Wednesday, November 28, 2007

still testing

Well last night's tests weren't that successful, but I think that I have learned a few things.

1. synthetic fibers did not work so well.
2. mesh spacing is very important
3. a very thin skin of ice can keep the wind off.

the test panels that did work a little bit had some things in common, close spacing of the fibres. Water does not soak into these synthetics but it does get caught between fibres and held by its surface tension.

later today when it gets colder I will test out some natural fibers, cheese cloth, reinforced cheese cloth, muslin, and perhaps burlap.

I am watching the barometer (and thermometer ) closely here. If I could stay for an extra day or two I could hit an expected cold snap.

more as it develops

Carl

testing

I am in Kelowna today, flew up on westjet. I am doing tests in my friends' front yard here. The weather is supposed to get down to - 8 C tonight. If I were able to stay longer ther will be a colder snap coming through, but I only have so much time here.
These tests that I am doing are the ones where I am actually spraying water onto fabric/mesh in order to make an ice surface. So far the tests are not going too well. It may be that it is only about -2 C now, but I was hoping for a faster freezing time.
One thing that all these tests have in common is that they are using synthetic materials. I have five different meshes, all wetted at the same time, in the same place. Perhaps tomorrows tests should be all natural materials, should these tests tonight prove discouraging.

perhaps there will event be another post today...

Carl

Sunday, November 25, 2007

Big Long Post... but still no pictures.

still no pictures. my friend set up a blog on my website, but i really have no time to customize it right now. I will just go through flickr and post links to my flickr page.


on the topic of "where is my project at?"
I need to make a big presentation Dec 12th so everything is timed out backward from then.

here, in a long post, is how this design has evolved ...

Topics

Introduction
Geodesic
Large full system
Modular components
Net + Ice
Inflatable
Inflatable Geodesic Ice Mesh - proposed design direction



Introduction

well... i started wanting to build greenhouses for the arctic. Actually it started before that but greenhouses were my first direction to tackling the problems of health and diet which are found in the Canadian arctic. I found that greenhouse technology and materials were a fairly mature already. The reasons that this has not taken off in a large way are that heating and lighting are brutally expensive during the "out of season" times. Also, materials and transportation costs are very high. Also there seems to be an uncertain fuel/energy availability in some areas.

I have directed my project to address cost, weight, ease of setup in a product that provides a means to decrease costs arising from heating loss. I have identified heating loss from "forced convection" as a large factor for buildings in the arctic. Forced Convection is the process where (arctic cold) air moving over a surface causes heat to be exchanged ( lost ) a greater rate than if there were no wind movement. My project seeks to minimize this loss. The project also considers ways to collect sunlight from a large area, for use by a greenhouse, and being able to reduce the heating and lighting budgets by this method. The proposed design will also need to meet the demands of wind loading and snow loading.




Geodesic

During my research I have explored various methods of construction. Initially I examined geodesic structures in combination with aluminum frame and corrugated polycarbonate panels. Although this approach provided a flexible and reconfigurable structure, it was apparent that it would soon be too costly to actually be implemented. At this stage I had conceived that I would be building a style of greenhouse.

Large full system

After realizing my budget constraints I began examining build a development which included some greenhouse facilities, but which could serve other roles as well. At this time I was aware of three techniques in maintaining heat; doming, burying and nesting. I had researched materials enough to know that opaque materials could provide better insulation per dollar than transparent ones. If I designed a larger complex I could use a variety of materials and be able to implement doming, nesting and burying all in one, albeit complex, design. This could use a glass or polycarbonate roof with walls and floors built from high performance foams, with air breaks and a variety of other building techniques. I could effectively bury a nested structure with glass or clear roofs. Although this might work, perhaps even well, it had become too complicated, and the costs would make this sort of venture a major commitment for anyone financing it.

Modular Blocks

I continued on the idea of burying the structure, but rather than literally burying it I wanted the same effect. Burying removes the effects of wind. I wanted to shelter structures from wind. Animals take shelter from the wind. Seals, when pupping, will build a little mound to dig into for shelter. I wanted to create walls, not permiable to wind, yet which light could pass through. I thought that I could cast blocks in ice, with a mesh matrix for added strength, that would serve this task. There were many points where this seemed appealing; indigenous techniques, available materials, lots of cold to go around. This technique has much merit in that alone, but also allows for a control of the wind which hits a structure, possibly to be used for some benefit. This control could come from blocks which are formed to create a channel for wind to move in, rather than to just move over the surface. Although this approach seems to have a lot of merit the labour required to build a wind barrier might be too large for this approach to succeed.

Ice Nets

At this point I was also examining the idea that a fabric mesh be sprayed with a coating of water, which when frozen could act as a wind barrier, while still being thin and transparent enough to allow light to pass through it. Here I thought that I had found a way to quickly erect a barrier and make it solid, my worry was that this sort of structure would not be strong enough. This method would also demand a frame of some sort to support the final weight of the form.

Inflatable

After the most recent round of critiques I have investigated inflatable structures. This type of structure is well suited for a quick and easy deployment. Inflatables seem well able to support the type and size of structures required. Shipping weight, cost and adaptability to the best form are areas where the current inflatables designs may be improved.


Proposed Design...

My proposal will consist of the best of all these approaches. It will be lightweight, simple to assemble, provide a variety of different forms and configurations, it will be transparent and a barrier to wind.

A triangular panel formed by fabric edges which house inflatable structural members, the face of the panel will be a mesh of an inexpensive, durable and thin material (nylon) which will have a cell size small enough to allow a buildup of water on its surface, but still to be large enough to allow the passage of light. Panels will have a front and back face which will be separated by the inflation of the tubes. The air pocket created by this will allow a small measure of insulation. Panels will be joined at their edges by means of ropes passed through the grommet holes. The triangular shape of the panels will allow a great flexibility in the type of form which can be built. This could range from long wall type structures to domes, from rectilinear forms to highly organic shapes which are intimately adapted to their particular location. A weight saving will be gained over existing inflatable designs because the majority of the surface will be made of mesh (and later ice), rather than polyurethane coated fabric. Strong structures can be built because the edges where panels join can accommodate many panels in a branching, rhizomatic pattern, rather than a typical surface-shell type of structure. Any structure built and made strong with ice could be turned into a economical reflector if a survival blanket (aluminized polyester) were to be attached to it.

Tuesday, November 20, 2007

mesh or block

In a previous post I wondered whether to build a wind-shielding surface out of a mesh which gets sprayed down with water, or out of blocks. Each way has its benefits, but mesh would be easier to set up. and I think that is probably the clincher.

I am worried about the strength issues with water over mesh, and also how to ensure good clarity (want sunlight to get through)

2 weeks later...

I umm... guess i should update the blog more often.

I have a very specific direction now. To allow a greenhouse to operate later into the season, and to begin earlier by reducing heat loss from forced convection and by gathering light from a greater area (especially low angle light)

Forced convection is air moving rapidly over a surface, quickly taking all the heat from it. Its like when you blow on your hot soup, but if you had arctic wind as breath. It can be a large factor in costs.

I plan to gather light by reflecting it from a large cheap mirror. I plan to use aluminized polyester that has been set into a specially shaped solid transparent surface.

mesh or block?

Monday, November 5, 2007

Slow Day

Not much happened in project-land today. Catch up on other stuff from many days of neglect.
I found a book of this artist, Olafur Eliasson. He does amazing stuff. I want to do that kind of stuff, but maybe have it also be useful. Maybe one day.

http://www.olafureliasson.net/

-carl

Saturday, November 3, 2007

ice scuplture

Ice scuplture. no, really. But not so much like sculptures of pigs or carousels or the like. I'm thinking of ice as more of an engineered material.

I found this photo (i'd love to just post it, but this blogger software will NOT let me put a photo up.must. make. workaround)

its some frost on a chicken wire mesh and all the ice has been blown horizontally, awesome shot.
http://www.flickr.com/photos/54788032@N00/1141279468/

I am trying to address the operating costs of a greenhouse by creating a still air-pocket around it. I am thinking that cast ice components may be able to shape winds away from structures and toward generators. These may be viable structures for 8 months of the year in places.

Is it very windy where you are?
Is there anything done, structurally, to create windbreaks?

This might also be useful in places other than immediately around a greenhouse, like maybe in a common space. And there is a lot of opportunity for weird forms. Weird like cellular creatures and diatoms and pinecone-like things.

I had a sculpture teacher who taught a workshop to kids in Prince George, BC. Some mix-up in the planning stages had him arrive with absolutely no supplies, so he taught the kids how to cast ice into ice-molds (using a plastic bag in between). I am no expert, not nearly enough to teach anyone, and I don't know I could set this up but...

a challenge.
the highest temperature inside a structure, the most energy generated off of the surface, the least cost of materials and the best looking form.

I'd like to see that! I'd like to do that!