THE HOUSE AS A SIMPLE SYSTEM

A Viridian Project

The Virtual Strawbale House

Sunlight animation of site between 5:00 am and 9:00 pm on April 6 at Ottawa Click on image for rendering of Dec. 21 at noon

A current project is to build a virtual strawbale house with a masonry heater in it. We are looking for modelling software that can simulate the inside climate of the house. Any leads would be appreciated.

We would like to demonstrate that it is possible to build "The House as a Simple System".

Real world experience tells us that an efficient house can readily achieve high winter indoor comfort levels in the coldest climate without electricity or fossil fuels - similar comfort to advanced technologies such as the Canadian R-2000 house, but without the overly complex mechanical systems. In fact, no electro-mechanical components at all. With strawbale construction, it appears possible to build a dwelling with a minimum of embodied energy as well.

A key feature that we would like to demonstrate is thermostat setpoint relaxation that results when the Mean Radiant Temperature (M.R.T. - the average temperature of all the room surfaces) is increased by a radiant heating system. Strawbale walls would appear to make the ideal "high MRT" complementary surfaces to the vertical radiant panels (140 - 180 deg. F.) of a masonry heater.

A non-strawbale house demonstrating many features of this concept was designed 5 years ago by Allen-Kani Associates and built north of Toronto. "The Furnace Free House", (below) unoccupied, with no backup heating system, recorded a minimum indoor temperature of around 55 F during the coldest weather last year.

more photos

(Above) Main heating system for 1500 sq. ft. house near Ottawa Canada.
Wood heating chores: 10 - 15 minutes/day.

Low cost electric baseboard heaters as backup.

The Davenport House
Set among the wildflowers in a clearing in the woods is an energy efficient home. Inside the home, wood and ceramic tile help to create a warm and peaceful atmosphere. A massive masonry stove is the prominent feature in the great room.
Built by MHA members Gimme Shelter Construction

Here's another take:
The Furnace Free House? - questions from the solar frontier with Marc Rosenbaum and Amory Lovins

If you would like to get some hands on experience with modelling thermal mass, passive solar, etc., you'll find a treasure trove here:
http://arch.ced.berkeley.edu/vitalsigns/res/rps.html

For a wealth of strawbale construction information, visit the Surfin' Strawbale Links List, co-hosted on this server

The under-construction Autocad model of the house is shown in the sunlight animation at the top of the page. The oak tree to the south and the rendering were done with AccuRender.

To see a 15 frame sunlight animation for July 22, download simpsys.zip (500 Kb) and waaplay.zip (150 Kb) and unzip them. Use waaplay.exe to play simsys.flc. The animation at the top of this page is a 6 frame animated gif.

References:
1) Lovins, Amory, The Super-Efficient Passive Building Frontier, ASHRAE Journal, June 1995