Blog
Sun Lizard: any good?
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We've been getting quotes for heating in our house, as it's starting to get cold. Initially we thought we'd go for a flued, fan-forced gas heater in the fireplace in the lounge room. A friend has the unflued gas heater recommended by Choice and it's brilliant. Heats her whole house really well. We figured flued because then the exhaust gases go outside.
Turns out gas heaters of this calibre, flued or unflued, are around $3,000 or more plus installation. Not cheap! So we decided to have a look at ducted heating, which if it comes in at under double that, I reckon isn't a bad deal since it would heat the whole house.
Now I've found The Sun Lizard which was featured on New Inventors. It uses heat from the sun to force warm air in or out of the house, depending on the season, and stores the heat in the thermal mass of the house. Given we're in a double-brick house, we've got plenty of thermal mass.
This claims to heat by 4-6° which sounds like it'd probably be enough most of the time for us. In addition, it cools by up to 10° in summer which would be a nice bonus. At under $3,000 it sounds like a nice option, and with no ongoing costs it's quite attractive.
But I'm not sure 4-6° is quite enough, even in Sydney's mild winters. I vowed when we bought a house to never spend another winter shivering with all my clothes on and a crappy electric heater sucking down expensive juice. This is the experience of poorly insulated, unheated rental properties for about a month a year in Sydney.
I wonder if the money we were thinking of spending on ducted heating might be better spent on a unit like this and upgrading our insulation. Get the roof vacuumed and the old insulation replaced with modern, high-spec insulation. As an added benefit, it would reduce plane noise. We're also looking into double glazing, which has benefits for both thermal and acoustic insulation. Perhaps with greatly-enhanced insulation and this unit, we could get by with a crappy electric heater used for only a few days a year?
So does anyone out there have any experience with this unit?
12 May 2008 23:37 [category: /diy] #
Improving fridge efficiency
At some point over the next year we're planning to renovate our kitchen. We did a very minor renovation soon after we moved in, replacing the lino floor and swapping in an Ikea bench/drawer unit, but we want to do something much more extensive.
One of the things I've been thinking about is getting the best energy efficiency out of our fridge. I've always found it a bit odd the way they're designed. Fridges work by pumping heat from the inside out to the coils normally located on the back. Wouldn't it be much more efficent to arrange the fridge similar to a split air conditioner, with the heat-release coils in a cooler location? My basic understanding of thermodynamics makes me think the higher the difference in temperature between the liquid carrying heat from inside the fridge and the air around the coils, the higher the efficiency.
Along these lines, I was wondering if efficiency would be improved by getting cooler air flowing over the coils. Since our house has a raised, wooden floor, this could be done by putting a grill in the floor, so that the convection draws cooler air from under the house over the coils. Obviously there needs to be a way for the warm air to escape as well. This arrangement should result in something of a chimney effect, with cool air drawn in at the bottom, passing over the coils, then escaping at the top.
So I dropped a note to the Alternative Technology Association who publish the excellent ReNew: Technology for a sustainable future magazine. I expected, possibly, to get a response in the magazine at some point in the future. To my surprise, I received a response the same day from Technical Editor Lance Turner.
A number of people have suggested this mod over the years, however the most important thing is that air can escape from the top of the fridge - ie, the fridge has at least a 50mm gap between it and any of the walls of the alcove, especially the top of the fridge. So long as there is enough space for air to flow freely, you will get convection happening as the condenser heats up.
Lance goes on to suggest a forced-air fan to actually blow over the condensor, particularly if you can get it to work only when the compressor is on. Quite a neat idea, but I'm keen to go with a passive approach.
So it seems that my idea has some merit, but only if there's a good way for the heat to escape. I'll look into having the hot air vent into the roof space, as well as the vent at the bottom. I think that should result in some pretty substantial efficiency gains.
24 Apr 2008 14:56 [category: /diy] #
Weatherproofing
It's starting to get cold in Sydney, so we're starting to think about heating and improving the house a bit. The front door has enormous gaps all around, and there's space between much of the skirting boards. This weekend I'm gonna fix the front door with some kind of automatic weather strip, as well as the squishy stuff around the sides and top edges.
I'll also look at caulking some of the skirting boards to stop any draughts. I might also consider blocking up some of the air vents, which were only ever required for gas lighting ventilation. Holly won't be keen on the idea, but we might have to look at curtains with pelmets to stop heat loss out the windows. With the right curtains, it should also reduce noise from the planes.
Speaking of gas, we're gonna get our fireplace fitted with a fan-forced, flued gas heater. These things aren't cheap, but they're very efficient and I reckon one should be able to warm the whole house enough for our needs.
07 Apr 2008 12:06 [category: /diy] #
Mitre 10: You suck
Conversation had with a clerk at Mitre 10 (large DIY store chain in Australia) on Saturday morning:
Me: I'm after some 50mm 6 gauge screws with pan heads, stainless steel.
Clerk: (looks around the shelves a bit) No we don't have that. We've only got what's here. You probably need to try a specialist fastening store.
Me: What you mean like a hardware store?
Clerk: ...
WTF is Mitre 10 if not a store where you'd expect to find screws in various incarnations? How difficult would it be for them to have a small cupboard with many small drawers stocked with every imaginable type of screw? The profit margin on screws at retail must be enormous, so you'd think there'd be an economic incentive.
Mitre 10, you're no more than a jumped-up $2 shop these days. You suck!
31 Mar 2008 13:19 [category: /diy] #
Bathroom done (almost)
Well we're finally done on the bathroom, but for two small jobs. I need to paint the door, which I'm doing today, and we have to put up the shower screen. The wall to which we're attaching the shower screen is just a cavity wall, and of course the studs are not where the screen has to go. So we'll have to open up that wall from the other side and put in a structural stud to hold the (bloody heavy and pivoting) shower screen.
So it's pretty much done! We toasted it with some mates last night and some nice Chandon NV. Thanks Matt, Maz, Mikey and Leonie for putting us up while we were toiletless. Speaking of toilets, have a look at this lovely unit:
Right, I'm off to put the first coat on that door.
