There seems to be some confusion on what a Trombe wall is. This post is to briefly explain that. A trombe wall is a south facing wall which is made of a certain material that will absorbe a lot of heat energy. During the day this energy is collected then it is released at night, moderating the room/house temperature.
My previous post indicated two things. One making this wall out of water, and two creating the mass as the ceiling. Water has a very high volumetric heat capacity which means it can retain more heat for a longer period. In the image below you can see how the winter sun sits lower in the sky and allows for heat transfer to the wall while as in the summer the window has a sun shade blocking heat transfer to the wall to keep the house cool.
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| http://www.eere.energy.gov/de/passive_solar_design.html |
My idea was to transfer this trombe wall to the roof and in doing so it would retain the view from the windows as well as having the same effect as the wall. The main issue would be the summer sun. How could you block out the heat? I suppose having fans to circulate the room but also having fans to blow air out of the ceiling space could work. If you look two posts ago, I posted pictures of the house and you can see that the front of the house has a pitched roof in the southern direction unlike the picture above. Therefore if you could utilize that space for passive solar you could create quite an efficient design.
What about having some sort of electronic shutter system? You could have to so that during the summer they are shut, blocking off the sunlight, and during the winter open, allowing it through. However, I imagine you would get snow stuck in them. The shutters would also have to be very shiny to reflect as much heat as possible.
ReplyDeleteThat is quite possible, to ignore the snow you could put the shutters on the inside of the glass. I will post some concept ideas of what these would look like in a section. Thanks!
DeleteHere's a PDF on the ins and outs of trombe walls.
ReplyDeletehttp://www.nrel.gov/docs/fy04osti/36277.pdf
That has some pretty handy information. Thanks Matt!
Deleteanouther technology that i've seen used for a hospital in vanderhoof is solar walls. this is basically a perforated metal shell on a south facing wall this absorbs heat and is used to preheat the incoming outside air. This made a measurable dent in energy consumption for the hospital. This way the air captures the heat from the solar wall and brings it inside but in the summer you can bypass the solar wall and keep the heat out.
ReplyDeletehttp://www.monstercommercial.com/wp-content/uploads/2012/08/SolarWallHVAC_Diagram.gif
I received an comment via email. I figured I would post it on here as this is for school marks! It was from Brian Frank. They were having trouble commenting with an Iphone so they decided to email me the comment.
ReplyDeleteWould there be a certain number of sunny days needed for a building design like this to be viable ?
Could it work in reverse as well ? Maybe use a reflective solar blanket on top as well as one on the bottom - the top one could reflect heat away during the day in summer while absorbing heat from the house during the day (acting like air conditioning). Then in the evening retract the upper blanket and draw a reflective blanket on the bottom to maintain house temperature and radiate heat upwards that had accumulated during the day and repeat the cycle throughout the summer season .
Im not too sure how many days you would actually require to make passive solar design viable. What I do know is Kamloops is one of the sunniest places in BC. I believe we receive over 2000 hours of sunshine every year.
Deletehttp://www.tourismkamloops.com/weather-and-climate-in-kamloops-british-columbia
Using the thermal mass in the opposite order is definitely an interesting idea. Naturally if the interior blanket has a high enough R value the heat would radiate back out the window to the exterior. I will try and design something that would let me test this on top of comparing water and concrete for their thermal mass.