Tag Archives: low-energy house

Louvre window for summer nights

Posted in Indoor Climate, Manilla NSW by
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

Posted in Indoor Climate, Manilla NSW by
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.

My Solar-passive House Photos and Details

Posted in Indoor Climate, Manilla NSW by

 

A plan of the house

Monash Street House Plan

Distant view from the south-east

Distant view from the south-east

Posts on “Indoor Climate” in this blog come from my experience living in my solar-passive house from 1999, and monitoring its performance.

Until now, I have not given readers a clear idea of what the house is like. I have now set up a special page called “My House Page” where details can be found. So far, there are two sub-pages, both referring to the time when the house was new:

  • A gallery of photos called “Award photos 1999”, and a house plan, which were submitted in an entry for the Housing Industry Association (NSW) awards for 1999.
  • An essay “House Profile 1999” that sets out the principles that I thought important then, and the features that I had built in to the house. I added a reading list of books available at that time, and a list of Credits to those people who built the house.

Navigation

The “My House Page” is not directly indexed in the main menu on the banner, but it appears with a hover over “Indoor Climate”.

Posts and Pages on Indoor Climate have links to each other in the side-bar on the right, in the panel “Indoor Climate Blog and Pages”. This panel does not appear on the Home Page, but only when an “Indoor Climate” blog post (or Category of posts) is selected.

I intend to add more pages in time.

Managing my low-energy house: II. Features needing attention

Posted in Australian Climate, Indoor Climate, Manilla NSW by
Photo of clear-story area with winter sun and a fan

Clear-story fan set for winter

This post, and the companion post “I. Features needing no attention“ were posted originally to a forum of the Alternative Technology Association (See Note below.)

My low-energy house at Manilla, NSW, maintains year-round comfort in a climate of daily and seasonal extremes. In the climate classification of the Building Code of Australia, it is in Zone 4: “Hot dry summer, cool winter”, along with Tamworth, Mildura and Kalgoorlie.
This house differs from most houses in relying on the design of the house to achieve comfort, with hardly any energy needed for heaters or coolers.
There is little artificial control: the “home automation system” consists only of timers set twice a year. Some of the comfort features call for daily action in certain seasons. However, these simple daily chores could have been avoided by small changes in the design. [But see “Note added 2016.”]

The success of the house in maintaining comfort in all seasons is shown by scatter-plots of daily indoor and outdoor maximum and minimum temperatures over a period of three years.

Features re-set twice a year

Dates for re-sets

For part of each year, the Manilla climate is too hot for comfort, and for the rest it is too cold. Some house features are re-set twice a year, making a “winter regimen” and a “summer regimen”. At first, I set the change-over dates near the equinoxes, 20th March and 22nd September. For simplicity I changed on 1st April and on 1st October. Later, I found it better to change on 1st March and 1st November, because the time when the climate is too hot is shorter than the time when it is too cold.

Motorized curtains

Curtains fitted to five north-facing windows, and a shutter fitted to a sun-porch window, should be opened to admit winter sun and closed at night to trap the heat. In summer they should be closed by day to keep out radiant heat and opened at night to allow heat to radiate out. The curtains and the shutter have motors controlled by a programmable timer (at lower right in the photo). In autumn (1st March), the timer is set to open at 07:40 and close at 17:20 daily. In spring (1st November) the timer is set to open at 18:00 and close at 06:00 (Standard Time).

Clear-story windows and fans

Continue reading →

Managing my low-energy house: I. Features needing no attention

Posted in Australian Climate, Indoor Climate, Manilla NSW by
Photo of sunlit house interior

July sun heats the house

This post, and the companion post “II. Features needing attention” were posted originally to a forum of the Alternative Technology Association (See Note below.)

My low-energy house at Manilla, NSW, maintains year-round comfort in a climate of daily and seasonal extremes. In the climate classification of the Building Code of Australia, it is in Zone 4: “Hot dry summer, cool winter”, along with Tamworth, Mildura and Kalgoorlie.
This house differs from most houses in relying on the design of the house to achieve comfort, with hardly any energy needed for heaters or coolers.
There is little artificial control: the “home automation system” consists only of timers set twice a year. Some of the comfort features call for daily action in certain seasons. However, these simple daily chores could have been avoided by small changes in the design. [See “Note added 2016” below.]

The success of the house in maintaining comfort in all seasons is shown by scatter-plots of daily indoor and outdoor maximum and minimum temperatures over a period of three years.

I. Features needing no attention

Heat transfer to and from the heat bank

The mass of concrete, bricks and rubble under the concrete floor slab is edge-insulated with foam to a depth of half a metre to prevent heat leaking sideways to and from the surrounding soil and subsoil. This 150 tonne edge-insulated under-floor mass is a “heat bank” which absorbs and yields heat so slowly that it holds the same temperature (at 750 mm depth) within a degree for weeks at a time.
Double-brick walls (17 tonnes) inside the house, and the floor slab itself (28 tonnes), are also parts of the heat bank. Their exposed surfaces (See photo.) absorb heat from sunshine (and yield heat to cool flows of air) so as to spread heat (or coolness) around the rooms. Within each day they conduct heat to and from the rooms of the house, and from room to room. They then conduct heat slowly to and from the under-floor mass.
In the absence of the house, the under-floor mass would have the same temperature as the subsoil of the area. A thermometer at 750 mm in the subsoil near the house shows a 14.6° yearly temperature range, from 12.9° to 27.5°. Even an ordinary light-weight, poorly-insulated house built on a concrete slab on the ground here would be made more comfortable by these stable subsoil temperatures. Midsummer and midwinter temperatures in such a house (next door) are plotted here and here.
It is clear that temperatures in that conventional house vary much less than outdoor temperatures, and remain close to that of the subsoil. The heat bank under my solar-passive house has an even more stable temperature than that of the surrounding subsoil. (There is a graph showing one year of heat bank and subsoil temperatures here.)

Insulation

Thermal insulation reduces the flow of heat in and out of the house. With sufficient insulation, the heat of the day is replaced by the cool of night before the house becomes too warm. Insulation improves comfort permanently. Continue reading →