Ventilation louvre hassles

I specified wooden louvre blades

This louvre window installation is described in this earlier post.

Photo of louvre for night purge

Louvre now fitted with glass blades

The automated louvre window that I specified for my system of summer cooling by nocturnal purge had wooden louvre blades of western red cedar 14 mm thick.
I specified wood because I preferred that this louvre should not be transparent, as I did not want to see through it and I did not want it to admit light. I took the risk that wooden blades might not seal as well as advertised.
Other posters on the ATA forum (see link below) doubted that the blades would seal effectively. They were right.

Failure of the wooden blades to seal

When the louvres were closed for the first time, there was clearly no seal at all. The rubber seals fastened to the blades failed to meet the matching blades, leaving gaps of up to 2 mm admitting daylight.

Attempts to rectify

I wrote a letter of complaint on 18/5/2016.
Rectification work on warranty first revealed faults in the gallery of gearing at the side of the window. However, when the gallery was replaced the gaps remained. The photo shows daylight visible on the right side through three of the gaps.

Photo evidence that louvre does not seal

Wooden louvres showing daylight

As the blades did not meet their specification, the company replaced them without charge. When these new blades did not seal any better, the company offered (on 10/10/2016) to replace them with aluminium blades, 6 mm thick. I reviewed the specifications of their blade options, and decided that this was not acceptable. The aluminium blades had little thermal resistance (U-value: 6.55). Glass blades 6 mm thick, with a low-e coating had much higher thermal resistance (U-value: 4.40), almost the same as the wooden blades (U-value: 4.39). The company agreed to provide these low-e glass blades. (In fact, this had been their original suggestion.)

Sealing of glass louvre blade gaps

Continue reading

House in a cold October

This October has been very cold. That has kept indoor temperature
in this solar-passive house almost too cool for comfort. I wore warmer clothes and opened windows to admit warm air.

Indoor/outdoor temperature scatter-plot.

The climate this October

The graph shows (on the x-axis) how cold this October [in red] was: the coldest of the new century.
Here on the North-west Slopes of NSW, October warms and cools more from year to year than other months. It is the month most affected by climate cycles such as the El Nino-Southern Oscillation (ENSO). As shown, October warmed by one degree each year from 2011 to 2015, then cooled by nearly six degrees from 2015 to 2016.
ENSO followed almost the same pattern, but October 2012 was warmer than October 2013.
For five months, world temperature has also been down: much lower than it was in the record-breaking months of February and March 2016. (HadCRUT4 Global monthly near-surface data set (Column 2 in the linked table.))

Indoor climate this October

As shown on this graph beginning 2005, the indoor mean temperature in October months has varied with outdoor mean temperature. This coldest October outdoors (15.9 degrees) was also the coldest indoors (20.8 degrees). (But see Note below.)
October is the final month that I keep the house in its winter warming regimen. In 2014 and 2015 it had been almost ideally warm, but in 2016 it was just above the comfort minimum. Since this figure is just an average, there were times when the house was too cool for comfort, especially in the mornings.

Successive unfavourable months this year

As in other seasons, I intend the indoor climate to be comfortable through each spring season.
As I posted in “Hard Winter for Solar-passive” this very cloudy winter had reduced solar gain, making heaters needed much more than usual. However, the mean indoor temperature at winter’s end (August) was normal, although the heat bank was 0.7 degrees cooler than normal.
In September months, the warmth indoors still depends on solar gain through the north windows. This time,the sky continued very cloudy, and the daytime temperature was a record low value. As a result, the indoor temperature was 0.9 degrees down and the heat bank 0.7 degrees down.
By October, there is no solar gain through the north windows: warmth is gained from the surroundings in daytime by conduction, convection and radiation and retained by closed curtains at night. This time, both day and night temperatures were three degrees below normal, reducing daily heat gain and increasing nightly loss. As a result, the indoor temperature was 1.2 degrees down and the heat bank 0.9 degrees down.

What I did

Continue reading

Solar-passive House Testimonials

Photo of a birthday party in the solar-passive house

Birthday Group

Family members visited the solar-passive house in Monash Street, Manilla, NSW, in Mid-winter 2016. The date of their visit is shown on the graph in this earlier post. This photo shows us dressed for comfort at 17 degrees indoors.

Interviewer:
What do you think of Grandpa’s house in winter?

Grand-son (10):
I like Grandpa’s house. It’s nice. Except there’s no wifi. But apart from that, it’s good.

Grand-daughter (13):
Grandpa’s house? It’s cool. It’s interesting. Awesome curtains – I get a shock when they move because I’m not used to it. The garden is cool too – it’s pretty.

Daughter:
I love winter. And I love visiting my Dad. He built this really great house in Manilla nearly twenty years ago. Prior to that, he was tenanted in an old office space above the newsagent. I loved visiting him back then as well, even if his flat was super hot in summer and not at all cosy in winter. The house he built is wonderful all year round.

Even if there are only a few hours of sun each day in the depths of a NSW winter, that is all you need to warm my dad’s house. You can find yourself a chair in the sun, sit for a while and imagine you’re on vacation in Hawaii. Only with much better coffee. As the sun goes down, the sound of noisy birds settling in for the night comes through from outside.

Kitchen view SW

Kitchen view SW

The kitchen is well-stocked for preparing dinner (especially after we restock it) and, once the stove is on, it’s toasty warm in there. There is a curtain that closes the kitchen off from the rest of the house, but cooking time is social time for us, so we leave it open – which also helps flood the house with the delicious smells of curry. The house finally gets coolish sometime after dinner. That’s when we don the cardies and fluffy slippers and pre-heat the beds. The electric blankets, even on low, manage to warm the bedrooms all night.

Next morning, on a strict schedule, the automatic curtains fly open to announce the new day. Not being an early-morning person, I make good use of the curtain override button. At least, until I get the first whiff of toast.

Son-in-law:
Having grown up in India, I find summer is a breeze and cold weather is a challenge. After a couple of decades in Canberra and almost a decade in Switzerland, I have finally realised that dealing with winter boils down to managing the environment in the house and wearing the right gear.

I have stayed in my father-in-law’s house in Manilla several times, in summer and in winter, most recently in the winter of 2016. The house is comfortable in both summer and winter. I remember feeling colder in winter when I first stayed there compared with now – I am not sure whether the house is warmer, or I have more layers of fat to protect me as I get older. Maybe I just dress more appropriately now for winter thanks to my time in Switzerland.

The place where we hang out the most is the kitchen, and around the kitchen table, over cups of coffee or improvised meals, catching up on left and right leaning newspapers. The kitchen is very cozy in winter, especially when there are multiple dishes cooking away on the stove.

A memorable feature of my father-in-law’s house is the automated curtains which felt space-age when I first experienced them, but now I am used to them. They are like a bell-less morning alarm. Being a morning person, I beat them to it, and am awake before they start moving and letting in light.

Photos of porch awnings adjusted for outdoor living in winter and in summerI love the balcony on the first floor. It is well protected and I can sit there for hours with a cup of coffee and a book, and listen to cockatoos and other birds, and watch the paragliders in the distance when they are out. In winters the mid to late afternoons are the most comfortable.

Photo of a path between trees

In the garden

As the trees and shrubs in the evolving garden have grown and the paths have become more structured it has become a wonderful place to walk around and to relax. The garden bench is particularly inviting. This man is as passionate about his garden as he is about his house. The guided tour of his garden is one of the highlights of our stay there.

Interviewer:
Thank you all for your answers.
Goodnight, everyone.


Recent photos of the house and garden are here.

My Heat-control Courtyard

Photo of a small courtyard

A Heat-control Courtyard

I have added a courtyard to my high-mass solar-passive house to improve summer cooling and winter heating.

Photo of building materials

Courtyard Wall Panels and Gates

The courtyard extends 13 metres along the south wall of the house. It is completely enclosed by a wall of white-painted polystyrene sandwich panels 1.8 metres high, with two gates of the same material.

By September 2015 trenches had been dug for the courtyard foundation, and by December it was complete.

Photo of trenches dug for courtyard

Courtyard Trenches, West

Photo of trenches dug for courtyard

Courtyard Trenches, East

Operation

This house is in BCA Climate Zone 4: Hot dry summer, cool winter. For comfort, it must be made very much cooler in summer and very much warmer in winter. The courtyard was built to help to achieve both results without the use of heaters or coolers.
In summer, it should ensure a supply of very cool air at night. In this house, cool air is drawn in to replace warm air that flows out the clear-story windows by the stack effect, assisted by fans. By day, the courtyard walls also block some solar radiation.

Photo of courtyard from the west

The Courtyard Through The Western Gate

In winter, the white courtyard wall reflects sunshine north towards the house, and re-radiates heat lost from the house wall back towards it.

More

Much more detail is given in the page “A Heat-control Courtyard”. All photos on this topic are in a gallery in “House Photos – 2016”.

New Post on Wicket Gates

In August 2017 I added a new post about wicket gates that were added to the solid gates in the courtyard gateways.


To invite discussion of how courtyards can affect indoor and outdoor climate of houses, I opened a thread “Courtyards for Climate Control” on the forum of the Alternative Technology Association (ATA) based in Melbourne.

Louvre window for summer nights

Photo of an opened louvre window

The louvre opened

A daily chore in summer

My high-mass solar-passive house keeps me comfortable through the year with very little attention. I have detailed the actions I must take in this post. Being in BCA Climate Zone 4 “Hot dry summer, cool winter”, I have a summer regimen to keep the house cool, and a winter regimen to keep it warm. Most actions are required only twice a year: to change over from one regimen to the other. However, one action is required daily throughout the hot season: I must open doors each evening to admit cool air, then close them again in the morning. At night, air is drawn through the house and out the clearstory windows by the stack effect, assisted by fans at the windows. Warm air in the house is purged by the flow of cold night air, which continues to cool the mass of the house until sunrise.

My louvre vent project

[Photos, with descriptions, may be seen in carousel view here.]

Note.
Subsequently, I had to have the wooden louvre blades replaced with glass ones, as I describe in a later post.

Installation

I have put into effect a long-standing project to avoid the daily chore of opening and closing doors. I bought a motorized louvre window (Breezway Altair Powerlouvre Innoscreen) to let in the night air.

Photo of a programmable time clock

Louvre Time Clock

It is controlled by a programmable electric time clock (Hager EG203E) that will open the louvre at 21:00 and close it at 07:00 daily through the hot season. In the cold season the louvre will remain closed, with the motor control turned off.

 

 

The louvre closed

The louvre closed

The louvre is installed low in a wall on the colder south side of the house. It is near the back door that I have been opening and closing up to now. It was difficult to find a place to fit it.

I thought of fitting a motorized louvre in the back door itself. This would have been awkward and expensive. Doubly so, because the back door opens into the laundry, which forms an air-lock, and the inner laundry door would also have needed a motorized louvre.
The kitchen was the only suitable room to admit the cooling air. Of course, it is almost completely lined with benches and cupboards. Eventually, I found a place for the louvre, and had a hole cut in the wall for it.

Wall hole for a louvre

Louvre aperture from outdoors

Wall hole for louvre

Louvre aperture from indoors

 

 

 

 

 

The place I chose is partly behind the refrigerator. Continue reading

Constructing My Solar-passive House

Photo of tossing a brick

One Brick Thermal Mass

The “Indoor climate” posts on this blog relate to the particular house that I live in. Mainly by luck, it has proved to need very little energy indeed to remain comfortable in all seasons.
Recently, I have collected and arranged photos of the house so that people can see what kind of a house it is.
These photos are accessed by way of “My House Page”.

House footings on a rise

Footings View East

In the last few days I have uploaded photos of the stages in the building of the house. They are in two galleries. The first, “Building Photos: Start” covers from preparation for building up to the erection of timber frames. The photo on the left, showing some of the footings, is an example.

The second new gallery, “Building Photos: Finishing” covers from laying bricks for thermal mass walls (as in the photo at the top) to the completion of an acrylic textured coating on the walls.

Photos of the completed house, inside and out, had been posted already, in “Award photos 1999”.

Once an “Indoor Climate” post or page has been accessed on this web-site, links to all others appear. A post such as this one, when accessed through “Home” will not link to the others until it is selected positively by clicking its title line.