into 3 kWhs of heat. Even though a unit of electricity is high compared to other fuels, it is the ability of a heat pump to convert this into heat (by 300%) that makes this the lowest cost. Heat Pump Power = 7.3 c/kWh Heat Energy (300% ee) 22c/kWh Next lowest is natural gas, as one unit of gas is low in cost and the efficency of most appliances are around 86%. NG = 8.8c/kWh Heat Energy (85% ee) 7.5c/kWh Wood Pellets = 10.5c/kWh Heat Energy (90% ee) 18GJ/t or 5000kWh/t, $475/tonne, 8% Moisture Content, 650kg/m3 Density, $475/5000 = 9.5c/kWh. Pine Firewood = 11.5c/kWh Heat Energy (65% ee) 15.5GJ/t or 4300kWh/t, $320/tonne, 20% Moisture Content, 250 kg/m3 Density, $320/4300 = 7.5c/kWh. LPG = 20.50c/kWh Heat Energy (85% ee) 46MJ/kg or 12.8kWh/kg, 45kg cyl = 576kWh, 45kg cost = $100, $100/576 = 17.4c/kWh Power used directly by 100% resistant electric heaters (oil-filled, radiant, convector etc) is the most expensive, simply due to the high unit cost of power. These are the cheapest heaters to buy, hence they are still used as a compromise when a home has not been installed with proper central heating. Power = 22c/kWh Heat Energy (100% ee) 22c/kWh
Can I control the amount of heat produced by a wood fire?
This is determined by the amount and quality of wood burned, the size of the logs and the fire design (efficiency, size of the fire box and the airflow controls). Airflow controls affect the rate at which the wood burns so some control is offered, however this also leads to choked air supply and this is when CO2 emissions and particulates are at their highest. Burning the right amount of (quality) wood in the firebox is key. Example: Say a firebox can take 7kgs of wood. If dry softwood is used, the CV will be 18Mj/kg and this will provide 126Mj of energy at one maximum time. Divide by 3.6 to give kW = 35kW. Factor in the fires efficiency loss (68.70%) you end up with 24kW of heat available. If you only half-fill the firebox then you get half of the above = 12kW (only burning 3.5 kg of wood). If the heat from your fire is used for a lounge only (not throughout the house) and you want to only produce 6kW of heat then the 7kg firebox should only be a quarter full (less than 2kgs of wood). A smaller firebox of 4kg will only be half full to provide 6kW of heat.
Should I leave a heat pump on all the time? and, Why is my heat pump so expensive to run?
If your heat pump was installed by a credible and knowledgeable installer, then you have probably been advised to never set your heat pump to the AUTO setting. This is the most important thing to do when using a heat pump. If it has been set on AUTO, and you leave it on all the time, the heat pump will always try to maintain the room temperature you have set it at - so if it is cold the heat pump will warm the air to reach the desired set-temperature, and it if the sun starts streaming in through the windows and the room temperature naturally increases above the set-temperature, then the heat pump will start to cool the air... costing you extra money and wasting energy. You should always ensure the heat pump is set to HEAT mode in winter and use the timer function to pre-set when you need heat, or manually switch it on and off. As a general rule, you should never leave a heating device on all the time as you do not occupy the room all the time. Commonsense will dictate how often you will be in and out of a room and sometimes it is worth leaving the heat pump on if you are returning to the room soon (otherwise you lose the heat in the room and have to re-heat it all again). We discourage the use of heat pumps in summer for cooling as it is very likely the NZ electricity network and generating stations will be unable to cope with the extra demand for power at a time when water reserves (and hydro-power generation) are low.
Is a ducted warm air system better than a combination of a heat pump and a ventilation system (like HRV or DVS etc)?
A typical Ventilation System costs between $3,000 and $5,000, it:
- Reduces condensation
- Freshens air
- Reduces dust build-up
- Does not provide effective heating
- Can fight against convection heating systems
For one Heat Pump to a heat a room, the cost is between $3,000 and $5,000, it:
- Reduces condensation
- Circulates and filters air
- Provides cooling in summer
- Does not heat a whole home
- Suffers from reduced heating output in colder weather
So for Partial Comfort you will be spending between $6,000 - $10,000 (100-160 sqm home)
Alternatively, you could consider the Bonaire Ducted Heating & Ventilation System for the same cost, it:
- Reduces condensation
- Circulates and filters air
- Reduces dust build-up
- Provides cooling-effect in summer
- Effectively heats a whole home
- Can heat different zones, at different times/temps
- Maintains heating output in colder weather
- Uses NZ natural resources more efficiently and effectively
- Is an Asthma Foundation NZ approved product
What’s More:
- Unlike Heat Pumps, there is no need to go into chilly defrost mode, plus you can enjoy quiet air distribution from many ducts not just one big blower
- Unlike Ventilation Systems, warm air reduces condensation, plus effective heating is provided efficiently on demand (you should not have warm air in your loft in winter in the evening as decent ceiling insulation should keep this heat in your rooms)
So to benefit from Total Comfort you could spend between $6,000 - $10,000 (100-160 sqm home).
Why should we use gas directly in our homes?
The Centre for Advanced Engineering has just published an independent report titled Understanding the Contribution of Direct Use of Gas to New Zealand’s Future Energy Efficiency Objectives. This highlights why we should be using gas directly in our homes. Copies have been sent to Government to help ensure the National Energy Strategy is reinforced by including direct use of gas. You can view this report on most pages of our website.
Can Bonaire Ducted Heating be installed in an existing property?
Over 1,000 existing homes have been fitted with the Bonaire Ducted Heating system. Depending on loft space or underfloor access, our installers can generally complete most installs within 3 days.
Where can I compare running costs, sizes and heat outputs?
In our Technical Specifications section and alongside specific products you can view and print Product Specification sheets containing the size, perfomance and running costs of all our products. There is a sheet for all Bonaire Ducted Products and a sheet for GEO, Pyrox and Paloma products.
Is the Bonaire Ducted System quiet?
The system is designed to operate at low noise levels. Our installers ensure the furnace is installed so that fan noise is kept to a minimum and the ducts are fitted to keep air movement noises low. User feeedback has been vey positive with people not noticing any noise.
How do I know if a Happy Home product is best for my new home?
On the Design Guide section of our website you will find a PDF document you can download to help you provide the right information for us to correctly advise on the best system for your new home.
Where do I find product specifications for Builders & Architects?
We have provided specifications for most of our products in the Technical Specifications section of our website. You may also wish to use our Contact Us facility and our Key Account Manager will be in touch with you.
If all hot water is used at once, will there be less for everyone?
It is important that our continuous flow water heater is sized correctly for a household. We calculate what could be the largest demand (litres per minute) in your home and size the unit accordingly. The number and size of hot water outlets influences this sizing.
How much gas is available in NZ?
Less than 4% of NZ’s gas is used in the home, there is over 25 years supply available and ongoing exploration is likely to extend for many years. In a recent survey we found out that only 3% of respondents thought we may have insufficient gas reserves.
How easy is it to get connected to mains gas?
If the natural gas piped network is in your street, your local gas company can arrange for an underground pipe to be laid from the gas network main in the street to your home. They will check resource consents from your local authority and advise on the timeframes involved. Depending on your location and the work involved, you may be connected free of charge.
How easy is it to get connected to LPG cylinders?
If your home is accessible for deliveries and within an LPG delivery zone, you can be connected. The advantage of bottled gas is that you pay only for the gas you use. A typical installation consists of two 45kg cylinders which are securely fastened to your outside wall to ensure a supply of LPG to your property.