The Right Sunroom Size for the Right Plan

[ebass]

John, Glenn, Anyone?

   I've been thinking that if I bought one of John's plans, (Victoria's Cottage or 20'x30', 1 1/2) that another sunroom thought I had was that I might want to attach a sunroom and a deck to another part of the building.

  One of the "long" sides (this, in my own language means, not one of the gable ends) would be facing south... Somewhere near the center of that south-facing side, I'd like to have a small sunroom and a small deck, side by side......  my idea is to essentially to build half of what you see in John's sunroom drawing.....to "split" the design at the ridge line and attach half of it  to the side of whatever plan I decide to go with, likely with a 10' or 12'  sidewall.....

   The burning questions are.......what would I want the dimensions of this sunroom to be, if I want to have the benefit of also using it to generate some ammount of heat during cold times of the year?.... (for New England, usually 4 to 6 months)........ could I circulate the heat this room would generate into the house without using electrical devices?...........

   Any thoughts on these ideas, pro or con, will be appreciated as always..........

   ebass

[Daddymem]

See the skylights on John's Solar Saltbox sunroom?  Placement of those over windows in a manner that allows the low winter sun to shine through the sunroom and onto a thermal mass in the house will help a lot, and when that hot summer sun is beating down from a high angle, the rays shouldn't reach the house interior to avoid overheating.  With this methodology, the size of the sunroom can vary more.

[John Raabe]

The sunkit download or hardcopy http://www.countryplans.com/solarkit.htm is a good introduction to designing for solar and the trade offs of mass and glass. Much of this is climate and site determined and there is no one size fits all best solution.

Having said that, sunrooms will generally not pay for themselves in solar savings to the heating load. There are more cost effective uses of passive solar (sun tempering) than sunrooms.

[glenn kangiser]

Mother Earth News years ago had some convective solar collectors that went at an angle outside the window and collected and circulated heat on their own.  Here is an article that talks about the old one and shows you a newer design, giving you the principle of how it works.  Maybe a way to vary the solar you get.

http://www.motherearthnews.com/library/1982_November_December/Solar_Rise_Your_Apartment_with_a__75_High_Rise_Heat_Grabber_

[Shelley]

Gawd Glenn you must be as old as we.  Believe that was not the first article.  Think there was an even older one showing it simply leaning against a house wall.

Just a simple box with channels.  Don't know how you rig it up without double/single hung windows.  I always thought it was rather elegant....but got voted down on my experimentation.

[glenn kangiser]

Just guessing that I'm a little behind you - You seem more experienced than I am- but I try

A friend gave us several bushels of Mother Earth News and you're right - the one I was thinking of was the one you leaned on the side and dropped the window down on it.  I think I have most of the M.E.N. but the best way now is probably the searchable CD rom they have.  All the stuff clear back to when they weren't a sell out advertising rag- new owners gotta make a few bucks- they still occassionally come up with some fair stuff, but not like they used to.

[ebass]

Daddymen:

   So, to paraphrase your statement into my own words........you mean: winter sun shining through the glass roof of the sunroom,  into a second window, or some similar opening...... on the side of the house, but located within the confines of the sunroom........is this correct?..........

   I thought of constructing the entrance from the house to this sunroom with a set of double doors that would be close in dimensions to the height and width of the sunroom.........the problem then would be what to use as a thermal mass.........

   I saw a photo of John's with a pair of water tanks of some type, connected to pipes, located just below some roof panes.......that seemed like a good idea for something fixed in place..........as I've thought this out further.......with double doors, I'd need a thermal mass that could be placed in that doorway, something that was portable or at least movable........does such a thermal mass presently exist that would fit this need?......... is this making any sense to you?

[DavidLeBlanc]

My parents had a small sunroom on a S facing wall in the mountains in S. Colorado that pretty much heated the whole (small!) house on sunny winter days.

There was 4' of crushed rock under sand-laid brick, 72" tall double paned window units (in home-grown frames) and 3 skylights - the skylights had to be covered in summer!

In retrospect, the sand-laid brick floor was a bad idea and I believe they later cemented/grouted it. Otherwise, it was a PITA to keep clean.

The room was connected to the rest of the house by a double-wide door opening (with doors) and 2 regular sash windows that had once been on the building's exterior. There was no forced air movement and it would still keep the ground floor (5-600 sq. ft?) comfortable during the day. After dark, wood fired stoves carried the load and there was little "dwell" - you needed the fires as soon as the sun went down! The sunroom had an old pot bellied stove and the room was cool if it wasn't used, but not too cool to be uninhabitable.

[ebass]

 David:

    Do you remember the width of the sunroom?.......
Did the brick floor aid in heat retention?........
Having to cover the skylights in summer sounds right.....I'm trying to think up an easy way to do that.........Thanks for your posting.........it helps to hear this kind of info.......

  ebass  

[glenn kangiser]

Ebass, check this Trombe wall info out and see if any of it is interesting to you.  Had M.E.N. site open from  earlier and they had some info- have seen more in books- etc.  No fans.

http://www.motherearthnews.com/library/1979_January_February/The__Sunburst__Solar_Home

[ebass]

   Thank you, Glenn......... This has a humungous ammount of interest!.......

   ebass  

[DavidLeBlanc]

I'm thinking the sunroom was no more than 10' deep front to back. Maybe 12' at the outside. Maybe 24-30' long...

I'm sure the bricks did help some with heat retention, but like I said, the room did not have a lot of "dwell" - it cooled pretty rapidly once the sun went down (I have my suspicions about how well the roof was insulated though...). On the other hand, there was no effort at all to move warm air down into the 4' of crushed rock thermal mass and heat that up - was just reading a site that used warmed air during the day to heat the thermal mass in greenhouses and appearently it works well.

The skylights where only closed off in the summer (perhaps one reason why the room cooled so rapidly in the winter) and that was done by the simple means of appropriately sized white foam panels, not at all thick. They were held in place by bent nails... A good source of difuse bright light.

It was also important to pull the drapes once the sun went down. I think, but am not sure, that they were insulated.

[Shelley]

If you haven't already, read this article that Amanda posted earlier in another thread.  Excellent.


http://64.233.167.104/search?q=cache:EVRzETbSneEJ:www.homepower.com/files/featured/105_38_PassiveSolarBlunders.pdf+%22Home+Power%22+Dan+Chiras+Design&hl=en%20target=nw

[Shelley]

As far as the skylights.... www.zomeworks.com, located here, in business forever, think Steve Baer used to own it, sells a shade.

Or, you can fabricate your own from shade cloth, grommets, and some  hooks.  

Don't know where you are, but think carefully b4 you decide upon skylights.  They're holes in your roof compromising your insulation and they can overheat the space during summer.  If your climate is mild like John's, probably not so much an issue.  And if you installer a diffuser you can mitigate that somewhat.

[Daddymem]

Daddymen:

  So, to paraphrase your statement into my own words........you mean: winter sun shining through the glass roof of the sunroom,  into a second window, or some similar opening...... on the side of the house, but located within the confines of the sunroom........is this correct?..........

  I thought of constructing the entrance from the house to this sunroom with a set of double doors that would be close in dimensions to the height and width of the sunroom.........the problem then would be what to use as a thermal mass.........

  I saw a photo of John's with a pair of water tanks of some type, connected to pipes, located just below some roof panes.......that seemed like a good idea for something fixed in place..........as I've thought this out further.......with double doors, I'd need a thermal mass that could be placed in that doorway, something that was portable or at least movable........does such a thermal mass presently exist that would fit this need?......... is this making any sense to you?

Yeah, your statement is correct.  See this picture of John's? http://www.countryplans.com/images/passv.gif
Imagine that winter sun shining through the skylights in a roof of a sun room.  Now picture how that summer sun would just shine down into the sunroom and the mainhouse gets shaded by the sunroom.

Thermal mass can be a number of things.  There are tile floors, a brick fireplace, water tubes, any object that absorbs heat and gives it off slowly would be a good candidate for thermal mass. Here is a brief description: http://www.consumerenergycenter.org/homeandwork/homes/construction/solardesign/thermal.html
 Hope that helps.

[ebass]

Yeah, your statement is correct.  See this picture of John's? http://www.countryplans.com/images/passv.gif
Imagine that winter sun shining through the skylights in a roof of a sun room.  Now picture how that summer sun would just shine down into the sunroom and the mainhouse gets shaded by the sunroom.


Daddymem:

   I pretty much understand most everything so far, but there's one concept that leaves me mystified........how can a main house be "shaded" by a sunroom, even in summer?..........it seems to me that a room made up of  transparent glass on 3 sides along with the roof, will still allow the sun's rays to pass through and raise the temperature regardless of the angle of the sun.......... would you please explain why or how it would not?.........


Thank you,

ebass

[Daddymem]

Don't glass all the roof...leave an overhang to block the high summer rays but let in the low winter rays.

[glenn kangiser]

A south facing wall with glass having appropriate roof overhangs will not get summer sun due to the higher angle of the sun, but a glass roof without shutters of some sort will have to make heat as I see it.  Maybe I'm missing something. :-/

The sunroom could shade the front of the main house in the summer if the roof was solid and the sun couldn't hit the front glass due to it's angle.

[Daddymem]

Bingo

[ebass]

Hi Guys:

  I understand your words without a problem........
but is there something here conceptually that is getting lost?..........

when I think or write of a 'sunroom', I'm thinking of an actual 'room' attached by one wall to the side of a house, similar to a greenhouse, but for solar gain, not for plants.........

I get the impression that maybe you are thinking, at least in part, of a room 'within' a house, that has skylights and a glass south-facing wall....... both ideas are different, yet both might be successful in the right application.......

    If you could suggest books, magazines, websites, anything that has pictures of successful sunroom designs on small homes.......particularly in a New England type of climate......I'd be most appreciative........the idea of building is not just a passing phase for me........I'd really like to do this, and it would be a real 'headache' (feel free to substitute with the word of your choice here).....to get a quarter or half way into such a project, only to find out that either my house or sunroom designs include any of the "Ten Passive Solar Blunders" (thank you Shelley )......

I wonder if John could be approached to create a few good examples of sunrooms attached to any of his small house designs?........ Do you think so Glenn?

 Thank you to anyone who can offer examples......

 ebass  

[Daddymem]

I guess we just aren't hitting on what you call a sunroom.  Do you mean like this?  http://www.patioenc.com/residential/images/Gallery/Res46.jpg

I was thinking more like this: http://www.patioenc.com/residential/images/Gallery/Res25.jpg

No heat, little if any insulation.  My parents have a 12x12 similar to that, but instead of skylights they have ~2-feet of glass at the outside edge.  Unfortunately theirs was an addition and the house faces the wrong direction to gain passive solar advantages.  Their sunroom gets warm eary in the spring and stays warm late into the fall so it is basically what we call up here a three season room.  I hope to do something similar in our construction, also in New England.  

[ebass]

 Daddymem:

   Yes!.....The first picture, glass roof, is what I have in mind.......but only if it would be a successful structure to attach to a house for solar gain.....I'm not overly or emotionally attached to any one particular design.

 If I don't see any purpose or advantage in that one, or any other, I'm prepared to scrap the idea and go back to the drawing board........it has to justify itself to some 'reasonable' degree of energy savings for a small house, or I just don't need it.

The design of the sun room in the second picture would be an acceptable alternative, but I'd omit the skylights........a building inspector recently told me that eventually they all leak, and I think I
could live very nicely without the problems they bring......I used to know a good builder, and he even had leaks from a skylight in his own home.


Your parent's 2' of glass at the outside edge of theirs, sounds like a good compromise, providing the sunroom was placed in the right spot....

Diagrams, drawings and explainations of how to build attached sunrooms (or 3 season rooms?) that are closer in design and proportion to your pictures, or what I have in mind, or for anyone who is thinking or planning to build, would be very helpful......

It is really hard to nail down one idea on this.....it all seems so very vague at times......I need to know more about this......

Thanks so much for your input.....and please keep generating those ideas....

ebass

  

[Daddymem]

Ok, so now we are on the same page.   If you go with the all glass sunroom you could first extend the overhang of your house and attach the glass to that.  It would work just like the eaves on a house with regards to sun angle.  How much overhang you ask?  No straight answer for that but here is a start http://www.eere.energy.gov/consumerinfo/reading_resources/v101.html

Another option that may be more desireable is to have some form of shade attached at the roof against the house that allows you to manual adjust how much glass is blocked to prevent summer sun from entering and open up wide for winter sun to enter.  Of course the sun has to shine onto something with some thermal mass to it so heat is absorbed during the day and then dispersed slowly.  If for no other reason...the sunroom will act as a buffer to the cold if it is used as the entrance to the house.  It will always be warmer in the sunroom than outside.

[ebass]

Thanks for the website..........so,....... adjustable shade for the roof...... interesting.........based on your knowlegde and experience, would a white or light-colored, window-type shade, attached internally to the roof, just under the panes of glass do the job?.........

[Amanda_931]

The absolute simplest kind of "sun-room" for solar heating could have only a one or two square foot footprint.  the kind of "solar chimney" that sends heated air up, either into the building or outside.

Of course I have a book that recommends experimenting with this concept by hanging a black plastic bag in front of your south-facing  window--gaps for air movement top and bottom, sealed at the side would be good.