iDRY Vacuum Kilns

Sponsors:

Passive Solar Build

Started by Stephen1, December 04, 2019, 12:36:45 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Stephen1

I am planning on building in the spring. I have a great south by southwest building spot. Some big trees to the west and up on hill overlooking the lake. 
I want to incororate passive solar in the building.
Who has done it?
What did you do?
Thanks in advance 
Stephen
IDRY Vacum Kiln, LT40HDWide, BMS250 sharpener/setter 742b Bobcat, TCM forklift, Sthil 026,038, 461. 1952 TEA Fergusan Tractor

beav

Yes! Great idea!!
I built my house just before the turn of the century. It is a simple saltbox design with the tall side facing due south, the long roof side north. Every stick came off the mizer,  hemlock framing and pine sheathing.
The Windows on the south side allow the winter sun in, in the summer not much at all when the sun is high.
I also have off grid solar electric power and solar hot water.
I would recommend it for you!!
I have saved many dollars on heat. On a sunny day the stove can go out but it stays warm no matter how cold out

Hilltop366

The (Living room) gable end of my house with 3 fairly large windows is facing south plus a glass doors to the east and another window to the west so we get lots of solar gain when there is sun. The other side of the coin is at night when it is cold out you can feel the cold dropping off the glass. I'm thinking there probably is a overall gain but never really sure.

I find it is nice to have some east glass to get some warming first thing in the morning too.

One thing I did in my house is make sure that the dinning room in not on the west, after being in several houses with the dinning room on the west and when you sit down for supper you either have to put heavy sun blocking blinds which also blocks the view or suffer in the heat and have the sun in your eyes.

I keep saying that if I built another house I would design it so I would be able to do any maintenance from a 6 foot step ladder. 


Don P

I did the first drawing of our house in HS architectural drafting class. I kept playing with it as we amassed our nest egg and looked for the place. During that time I modeled it and set the model out at various times of the year to check the overhangs and sun angles. We have nighttime cellular blinds but I don't think we've used them a dozen times in 30 years. I took a class one time "Solar Energy for Homes" and one thing that stuck with me was "Passive Solar requires active occupants" Since we don't do things like pulling the blinds and trapping all the sun, there are now Persian rugs on the dark tile southern floor (not by my choice but a guy knows when to say yes dear). I never hooked up solar water to that slab so I call it solar tempered rather than passive solar. Especially in winter I need all the sun I can get so am quite happy with it.

For glass I ordered the low E coating on south and east pulling in heat and reflecting it back in, on the west it is rejecting the heat, yup dining is west and I don't like it. The original huge deciduous maple I planned on shading the SSW glass in summer has died and been removed, a new one is up but smaller, it is really my hangout on the deck more than a strict need of the house but think about that if you use the landscape as part of the plan. As a kid Dad used a white oak for that purpose, we were farther south, when it died we cooked as it was a southern gable of glass that overhangs couldn't shade. That is why I put the eaves on N&S on ours, gables E&W. In your climate not sure, we are warmer. A cardinal N wall doesn't get sun sterilization, we are kicked west of south a little, maybe 10°, the mountain blocks early E so that drove that decision. I've opened up the N this past year and that will probably help with that wall airflow wise but at the cost of more wind in winter.

Stephen1

It seems like the dining room should go in the middle!
Now the solar. A ranch style, long on the east-west axis. My bedroom will be in the south-east corner as I really like waking up to morning Sunshine! 
Can I just do a wall of 6-8' patio doors? A nice porch along the front with a roof overhang that will block the summer sun and let in the other 3 seasons of sun. 
I have a log home builder trying to sell me a kit, telling me do not put to much into the passive solar. I think in the dead of winter passive solar will not be a plus, but it is the shoulder seasons where I will see the gains His worry is that logs are more expensive than a stick frame, and glass is more expensive than logs = a log buiding out of my budget.
I like Don P comment of doing a TF ceiling. It will be in the great room/kitchen. I am leaning towards a stick frame as I like the cost of a SF build.  2x6 are going under $5 each, I would have troubles sawing, planing, and grading to = that.
I can use my own lumber to make flooring, panelling, and fake log siding to match my log cabin. 
 Still thinking and using the FF as my sounding board!
IDRY Vacum Kiln, LT40HDWide, BMS250 sharpener/setter 742b Bobcat, TCM forklift, Sthil 026,038, 461. 1952 TEA Fergusan Tractor

Don P

Our codes have minimum wall bracing requirements, that can be mind bending. I'm sure yours have something similar but you need to find and study those. FWIW here's ours, start at R 602.10
https://codes.iccsafe.org/content/VRC2015/chapter-6-wall-construction
Generally a minimum of a 2' wide braced panel at the ends or within 10' of the end of the wall the same or better along the wall according to its length but braced panels not more than 20' apart. APA has some good publications on compliance.

If you cannot develop sufficient bracing, usually its a wall of windows, then an engineer needs to design a moment resisting frame. Simpson has some narrow off the shelf solutions. After that it usually goes to rigid steel post and beam assemblies.

Bear with me for a rant against the machine ::). A friend was asked to bid a house and came to me for help, and he was going to need our Lull to pluck steel. The owner had drawn up a plan she liked and handed it to an architect to draw plans. Who then handed it off to an engineer for design of steel moment frames. I looked at the plans and said this is nuts, if she would just give up a window here and there in the walls of windows and replace those spaces with a bracing panel all the craziness would disappear. He bid the job and blew it out of their budget. He then suggested what I had said and it went back to the architect and has been redrawn and rebid. I've been through rounds of similar recently. They could have done a little bit of education at the front end and saved the client gobs of design fees.  That is why I'm saying research and know your stuff going in.

Stephen1

DonP I see what you mean. As always a little knowledge ahead of time can save a lot later. 
I was reading through your code and realized ours is very similar. I may not have a wall of glass, but i can see having patio doors along the south and west walls. the dining room is in the center, so in the morning I will have the sun which I like.
I have been talking to new inovative builders in my area. One does straw homes. The straw is compressed into packs.
One is well suited to my area of uneven rock, she drills the rock and inserts steel posts and ten angle iron joins the posts, then the frame of the house is built at a truss factory, the trusses rest on the steel. the truss is 1 peice in that they are the floor -wall-and roof.   A complete envelope.
IDRY Vacum Kiln, LT40HDWide, BMS250 sharpener/setter 742b Bobcat, TCM forklift, Sthil 026,038, 461. 1952 TEA Fergusan Tractor

beav

Stephen
In "The passive solar energy book" Edward Mazria recommends between 0.19 and 0.38 square  feet of south facing glass for each one square foot of floor area. Being your northern location you prolly wanna be on the upper level. Too much glazing on the south leads to overheating. West and East facing glazing also causes overheating, esp in the summer. We are close to the winter solstice now, observe how much sun would hit an East or west facing window now. Almost none.
If I was to do it again I would build two 2x4 walls staggered with carefully applied fiberglass insulation. No thermal bridging.

Stephen1

Quote from: beav on December 08, 2019, 05:12:03 PM
Stephen
In "The passive solar energy book" Edward Mazria recommends between 0.19 and 0.38 square  feet of south facing glass for each one square foot of floor area. Being your northern location you prolly wanna be on the upper level. Too much glazing on the south leads to overheating. West and East facing glazing also causes overheating, esp in the summer. We are close to the winter solstice now, observe how much sun would hit an East or west facing window now. Almost none.
If I was to do it again I would build two 2x4 walls staggered with carefully applied fiberglass insulation. No thermal bridging.
Thats an interesting concept, your wall is 7" thick?
IDRY Vacum Kiln, LT40HDWide, BMS250 sharpener/setter 742b Bobcat, TCM forklift, Sthil 026,038, 461. 1952 TEA Fergusan Tractor

beav

Actually my walls are a full 6". I cut all the wall studs on my mill. If I was to do it over again I would do it as above with the staggered studs. Hence no thermal bridging.

Stephen1

I would be using lumber store lumber for the framing. to many rule around here to use my lumber off the mill for structure.
IDRY Vacum Kiln, LT40HDWide, BMS250 sharpener/setter 742b Bobcat, TCM forklift, Sthil 026,038, 461. 1952 TEA Fergusan Tractor

beav

Ya i built mine in the good ole days before stinkin' code junk
You can however do the staggered stud wall with store bought junk

Don P

Quote from: Stephen1 on December 08, 2019, 09:01:38 AM
One is well suited to my area of uneven rock, she drills the rock and inserts steel posts and ten angle iron joins the posts, then the frame of the house is built at a truss factory, the trusses rest on the steel. the truss is 1 peice in that they are the floor -wall-and roof.   A complete envelope.
Interesting, that was experimented with when modern trusses and nail plates were coming on line. It never really took off mainly because of transport difficulty vs building components but there are savings if it can be hauled reasonably. I remember reading through the case studies and didn't think the juice was worth the squeeze after fireblocking etc was detailed in later but that part is up to their numbers.

Stephen1

Quote from: Don P on December 08, 2019, 11:00:24 PM
Quote from: Stephen1 on December 08, 2019, 09:01:38 AM
One is well suited to my area of uneven rock, she drills the rock and inserts steel posts and ten angle iron joins the posts, then the frame of the house is built at a truss factory, the trusses rest on the steel. the truss is 1 peice in that they are the floor -wall-and roof.   A complete envelope.
Interesting, that was experimented with when modern trusses and nail plates were coming on line. It never really took off mainly because of transport difficulty vs building components but there are savings if it can be hauled reasonably. I remember reading through the case studies and didn't think the juice was worth the squeeze after fireblocking etc was detailed in later but that part is up to their numbers.


One of the things that are they are able to do is build in the winter. They ae using laid off skilled trades, winter is a slow to non existant time to build here. No concrete is necessary, trusses are built inside,  so the winter becomes less expensive to build, also more tradespeople are available to build the lower cost buildings using this system. The trades people go back to the multi million $ builds once winter is gone. A better use of the limited trades people in this area.
IDRY Vacum Kiln, LT40HDWide, BMS250 sharpener/setter 742b Bobcat, TCM forklift, Sthil 026,038, 461. 1952 TEA Fergusan Tractor

alan gage

I somewhat incorporated passive solar into the house I built. I wanted to get some benefit from the sun but also didn't want to get too carried away with it financially. It was a relatively small house (1000 sq ft) and would be very well insulated (10" double stud walls) and heated with wood so while the solar gain would be nice it wasn't going to save me a ton of money.

I knew I wanted a large bank of windows to the south anyway so all I did was design enough overhang to block the sun during the warmer months and specify what coating I wanted from the window manufacturer. There are a multitude of different coatings but here in the US the standard Low-E coating blocks solar gain. There is another coating, which I believe is more common in Canada, that permits solar energy but still has a good u-factor for holding heat in the house. That's what I wanted on those windows. I had a bit of a go around with the window manufacturer and they tried really hard to talk me out of it. I finally got a hold of the right person and they said no problem. I expected to pay extra but it was the same price. The living room windows, which faced south and east, were the only ones with the "odd" coating. The rest of the them in the house were all the standard Low-E offered around here.

Pretty much all the window coatings come from Cardinal. You can look on their website to see the different coatings that are offered. I believe the window manufacturer's order the glass, pre-coated, from Cardinal and then install it in their frames. So if the manufacturer gets their coatings from Cardinal they should be able to supply any of the coatings offered (even though it won't be in the manufacturer's catalog).

It worked out well. I can't quantify how much heat I gained through those south facing windows but there were many days during the shoulder season where I didn't have to run the wood stove during the day and even in the middle of winter the gain was noticeable. If I'd been paying to heat with natural gas or propane it probably wouldn't have been a very big savings but doing it the way I did didn't cost me any extra money either; only some extra time figuring out the overhangs and window coatings. It certainly was a nice place to sit and read with the sun shining it. I had a concrete floor to absorb and retain some of the heat.

You mentioned a large bank of patio doors and the one thing I'd be worried about with that would be air leakage, which could easily more than negate any solar gain.

I think my south facing bank of windows was about 9' wide by 5' tall. There was one large 5' wide solid pane window flanked by two narrower double hungs.

Alan
Timberking B-16, a few chainsaws from small to large, and a Bobcat 873 Skidloader.

Klunker

For me passive solar is a no go until you insulate and keep air infiltration down as much as possible.

Worry about these 2 first.

My house is insulated very well is relatively air tight and it has the most windows on the south side by design.
I do gain heat in the winter on a sunny day but I don't have any way of retaining the suns heat.

There are periods of cloudy days that may last for over a week easily in the winter.

I can get power from a PV system on those days but no passive solar benefit.





Don P

The 3 I's, in order;
Infiltration , if you don't take care of this one nothing else matters
Insulation, you gotta have a blanket to keep it in. A window is generally R2
Insolation, if you take care of the first 2 then think about this.

The coating I'm familiar with is lowE, in the south it is often referred to as "heat mirror", it is on the middle face of the inside pane and rejects IR. So well it can blister shingles, melt facing vinyl siding and burn people sitting by hotel pools. I've registered a 60°F difference on blistered shingles compared to shingles right beside them but out of the windows reflection, the stuff works.
For solar gain the same coating is on the middle face of the exterior pane, IR and visible light pass in and any IR trying to escape is reflected back in. So it's just a matter of specifying which face the coating is on... and then keeping track of who goes where on the job.

alan gage

Around here LowE 360 is the standard coating that is highly insulated and blocks solar gain. I specified LowE 180 for my south and east facing windows. It also has good insulating properties (u-factor) but permits solar to enter.

Alan
Timberking B-16, a few chainsaws from small to large, and a Bobcat 873 Skidloader.

woodroe

Passive solar here since 1990. DIY design and build with diy solar hot water add on.
Modified salt box with cathedral ceiling in the SE corner and 2 roof windows .
Kitchen in the northwest and dining northeast. South wall mostly glass with good overhangs
1350 sq ft living area plus full basement. 
Heat with wood only, 4 cord yr ,exposed center chimney. 
Hard to beat passive solar. 
Good luck !
Skidding firewood with a kubota L3300.

Clark

Quote from: Stephen1 on December 06, 2019, 11:26:03 AMI have a log home builder trying to sell me a kit, telling me do not put to much into the passive solar. I think in the dead of winter passive solar will not be a plus, but it is the shoulder seasons...

My parents built a house 3 years ago. SIP construction with triple-pane windows. In-floor radiant heat. Plenty of southern exposure with the proper overhang so the solar gain is limited to the cooler seasons. 
On a sunny day they have a difficult time keeping the temperature below 75. The in-floor heat doesn't help because like all radiant heat, it's a bit slow to back off on it. My dad estimates (propane is shared by the stove, heating system and hot water) that they spend ~$16/week to heat their house, shop and garage (2400 ft2)through the winter.

Clark
SAF Certified Forester

farmfromkansas

I built a passive solar house in '81.  Used 2x6 frame walls, then framed out the walls and staggered the studs for a 12" wall, with double r19 batts.  The house is long ways east and west for the most south wall.  Have 4 large tall windows in the living room, and when sun is shining it will maintain 70 degrees without added heat. I had a mason build a chimney to the basement so could put a wood stove down there, and put a stair to the garage for access to my wood pile outside.
Most everything I enjoy doing turns out to be work

peakbagger

If you havent looked around at the Pretty Good House concepts, its worth spending the time reviewing it. Passive Solar did get quite a bad reputation the first time around in the 1970s. Buildings froze at night and baked when the sun was out. Folks eventually figured out that build a tight house with thermal mass in the right place and far fewer windows are needed. If you look at the earlier designs, they have way too many windows and you will see where large amounts of the windows are shaded.   

Klunker

Quote from: Clark on February 08, 2020, 11:01:36 PM
Quote from: Stephen1 on December 06, 2019, 11:26:03 AMI have a log home builder trying to sell me a kit, telling me do not put to much into the passive solar. I think in the dead of winter passive solar will not be a plus, but it is the shoulder seasons...

My parents built a house 3 years ago. SIP construction with triple-pane windows. In-floor radiant heat. Plenty of southern exposure with the proper overhang so the solar gain is limited to the cooler seasons.
On a sunny day they have a difficult time keeping the temperature below 75. The in-floor heat doesn't help because like all radiant heat, it's a bit slow to back off on it. My dad estimates (propane is shared by the stove, heating system and hot water) that they spend ~$16/week to heat their house, shop and garage (2400 ft2)through the winter.

Clark
Sounds like my house. SIPs, Triple pane windows, no in floor radiant tho. Lots of overhang like your Parents.
I heat with wood in a masonry heater. 2700ish sq ft. Lots of insulation and very air tight.
2-3 cords of wood to heat the house/yr. Our house does warm up on sunny days.
Problem is the sun shines so rarely in that if I depended upon passive solar I'd freeze.
For that reason I'd say build using passive as much as you can but be aware that it will never be able to heat your house comfortably all winter long.
Only way it might work is you'd need a way to store that energy for over a week at a time releasing into the house as needed.
No way of doing that that I know of.
You'd be better off capturing and storing heat from a wood fire.

farmfromkansas

Hard to beat wood heat.  Feels better than a gas forced air furnace.  Especially as you grow older. Think a furnace rather than a wood stove works better, as with a stove, you have to adjust the air intake, and a furnace has thermastat controlled combustion. Important to make it easy to access your wood supply.
Most everything I enjoy doing turns out to be work

Bill

Alot of this is a rehash of things that have been around for some time - but fwiw . . .

I have not built a solar house - helped my buddy with his some ten years back - which used some solar, some wood and some fuel oil ( whilst he was away or sick ) .

I did a fair amount of looking into solar for company I worked for - even did an energy savings project for them - but around 15 years ago - so my info might be dated.

First off - my buddies
pretty much smallish living/heated area  ~ 1100 sq ft  - virtually airtight
really well insulated
solar was just a few windows - more below

Solar ( passive )  - priority - heating -v- ac -v- both ( usually ac being more expensive )

> It must be tight construction - it must be well insulated.
> windows - in a perfect world - need to let heat in and keep it during the winter and keep it out during the summer - can be done with overhangs ( calculated by your northern latitude ) or awnings to leave open in the winter and cover windows with shade in the summer enough to let in mostly light not heat . Even white curtains in summer closed during the day and open at night ( maybe to help let in cool air at night ) ( in winter curtains would be open for sun daytimes and closed at night - hopefully heavy enough to be another thermal barrier to heat loss at windows )
> floors - think heat sink for winter and shaded for summer - best made of something akin to concrete/stone to hold the heat in winter to radiate it into the house at night - typically on ground floor . Make sure they are not heated by sun in summer 
> environment - basics - dark absorbs heat and white/light reflects heat . Diciduous trees on southern side of house ( shade in summer and sun in winter to substitute for awnings ? ? ?  ) and evergreen on northern side ( to break cold north wind ( ? )

Some folks get into heating water(antifreeze ) with sun and mostly using " gravity " ( heat rises ) to move it BUT you need sensors/valves expansion makeup coolant and likely motors .

Not much there but all I can think of - if I remember more I 'll add it.

Wood/fossil fuel backup for long storms ( no sun ) or travel or when sick .

Hope it helps

Thank You Sponsors!