Sunday, May 4, 2014

Preparing for an Australian winter

When you've lived over 35 years in 2 of the coldest cities on the planet the idea of feeling cold in Perth seems mad.  Outdoors is never an never goes below zero celsius and most days will still reach a high in the teens.  That said, after 2 winters here and approaching a third I have never felt so cold inside a house as I have in Perth.

The majority of houses here are built with an extremely simple form of insulation: air.  Houses have two layers of brick with an air gap in between.  Unless the house was build in the last 5 or so years it will have no insulation in the attic.  Regardless of build date it will have single pane / glazed windows.  This makes for a structure that gets cold fast and stays cold without significant heat input.

Heat can be provided in a number of ways:  
1) Centrally via either natural gas (I've never actually seen a house with this but I'm told it exists) or reverse cycle air conditioning (electricity).  Vents tend only to be in major areas.  You don't see them in bathrooms, closets or laundry rooms typically.  Ducted reverse cycle is the most comfortable year round solution in Australia.

2) Split unit reverse cycle air conditioners (electrically run) which will only heat or cool in the room their in.  If sized properly these work well and make for one of the most energy efficient solutions as the idea is you only turn them on when needed.

3) A gas point is provided in multiple places in the house for you to connect a gas heater which can be purchased for 900 to 1200 dollars each new.  A note of caution, these units are self contained and have no mechanism to exhaust gases such as carbon monoxide.  Houses are never equipped with carbon monoxide sensors.  I'm told that state governments have run campaigns in the past to try to get people to get rid of their old dangerous gas heaters in exchange for newer safer ones.   It is suggested when running these units that you have windows or doors open a bit to ensure ventilation.  One could suggest that the less than modern aussie construction techniques leave houses so loose in terms of air movement that this isn't a real problem.

4) A wood burning stove (Jarrah hard wood seems to be the fuel of choice and number of companies offer bulk home delivery starting around $150 per 1/2 tonne).  The heat is uber nice but of course you have very little control and they are not exactly low maintenance.

5) Bathrooms often have heat lamps which feel nice and would keep a roast turkey warm in a pinch.

I should mention that thermostats are also very rudimentary when compared to North America.  Those used to smart thermostats that set the temperature based on when you're home or awake might be disappointed. By contrast, split units allow you to set the temperature of the air coming out, and have timers.  Central ducted units allow you to set the room temperature and have timers.  Many systems are purely on or off.

So that all said, this year we've got a combination of available heat.  One split unit in the master bedroom.  A wood stove in the living room.  A gas point in the same room, and a gas point in the main kitchen / living area.  Kids rooms have...well...blankets.

I've ordered 500 kg of jarrah which showed up next day.  A lot of it is little tiny pieces so I'm not sure how long it'll last but it's dry and it definitely burns.  The reverse cycle in the master works really well.  I'm thinking we may add a gas heater to the house as a last resort if we get to a point that we can't get the majority of the house above 17 C. 



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