If anyone knows of an environmental friendly and cost effective heating device for a large open plan house please let me know. It must be easy to install, not too power hungry to kill our power supply from the solar system etc. I have been looking around as our fireplace sure makes a difference but it certainly does not ‘heat’ the house.
Some may, some may tell you, or themselves, that is the reason for it.
For many on the east coast it is their prime method of pasture management being cheaper and more fun than slashing, using weed wipers and using a variety of techniques to keep the grass density high and so exclude weeds. Some enjoy it, some do it because dad and granddad did it so it must be right and some like the green flush you get in spring after the first rains and think that is good work.
Burning also reduces the carbon content of the soil which reduces the nutrient and water holding capacity and it drives off volatile essential nutrients (such as nitrogen compounds). Frequent burning degrades soil.
When pasture is being grazed and is well managed the height of the grass should never get particularly long for long as that is when growth slows down and the aim is maximum growth for as much of the year as possible. You may get longer grass briefly in spring when it is growing fast but that will be green and moist and is not a risk of grass fire. Long, dry pasture that is a fire risk during summer is a sign of poor or no management.
In this country there is a case for burning at longer intervals in lower rainfall regions (the rangelands) where paddocks are huge and stocking densities are very low but that is not what I am talking about.
For energy efficiency a modern reverse cycle aircon is probably the best value for money. To do the whole house will probably require ducting as many smaller split systems is too pricey and less efficient.
There is no magic solution that does all the things you want and is also cheap to install. I don’t think you can legally DIY the installation so I am not sure why it has to be easy. If you can stand the up front cost, over time you will well and truly get your money back on power savings compared to resistive electric heaters.
Oil and gas heating you can forget as failing the environmental test and being much more expensive to run.
The topic looks to heating the home. Recognising all needs includes due consideration
Technology based on heat pumps (powered by electricity) provides an efficient way to deliver heat energy and cooling. Direct collection from solar is another heating option. Conversion of solar to electricity is central to Australia’s pathway to deliver a low emissions. Is this cost effective relative to other ‘Environmental friendly’ options? If there is a more cost effective alternative it remains to be invented.
Every home and location is different. The best solutions depend on making the most of the climate and design of the existing home. Some homes will be better suited than others. It’s a balance between upgrading the home and the total cost including the heating/cooling solutions. For some homes upgrading to a higher standard may be limited or very expensive. For those homes spending a little more on the heating/cooling solutions including running costs with less outlay on the home can be the most cost effective. That has been our pathway, with the relatively small added expense of a larger solar PV the solution.
Our experience is based on making the most of the assets of our current home. Maximising the use of natural ventilation, shading in summer, and reducing heat loss in winter. It’s not a home that was designed for a cold climate. It’s not a home that was intended for the sub-tropics, but features ventilated eves, high ceilings and steep pitched roof with open verandahs.
Hence ceiling insulation, and an ongoing project to reduce leakage when the splits are in use is money well spent.
When originally erected the timber home had an external brick chimney against an outside wall with (mantle & hearth) heating just one room. It did not survive an update by a prior owner.
We are discussing something different to the original topic when,
Observation and first hand discussion with those responsible for issuing fire permits or carrying out such tasks. The priorities are property and agricultural assets ahead of all else. Is there adequate consideration of the environment and impact on vegetation and wildlife? There are differing views across the nation.
Fireplaces are very inefficient in heating a home as most of the heat goes up the chimney - it relies on radiant heat to warm things.
Since you have a fireplace, there are options available for the space if you don’t want to lose the ambience of a fire. Options include pellet heaters, gas flame heater (with fans) or a modern fan assisted woodfired heater. These can be installed in fireplaces and will be significantly better/cheaper at heating that a traditional open fireplace.
If you don’t have high R rating insulation, I would also be considering installing this in the ceiling cavity as it will significant improve any heating (or cooling) used within the house. Without good insulation, a lot of heat/cooling will disappear through the ceiling substantially increasing heating/cooling costs and also reducing the efficiency of the heater.
If you install a heating system that doesn’t use the fireplace, make sure that you have the chimney sealed off. If you don’t it will be like having a window open as all the heat will vent through the chimney. Sealing off will also prevent pests/vermin using it as their doorway for entry to your house.
When looking at a heating option, look at their advantages and disadvantages. There isn’t a heating system that perfectly suits every need. Looking at advantages, disadvantages as well as cost will allow you to make an informed decision in relation to what is best for your own situation.
Not in my view as if you are switching away from wood burning you must approach the question of the alternative.
It’s always an option. It’s a similar but different comparison to those looking to move off gas. Many with gas have ducted systems to heat a whole home, and use gas for hot water and cooking. Most using wood likely only one area, some as a necessity, most not continuously or day long except on the coldest of days.
Heating using a wood fire is a continual chore. Well seasoned firewood provides around 20MJ/kg. How that equates to house hold heat output depends on how one burns it - open fireplace, wood heater, etc. The efficiency of an enclosed wood burning heater or stove can be as low as 50%, IE 2-3kWh of heat output for every kg of wood. Some boast 80% or higher. The older the appliance the less efficient and potentially dirtier the combustion.
While efficiencies of any heater can vary, a few years ago the Sustainable Energy Authority of Victoria looked at relative CO₂ contributions of common heaters:
This information is still relevant today. However CO₂ emissions for electric heaters can be possibly discounted by 15-20% based on change in generation profile since 2002 (as more renewable generation occurs today). Reverse cycle air-conditioning is also more efficient. One could assume that with discounting based on efficiency gains and CO₂ reductions, emissions could be in the order of 30+% less for the reverse cycle air-conditioning using grid power.
As indicated above, each heating method as advantages and disadvantages. Sustainability Victoria provides some good information on advantages and disadvantages of different heating types:
@dieterfb may find the information useful when looking at replacement of their traditional fireplace with a more effective heating system.
Thanks @phb , very interesting and helpful.
If you decide to replace your fireplace with a modern relatively efficient slow combustion wood heater, some models come with fans, for air circulation. The efficiency of your heater can be augmented also by using in conjunction with ceiling fans on the winter setting to flush the warm air through the house.
Why is this so? What is the price difference? And how is it less efficient? Has Choice done this testing?
I’ve 6 split systems at my residence (4 bedrooms, 2 living areas) in Brisbane, so mainly cooling and some heating in July. I just have on whichever area is occupied and they go on standby/lower power if nobody is detected after a certain time. Over the (10) years some have failed and the cost of replacement is low compared to the initial cost, and was done in a few of hours.
As a general comment each split costs from roughly $1,000 to $2,000 each these days (Metro Vic) to install. The higher amounts include typical sparky work to add individual breakers as required by standards.
This is complex and depends on use patterns and personal preferences. To start with I was assuming the requirement was to heat/cool the whole house.
If you only want to condition only a few rooms the individual systems are cheaper to buy and (because by default they can be turned on or off as required) cheaper to run. However some ducted systems allow individual room control so that is not always so.
If you do want to condition the whole house you would have to cost the purchase and installation cost of both approaches in your situation. Accessibility for ducting would come into this. Any comparison I have seen makes several assumptions that may not apply to you and is often covered with caveats saying your mileage may vary.
On running costs I am having trouble getting a clear answer on the thermodynamic efficiency of both approaches assuming for the whole house. I was told by a aircon mechanic that all other things being equal larger compressor/fan units are more efficient than smaller as there are overheads. I realise that is just hearsay but I can’t do better right now.
There is also the questions of aesthetics and control. Duct outlets are far less obtrusive than the internal units of split systems and you can control the whole house centrally (or even remotely) with ducted.
As far as I can see Choice has not done a head to head comparison, probably because of the variables and complexity involved.
Since we are talking in the context of replacing fireplaces and either many split systems or one ducted is a fair bit of cash I feel we ought to also mention passive climate control. Spending some money on insulation, verandahs and other wall shading and extra glazing may be well worth it in the long run. If you are going to splash some cash it is wise to consider if just replacing the heater is the going to give you the most comfort and economy. It doesn’t matter if you go split or ducted if the house is badly insulated you will be wasting huge amounts of money over the years.
If you peruse split systems specifications the EER/COP (efficiency) goes down as the unit capacity increases in product dependant steps.
Why is that? Is it a consequence of basic physics or manufacturing and marketing issues? Does it bear on the comparison of the two approaches? I don’t know. Many of the discussions of the comparison are vague on this question and some don’t go past the point that split systems can be turned off when one room is not occupied. Some “experts” will tell you split systems are cheaper as they are smaller (duh!).
@BrendanMays does Choice have an expert available who can get involved here? Is this topic worth its own thread?
Traditional fireplaces are very inefficient. Most of the heat goes straight up the chimney and out while sucking cold air in to replace it. We got a slow combustion stove insert that fitted nicely in the fireplace. The difference in heat was amazing. However, that was before they restricted in operation of slow combustion stoves because of emissions. However, I believe they are still pretty good.
In any case, before you think of a heat source, you need to consider the energy efficiency of your house otherwise you’ll be just blowing dollars out the window. Look at how you can increase insulation in the ceiling, roof and walls. Consider double glazed windows and sealing and air gaps under doors etc.
We do have some experts that specialise in heating, but I’m not sure whether they have investigated these aspects in detail. I appreciate the suggestion, it’s an interesting topic, so I’ll flag it with the appropriate teams for consideration.