The sunroom
 

Below is my sunroom. Its a fairly good sized room at 32x12' and I am dearly hoping it will help heat the house a good extent this comming winter. ATM it looks as it does below. I'm looking for some tips on how to make it a more efficient heat source. The blinds are a kind of double air pocket type so they do have some insulation value and I have been putting them down at night now that its cooling off. I know it really needs more thermal mass added to it and that'll happen when my cousin moves in. However, I am wondering what other people have used to add thermal mass to their rooms? What have you found that works good for spreading heat from room to room?



http://www.tercelreference.com/downloads/house056.jpg

http://www.tercelreference.com/downloads/House034.jpg

I'm not sure I have any real good advice for you but from a thermal studies point of view, air tends to only lose its convective properties when the trapped air mass is at a maximum of 2 mm in width between the solid surfaces. Then it has only a purely conductive component to its heat transfer. This is obviously a gross generalization but it holds true mostly. I guess my point is, the blinds won't help or hurt you.


if you are serious about using the room for heat I wonder if you could get a covering that would alter the light color but reduce the radiative heat leaving the window. There are a ton of ways to have a covering that has great absorptivity and low emissivity. Does a solution like this exist?

I use my poorly insulated front porch to a similar extent. It's a ~10'x15' room. With a decent door (might have to change it more to an 'exterior' door at some point) and new double pane with argon gas, blah blah blah window between it any my living room (see below for living room side pic) The room gets the sun a good portion of the day, so during early winter, it stays closed up, and when i get home from work, I'll open the front door, and let the heat seep into the living room. It'll usually raise the temp a few degrees. I never really thought about how to make it HOTTER in there.

During the summer, this room stays sealed up, except that I'll leave the windows open, so it's only as hot as the air outside, no hotter (well kinda).

http://img.photobucket.com/albums/v5...e/d22082a4.jpg

nice half stack.

the house I grew up in had a sunporch that my parents used for storage. I just remember it being super hot in the summer and super cold in the winter because it had no insulatin in the walls.

Is the one attached to your house insulated? If it keeps the cold out I think this could be a pretty efficent way to add some heat.

hey doax...Which side of the house is the sunporch on? looks like its at a nice angle to add some solar panels if it gets enough sunlight.

The sunroom is on the south side of the house. Solar panels may be possible there, but there is a gigantic tree right on the left side of the outside picture that blocks at lot of sun. Great for the summer and winter passive solar, but bad for solar panels.

Definately check to see what you have for insulation in the walls and roof of the sunroom. Also, are they good, tight, modern windows, or old drafty ones?

What is the sunroom over? Is it over basement, crawlspace, or concrete slab? This will effect how it heats.


Your cousin adds thermal mass? How much does he weigh!?!?!?


A relative of mine has an old house with a "sunroom" on it which was originally a front porch. It is poorly insulated, and has nothing under it. They just close it off completely in the winter because it would otherwise suck heat from the house.


Could you see a woodstove in your future? Not sure how close to town you are, but a stove in the south-east corner of the sunroom would put the chimney on the prevailing downwind side of your house.

If the sunroom is on a concrete slab, run a wood stove continuously for about 3 days, on the 4th day your floor will be totally warm all day whether you run the stove or not. It's a neat feeling.

The sunroom is probably the newest part of the entire house. It has been added on within the last 10 years. It is 2x6 construction with standard fiberglass insulation and polystyrene (not sure on the thickness) on the outside. It has blown in cellulose insulation above it, and a insulated floor with an unaccessable crawlspace under it. It has with hydronic in floor heating.

My cousin will add thermal mass to that room in the form of their furniture and other things. :p I just want to come up with a way to get more thermal mass into the room without making it painfully obvious.

Ideally, I'd love to take out a basement wall to add a access to the sunroom. I would fill the crawlspace with jugs of water and insulate it if need be. Then, I would add vents and circulate the air from the sunroom through the crawlspace to add lots of thermal mass.

would the jugs of water be the "thermal mass" you are referencing? Never heard of that before, that's why I ask.
How difficult would it be to take out a basement wall to access that area?

Yep, water is a great way of storing heat as it can store a lot of heat per volume. See the wiki here for info on thermal mass.

I'm guessing it would be a pretty large pain in the butt to cut an access hole into the crawlspace. My basement walls are probably 1.5-2 feet thick and is a fieldstone basement (stone + mortar). I believe I'd need a jackhammer to get through the wall. If anyone has any ideas I'm all ears.

Is your cousin going to live in the sunroom?
If not, can you close the door to the sunroom? Simply open it during the day to heat the house and close it at night so the house doesn't lose heat through all those windows.
Assuming you have other radiators through out the house for your hydronic heating system, you could use the warm floor in the sun room as a heat source, and not use your "real" heating source. Just let the circulator pump run and it will help balance the house temperature during the day, and remove the sunroom from the system at night. You'll sort of have a really expensive solar hot water heater that is also a sunroom :D
Ian

Daox: You can do fun things with color. Reds absorb the least thermal gain (that's why it's red); greens, blues, grays, and of course black are best. It's a nasty job, but you might consider changing the reddish floor tiles to a more thermal color. You could use the opportunity to lay down a radiant barrier underneath. Likewise the back wall, if the sun gets low in winter.

Cellular blinds have an R value of around R-2 or 3. Not great -- but uninsulated glass is around R-1, so it still helps. We have single-cell blinds on sloped glazing, and it's a terrible thing if we forget to close them at night! Some (expensive) blinds have a silvered lining, which can be hugely effective at stopping re-emission of heat. Coated windows likewise. But for a cheap solution, stitch up some winter drapes: a nice heavy fabric on the inside, a layer of silver bubble foam, and some polyester ticking on the window side. In conjunction with your cellular shades, they will reduce losses by convection and radiation.

Ah, radiation. It moves in straight lines and abhors partitions or hallways. My house is designed spoke-wise in an attempt to get the passive solar into each room, but older homes aren't usually that open. Your big double doors should carry heat into the house fairly well, though transom windows and vents near the floor set up a nice convection loop. You could go for some tromb wall thing, but I'd rather use free-standing solar hot water panels and active solar. Or put some black or blue 55 gallon drums of water in the sunroom in winter.:D

Nice-looking house!

Thanks for the tips on the blinds Bob. I'll have to look into it a bit further. I haven't taken the time to do anything with the sunroom yet.

The book: 'Design for a limited planet' should be a must for you here.

I doubt you would ever regret finding a copy, but rather it is a real treasure of information.

A hot tub or indoor fish pond could be your heat storage? You could pump its water under your bedroom or living area... And collect heat via a long bench seat below the windows along the long wall...filled with drums of water??

Ideally taken to extreme... modify the whole wall/glazing/eveoverhang/colour relationship...summertime opening right up to a courtyard or paved area would be nice

A blower fan ducting warm air from near the ceiling to other parts of the home, would also capitalize on potentially wasted heat thru the lean to roof

The heavy drapes idea is a great way to help keep the heat from escaping. This winter I put blankets up over large windows and the patio door that had only blinds before. It seems to be making quite a difference. This winter has had alote more heating degree days than last year, 4671 vs. 3989 so far. We have used a few % less propane, and a couple face cords less wood.

You could add some skylights for more direct gain, but you'd need to make insulated panels that close them off when the sun isn't out.

Our sunroom is very similar--about 14 by 24 feet on the south side of a hundred year old farmhouse. We have more glass on the south wall, and more roof overhang. Our south glass is shaded much of the summer so it doesn't overheat much, and is usable all summer. In the winter we have insulated homemade shades or curtains the cover much of the glass, and with almost no added heat it stays above freezing even if it is 30 below outside. We have a number of black 15 gallon plastic drums in the room for heat storage, but don't really know how much good they do.

Ooooh, plastic drums, I like that.

Actually, my cousin's family is moving out this weekend, so I will be reclaiming the space. This winter it'll hopefully be turned into a full blown heat source. I really want to add as much thermal mass as I can do the room and plastic drums are an idea (one that the wife doesn't love, but would accept if I could do it and make it not look bad). The next idea is adding lots of plants to the room. The dirt and water in them should hold heat to some extent. Additional ideas are quite welcome!

This sounds like a great candidate for a solar-thermal radiant floor set-up to me. Wish my "sunporch" was starting out this functional (facing east, non-functioning windows, uninsulated slab floor, prob no ceiling insulation):(.
That hydronic radiant floor system is begging to be linked up to a DIY panel or two on the roof (like the "Build-It-Solar" ones...). Part of the plumbing job is already done. Maybe trimming that tree would let you put one on the east end of the sunroom roof?

As far as thermal mass:
I'm not clear why you'd want to put it outside the insulated space (below the floor). ?
It isn't really a passive-solar designed room, so: Unless the room gets uncomfortably hot during the day in the heating season, with the house door open, or you want to use the room at night without heating it, why add thermal mass? You could just circulate the heat into the house during the day & close it off at night. Would it really stay warm enough to add heat to the house at night even with loads of mass?

The extra thermal mass wouldn't be outside the insulated space. It would be in the room somewhere.

I'm not sure how much heat it brings in during winter, but its a fair amount. That is by far the warmest room in the house if the blinds are kept open.

Now I'm really jealous. My little sunroom (7.5x12) is seriously cold in winter & too hot in summer. I do have plans for insulation, windows & doors, but I don't think I'll ever get much heat from it do to poor orientation.

hey Daox, have you thought about maybe putting in a layer of decorative brick wall as a heat sink? If you hunt around in the free ads you can sometimes find reclaimed bricks for dirt cheap or even free if you remove them yourself.

as for the tree in your solar path, hack it down and plant a few more else wheres if you're concience is bothering you ;)

That is really not a bad idea at all cdig. I'll definitely have to think about it.

However, the big tree will need to stay. It blocks a ton of direct sunlight in the summer months and really helps keep the house cool. During winter, the sunroom does get a lot of direct light since the trees have no leaves on them.

Hi,
Nice sunroom!

One thought would be to distribute excess heat from the sunroom to the rest of the house. This keeps the sunroom itself from overheating, and provides some heat for the rest of the house.

If there is an accessible attic, maybe a vent in the sunroom ceiling ducted to a ceiling vent somewhere else in the house, with an inline Fantech type fan, and controlled by one of those replacement thermostats for attic vent fans (HD carries these).

Low mass sunrooms can be good home heaters:
PolySpace

Gary

I second the brick-as-thermal-mass idea. It's a great way to add cheap/free thermal mass.

If you live in an area with alot of rock in the ground, DIG THOSE BABIES UP! Dig yourself a hole in the backyard, sift the rock from it, and stack them up against the wall (if you like stacked stone look). The hole in your yard that will be left over could also be utilized for other things, like a summer fish pond or a compost ditch.

You can do some nice designs with brick/cement/cinder block/stacked stone that look great and make excellent thermal mass. If you can make reflective frames to put around the windows, they'll pick up more sunlight as well. (Like the open flaps of a solar oven.)

Here's an idea I have had, and it actually ties in with a project Daox is working on/has mostly completed...
Temperature dependent door/shade opening and closing. If it's warmer between the glass and shade, the shade opens (in the winter), then when the room gets warm enough the doors open, automatically! Opposite for when the room starts to cool down. You can get a summer setting and a winter setting. You would also want it easy to temporally disable in case you wanted the doors open late at night for some reason. You may even be able to do all of this with one controller. I don't know much about the programming, but your Arduino actuated grill block would be perfect if you could figure it out.

Well, we got some area rugs for the sunroom. These should hopefully help increase solar gains somewhat.

The first one is a smaller rug. In the picture its hard to tell, but its a real dark brown color. Annie seems to like it.

http://ecorenovator.org/pictures/house312.JPG




The second one is much bigger, and multi colored. Again, browns and greens though.

http://ecorenovator.org/pictures/house313.JPG

Have you considered either a darker colored floor, or a floor with some thermal mass to it? Like wood or stone... Or even stove brick, might look pretty neat on the floor. What about a cobble stone floor? (Bricks) I'm thinking about a cobblestone floor for the area closest to the windows in my house, since there are only windows on the south face of it.

The floor actually is pretty hefty on the thermal mass side already. It is ceramic tile over the hydronic pex line with a sand trough sleeper underneath it.

Woops! The white-ish tile looks like Linoleum... I'm still thinking about doing a partial cobblestone floor in my house, though. It just seems to me like it would look neat.. and besides, if I don't like it, I'll just pull it back up, use the brick for something else, and do another type of floor, like wood scraps or something.

That sounds like it would be pretty cool to me. Lots of work though.

Oh, it's lots of work, sure... but it's so much better when you can sit back, enjoy your work, and think to yourself: "I did that."

Do you not agree?

Oh, definitly. My cousin recently did a tiled entry way in his house. He cut the tile to kind of swerve like a small stream, and then put in broken slate pieces. He broke the slate himself and had to sort through the pieces. It took him forever to get done, but it really does look great.

I bet that looks sweet...

With your Cousin's permission, I'd like to see a picture of it.

Ok. Your sun room heat rises. Put Pex tubing on the ceiling. Maybe a couple runs with the crown molding to hide it. Run fluid threw it. Collect the heat and transfer it to another part of the house or store it.

Get several barrels put plywood on the barrels. Table like. Fabric stapled around three sides to hide the barrels. no fabric between sun and barrel. Heat sink

Grow hydroponic lettuce, salad greens and cold weather vegetables, on top of the barrels. Most salad greens sell for $5-$6 dollars a pound in my area.

Flat white reflects light. Flat black adsorbs.

Make sure that ceilling is well insulated.



AcrylicStormWindow

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Building An "Interior Storm Window" To Reduce Draftiness

Interior storm windows NEED to be done to this room. The windows are nice thermal panes, but once the sun goes down it does cool down fast in the room still. It would be great to have interior storm windows along with some form of insulating shade/curtain.

A couple of black barrels full of water might do quite a bit of heating.

It would be interesting to have one with a thermometer on it and check it at various times of the day and night.

I have a 30 gallon black food grade barrel with matching O-Ring lid if you want to try it.

I do also like the idea of some solar hot water panels on the roof there.
I have heard of people with similar roof lines arranging hot water or PV panels so that any light that bounces off them gets reflected right into that second-story window. That way you get your solar collection AND some additional direct gain.

In an architectual presentation I watched a few years ago, the speaker pointed out in a photograph of how specifically WHITE gravel was used outside a building so that it would reflect indirect light into the building for an airy feel.

I do have some of those 2'x2' plastic mirrors. I wonder what kind of difference it would make to set a few of those on the roof of the sunroom to reflect additional light into the upstairs windows. I know snow accumulation would be a problem, but even snow works as a reflector as well.

Last I checked, my cousin still had those solar hot water panels to rehab. We should play around with one of those in your sunroom.

Yeah, I'd love to get some hot water panels up there.

Bringing back an old one. Ever do anything else to your sunroom to help retain heat?

Has the room help in heating your house?

No, I really haven't. I do manage the honeycomb blinds fairly methodically. There can be some pretty good heat gain from all the windows. On a sunny day its always warmer in there.

I still really want to do the interior storms. They just have to be remade at a different size to fit the window opening, and I'm buried in other projects at the moment.