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Keeping Comfortable in the South

 
jared fink
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It seems like most folks out there place their most concern in keep their home warm in the winter months. Call me crazy, but I am way more concerned with keep things at a comfortable temperature during the summer months.

How are all of you keeping your bale houses comfortable in the summer months, especially when it dosne't even drop below 80 at night for weeks at a time?
 
Jeanine Gurley Jacildone
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I'm in midlands South Carolina. Right outside of Columbia. Often referred to as the screen door to hell.

Paul will love this. Plant trees. Plant trees. Seems to be the answer to everything.

Specifically deciduous trees.

Because of the termite threat it is important to have direct sun and dry air circulating on the walls of anything that isn't solid rock down here. But proper placement of deciduous trees can create pockets of cooler air and as breezes flow through they are carried into and around the house.

My old house had areas, just a few feet away from the back door, that were shaded all day during the 'leafy' months. The difference in temperature (cooler) in my back yard was very noticeable.

The old southern houses, whether rich or poor, where usually built with circulation in mind. Windows, doors, should be placed with prevailing winds/currents in mind in order to maximize air movement through the house. This is one of the reasons they were often built somewhat elevated and often shotgun style: Front door opens to a central hallway that leads straight to the back door.

Even in my current 'house' - an RV - I am surrounded by trees. While they don't directly shade my RV, the temperature of the air that surrounds it is cooler than the other RVs who are not surrounded by trees.
 
Rob Rogers
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I am studying installing an earth tube heat exchange system that will run on solar energy. The big hurdle is designing the system to exchange the air in a 3500 square foot house hat was built in 1889. I have seen it done a few different ways, in different redions, so I am incorporating what I have learned, and adapting it ti my region. If you would like to talk more about it, let me know, and I will be happy to shre my thoughts.
 
Brian Knight
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I absolutely agree that landscaping (trees) should be a key long-term strategy. Iam quite certain that the trees shading my old house cuts my AC usage by 2-5X what it would be without them. This is a tough strategy for many sites though. The tree shading my abode is probably 50 years old. A negative side effect is that its mostly a silver leaf maple, not exactly known for root and and branch strength. I may be only one wind gust away from wishing I had called an arborist and settling for more AC use. Most fast growing trees have the same issues.

Window design is probably most important after continuous insulation and blower door proven airtightness. Yes window design for ventilation in shoulder seasons (casements instead of double hungs placed opposite interior doors) but more importantly, avoiding East and especially West windows altogether or choosing very low SHGC glazing shaded by wide porches and overhangs.

Roof and even wall color can have measurable impacts as can including some additional thermal mass. All these passive strategies can help but to be truly comfortable in the humid south, you will need a heat pump of some sort to handle your latent energy loads. I suggest PTAC and minisplits or even a strategically placed window unit.

Be extremely careful with earthtubes in any climate other than very dry. Moisture will condense on the cool tube interior and attract all sorts of mold food.
 
Bryant RedHawk
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Creating a large overhang on the south side is one of the key things to keeping cool in the Southern States. If you look at the old Plantation houses you will see floor to ceiling windows that open both at the bottom and at the top, these induce air flow that removes hot air and creates a gentle breeze effect with in the house. High R value insulation in the roof is a key to lowering the temperature in any building as well as light reflecting coatings and light colored shingles (if you use them). The thickness of a Straw bale house along with the plastering is of great benefit to interior temps when you have a minimum of 4 feet of overhang. My wife and I are embarking on building a single story, timber frame with a roof pitch of 6/12 which will be covered with a metal roof there will be an R value of 30 installed for this roof along with a reflective underlayment to keep the heat down. We will have a 6 foot eave on the south wall and 4 foot eaves on the other walls. our infill will be straw bale for the south and east wall, we are thinking of using chord wood for the north wall and west wall at this time but that may change. We are currently in an RV on site, in the trees while we build our house.

Trees are always a great thing to have for keeping temperatures down. Depending on how much you can spend on windows, triple glazed are best for the south walls but usually you can go with double glazed on the north, east and west walls, at least where we are located this would be optimal. For any home, orientation, breeze, shade, ground covering are the details that will help in the interior temperature.

I've found that morning sun coming in is less heating to the interior than the noon to evening sun for us. We have forest on both sides but it is closer to the house site on the east than the west which is why we don't feel as much heating effect from the eastern, morning sun than we do from the western afternoon sun. Our house site faces south and our long overhang will keep the sun off the windows in the summer but allows it to heat the house in the winter. We have a very good breeze most of the year which comes up the hill from a valley that has a swampy band of trees right at the bottom, most of the time the breeze is around 20 degrees cooler than the still air.
 
R Scott
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Breathable roofs (shake or thatch) make a remarkable difference as well, if you do have partial sun.

There were many mcmansion HOA's here that mandated shake roofs for "aesthetic reasons." After several multi-house fires, the fire department got the city to override that requirement and allow standard shingles for fire reasons. Many homeowners naturally went for the cheaper solution when they needed a new roof. All of a sudden, their AC bills went up substantially, some even needing to upsize the tonnage to be comfortable.
 
Brian Knight
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Even southern locations can benefit from passive solar design and "large" overhang is something better suited to western elevations. 4' is an unusually large overhang for the south side of a passive solar design. Are you talking about a climate with no heating needs?

Great point about attic/roof insulation being a crucial variable. R30 is pretty weak though. I think R40 is a better bare minimum and would prefer R50 or above for most US climates. The thickness of strawbale and its thermal benefits is mostly due to its Rvalue.

I dont think triple pane windows are cost-effective anywhere in the south especially for southern elevations. High SHGC triple pane are rare and expensive in my experience but hopefully triple pane pricing in general will continue to drop. I would love to see triple pane required by building codes to speed the transition.

Thats very interesting about the shake/thatch vs asphalt shingle but surely this has more to do with the Emmisivity and reflectivity than the "breathability". Even if the shakes were installed on cedar breather they likely had a vapor retarder/barrier on top of the roof sheathing/decking. Surprised there was such a universal neighborhood increase.

"The south" can be broken down into southwest and Southeast. Southeast US usually means there is a need for mechanical dehumidification for keeping comfortable to most folks.
 
Bryant RedHawk
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Brian, in answer to your questions. We live in Vilonia Arkansas, which is right at the end of the Ouachita Mountains, our land is on the third ridge, which is the northern most ridge of this geological feature. We are building on a pre-existing footing. and I have mapped the sun travel lines for our location in each season.

The reason we will have such a long southern overhang is so that we can have a southern (best views) sitting porch/deck that is covered and screened. The Summer Temps for our area range from the mid 80's that start at the end of March, normal years, to above 100 starting in July and going through the first week of September again, in normal years. Winter Temps can get as low as 0 but are normally in the teens, the winter highs can be up to 70+. Holding solar heat in, in winter is why I am thinking of triple glazed windows for the South Wall, (we have a company that builds them near by and they are only about 50 dollars more than a double glazed when picked up at their facility. Being still in the planning stage for the "big house" allows me to continue looking for viable solutions and ideas. I agree that a higher R value would be better, and again I can go higher, but I know that anything under R30 would be foolish, my wife is wanting to keep the build costs low so we can get it finished without any loans.

Arkansas is pretty humid year round but not unbearable until around the end of July and through August, September is when the humidity starts to wane. My goal is to build so that I can stay comfy with a wood burning stove and small window type air conditioner. We are out doors for the majority of the day light hours.
 
Topher Belknap
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jared fink wrote:Call me crazy, but I am way more concerned with keep things at a comfortable temperature during the summer months.


You're not crazy; you live in a cooling climate. Don't mind us Northerners, we live 6 months under a blanket of snow, it makes us a tad obsessive.

Bryant RedHawk wrote:my wife is wanting to keep the build costs low so we can get it finished without any loans.


Often loans are cheaper than ongoing expenses. Around here, it takes a LOT of insulation for the loan to be more than the monthly cost of the fuel saved.

Brian Knight wrote:High SHGC triple pane are rare and expensive in my experience but hopefully triple pane pricing in general will continue to drop.


I think you meant LOW SHGC for Cooling climates.

Brian Knight wrote:shake/thatch vs asphalt shingle but surely this has more to do with the Emissivity


What emissivity value do you use for thatch and shake? My SWAG would have put it about the same as asphalt shingles. Most things are pretty close, with exception of shiny metals.
White (or very light) colored shingles are recommended.

Radiant barriers in attic spaces can be helpful.

When it is cooler outside, open windows. On the windward side, open a few windows as low on the house a possible. On the leeward side open, about half that area, as high on the house as possible. Open all doors in between.

Ceiling fans should blow down. Only use fans when they are blowing onto a person (or possibly in low windows, see above).

Do everything you can to avoid putting water into the air.

My experience is with heating climates, so take with a grain of salt.

Thank You Kindly,
Topher
 
Bryant RedHawk
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Tropher, Thanks, that is good to know. My wife is Dutch/ Native American and I am Irish/Native American so we tend to not go into a debt situation if at all avoidable (keeps me from getting a lumpy head). It is good to know that if we need to, we always have that option available, and I now have a new angle to explain that it isn't as bad as she will think it is.
 
Brian Knight
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Tophers tips on nightime flushing for multi level homes is great. I avoid AC usage for much of the year using this method on my one story, blowing into the sleeping room and out of the opposite side of my home. Its those nights where the temps dont drop and pollen is high that I have to seal up, and turn on the comfort machine. If it were not for the precariously perched silver maple shade and weatherization efforts, it would be MUCH more often. By weatherization efforts, I mean air-sealing and adding thick attic insulation. This is the main way Ive cut my AC usage and dropped heating costs substantially.

You want high SHGC on the South facing windows. Low SHGC on east and especially west, better yet, NO west windows. But perhaps most importantly, Low Uvalue.

And the low Uvalue is the problem for southern window where you also want high SHGC. It takes a good balance of Uvalue and SHGC. For whole window values generally, .3 or lower for Uvalue and .5 or higher for SHGC is the best of the current available window technology. This is done with a special type of lowE glazing that not all glass companies make. Be sure that the window company uses a glass that is High SHGC but also has a lowE coating which is one of the primary way that windows improve their Uvalue performance.

Those are thoughts for the majority of US southern climates that still have heating needs. If the house requires no heating then you dont need passive solar windows and ignore SHGC values for UValue and Visual Transmttance.

Bryant, looks like you are in building climate zone 4 which has R49 for the Attic international building code minimum which I think is a fairly cost-effective level to hit. I also suggest mapping the overhang shade of your south facing wall as 4' is about 2.5x longer than typical for an average height wall at that latitude.

As for common finish roof material, painted white metal seems to be the clear winner in energy performance. Just because its shiny, doesnt mean it performs well with emissivity.



 
Brian Knight
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Iam feeling like I havent plugged the air sealing thing enough here. R49 attic insulation assumes that you are achieving a certain level of air-tightness. International code says ACH 50 of 3 but I think a more cost-effective level to hit is 1.5. I highly suspect that the upcoming 2015 energy code update of poorest performance allowed by law, in terms of air-tightness, will be lowered. Current Insulation levels are not effective without confirming air-tightness first.
 
Marianne Cicala
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Being raised in the south, I hear ya! I remember years ago, we bought a little piece of land and scrapped materials to build a shanty kind of hut. I found scrap pipe (corrugated and about 30' long, about 24" around). We dug a ditch about 4' deep, cheese clothed & triple screened 1 end and dropped it in the ditch, covered it with gravel & rocks then dirt. The other end came into the building & had a damper. To cool this space, we opened the damper then opened a awning window, pretty high up. It was amazing how rapidly the cool air would move through. Happy thing, in the winter we also used this to take the chill off. Pretty simple and pretty effective.
 
Topher Belknap
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Brian Knight wrote:If the house requires no heating then you dont need passive solar windows and ignore SHGC values for UValue and Visual Transmttance.


I wouldn't say 'ignore' them, but rather for cooling only climates, you want low SHGC. Think of visual transmittance, as window tint in cars, and decide accordingly.

Bryant, looks like you are in building climate zone 4 which has R49 for the Attic international building code minimum which I think is a fairly cost-effective level to hit.


Sadly, it is possible to have R49 not be cost effective, if one uses expensive insulation. In attics there is generally a lot of empty space, which can be filled with a low cost insulation in massive quantities (like Cellulose). Higher R-value per inch is not important in this circumstance, go for high R-value per dollar.

As for common finish roof material, painted white metal seems to be the clear winner in energy performance. Just because its shiny, doesn't mean it performs well with emissivity.


As with all things green, details matter. And empirical data, preferably local empirical data (and I don't mean anecdotal evidence, but actual numbers), matters as well.

Thank You Kindly,
Topher



 
R Scott
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Topher Belknap wrote:What emissivity value do you use for thatch and shake? My SWAG would have put it about the same as asphalt shingles. Most things are pretty close, with exception of shiny metals.


It isn't just emissivity. Any heat they do collect is convected OUT from the cooler inner air because they are essentially open. These natural roofs are the opposite of sealed. They even act as an evaporative cooler. Much the same as Paul suggests large trees work.

They work well, but completely differently than we are taught to think of modern construction. If the roof is working like that, you want to leave the ceiling UNinsulated so the heat will continue to rise out of the living space if you are in the true south without air conditioning.

But if the overnight low is 80 and humid, there isn't much you can do but sweat while drinking your sweet tea on the porch that catches the best breeze. Unless you have trees to cool the surrounding area and then it stays in the 70's.
 
Topher Belknap
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Brian Knight wrote:Iam feeling like I haven't plugged the air sealing thing enough here. R49 attic insulation assumes that you are achieving a certain level of air-tightness. International code says ACH 50 of 3 but I think a more cost-effective level to hit is 1.5. I highly suspect that the upcoming 2015 energy code update of poorest performance allowed by law, in terms of air-tightness, will be lowered. Current Insulation levels are not effective without confirming air-tightness first.


Well insulation and air tightness can be separate, though they are often related; however I think you are right to harp on it.

Passivhaus standard is ACH50 of 0.6. Passivhaus builders around here are striving for, and hitting 0.3 - 0.4. One of those builders, pays the first five years of heating bills for any house he builds. In a climate where many people are paying $5000 or more per year for heat, that offer means that the builder is getting the payback on that air-sealing and he thinks it is cost-effective (at 5 years). Lest you think that he is just bumping the price, one recent house he built came in under $165 per ft^2.

Thank You Kindly,
Topher
 
Brian Knight
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I disagree that having an un-insulated roof can be a good strategy in any cooling climates. Shingles and thatch do not have any significant cooling effects other than shade. If they are in contact with the roof structure then the laws of physics applies to them the same as any other roofing material. I think the emissivity of shakes is good but the reflectivity is much more important and according to this paper from FSEC the reflectance values of painted wood is similar to asphalt shingles. Most research points to color as the main variable that effects attics and roof temperatures. http://www.fsec.ucf.edu/en/publications/html/fsec-cr-670-00/ I couldnt find any values for thatch in a quick search but would expect good values for both reflectance and emissivity. Still, reflectance is the main value to consider.


Night time flushing hinges on closing your windows up in the morning. It works because the air-sealing and insulation keeps the cooler temperatures of the night in place throughout the day. Without air-sealing and insulation, the temperatures inside the house will stay closer to the daytime outdoor air temperature especially if you forget to close the windows or build a roof that has no insulation or doesnt stop airflow.
 
Topher Belknap
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R Scott wrote:If the roof is working like that, you want to leave the ceiling UNinsulated so the heat will continue to rise out of the living space if you are in the true south without air conditioning.


To clear up a misconception that I get a lot: Heat doesn't rise. Hot air rises.

Thus, in order for an uninsulated ceiling to be losing heat from inside to outside, the inside temperature must exceed the outside temperature. This is not a condition I want in my house on a hot day. An uninsulated roof on a building would therefore be limited in coolness to the outside temperature. If it is comfortable outside, why not be outside.

Thank You Kindly,
Topher
 
Brian Knight
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Ha! I like that explanation much better. And if the moderators allow, I present my newest blog over at the WNC green building blog collective that was inspired by this thread. Thanks all for the help!

http://wncgbc.org/blog/postings/keeping-homes-cooler-and-more-comfortable-in-the-summer/
 
R Scott
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Topher Belknap wrote:
R Scott wrote:If the roof is working like that, you want to leave the ceiling UNinsulated so the heat will continue to rise out of the living space if you are in the true south without air conditioning.


To clear up a misconception that I get a lot: Heat doesn't rise. Hot air rises.

Thus, in order for an uninsulated ceiling to be losing heat from inside to outside, the inside temperature must exceed the outside temperature. This is not a condition I want in my house on a hot day. An uninsulated roof on a building would therefore be limited in coolness to the outside temperature. If it is comfortable outside, why not be outside.

Thank You Kindly,
Topher


Yes, the hot air rises, and the cool air is pulled in through the open vents in the basement or crawlspace. I don't know all the reasons it works, but know it did from personal experience.
 
Brian Knight
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There may have been a cooling effect from the thermal mass of the crawlspace/basement but these spaces were being fed by outdoor air. The more humid air flow, the more risk of condensation on colder surfaces which could be wood and other things that want to grow mold and decay down there. Unsealed crawlspaces and basements are also generally high in radon and other unhealthy soil gases. In the winter, or heating season if there is one, humid air flowing in this fashion will tend to rot the cold roof areas where the air is exfiltrating.
 
Jeff Stagg
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I live in North Georgia and have been in my bale for about a year and a half. My biggest concern when designing the house was keeping it cool without A/C, as my home is also on an off the grid PV system with limited battery storage. To achieve passive cooling I first designed the home with a wrap around porch properly angled to block the suns rays from reaching the windows. I opted for a vaulted ceiling with 4 opening skylights (no attic) to help vent the ceiling. I super insulated the ceiling with blown in cellulose to achieve R-65. The exterior roof is un-painted galvalume, this has a reflective quality to it and I believe helps reduce heat gain through the roof. I am using clay based cob like plaster to coat the bales up to 6" thick. I have noticed an extreme difference this summers with 80% of the interior plastering completed vs last summer when only about 30% of the interior was plastered. The thermal mass of the clay holds the coolness all day. My daily summer routine is to close up the house by 8am and then open it up around 8pm. The nighttime temps normally go below 70 and have recently dipped below 60 allowing me to get the house down to the mid sixties by morning and keeping it under 72 before opening it up again. The real challenge is humidity and overall dampness. The humidity inside the house is usually 5 - 10% less than the exterior humidity. I attribute this to the clay plaster absorbing some of the moisture as we keep multiple ceiling fans going to circulate the air and move it over the tile floors and clay walls. But even at that, humidity levels are typically 75% or higher inside the home throughout much of the summer. We love those occasional dry spells but they are few and far between during the Ga. summers. Now winter time is a completely different story - we heat the home with a free standing wood stove and it keeps the house mid to upper 70's all winter long with interior humidity of less than 20%. Winter is my favorite time of year to be living in the bale - it is so warm and toasty you can barely stay awake!
 
Brian Knight
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Thank you Jeff for that wonderful, detailed account of your home. Sounds like your research and hard work is paying off.

Just wanted to add that the increased performance of the interior plaster could be due to the increased airtightness as much or more than the increased Thermal Mass. Would love to hear accounts of before and after plaster blower door testing if anyone can help out.
 
Jeff Stagg
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Hi Brian,

Glad you enjoyed my little write up. It could be attributed to the increased air tightness, more than likely it is a combination of being tighter and having more thermal mass. Whatever the case - it is working! A reason for the interior humidity could be attributed to the fact that I am still plastering the interior and it takes about 3-4 weeks for the plaster to fully dry. Since I am plastering all summer - I always have walls at different stages of drying and thus putting moisture into the air. Next summer the plastering inside will be complete and I will be able to get a better read on interior humidity. Take care.
 
D Brown
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I'm coming into the conversation pretty late but I have enjoyed reading everyones into. Thank you all!

I live in Chester SC and am planning a home build. No set plans yet, but we are leaning towards cordwood with a metal roof. (I havent managed to talk the wife into a living roof, yet...)

Cooling is a must for us. We love a constant 70 degrees year round. (I can almost hear some of you gasp already, lol) Our home build will use a heat pump, probably in a crawl space so that we can take the easy way out and keep the house temp and humidity under control.

Hey, when you have 3 small kids and busy lives, simplicity is sometimes worth the extra expense! Anyway, despite this, we do want to be as green and energy efficient as possible.

I hear a lot of people talk about air circulation and vents or opening skylights on the roof. I can definitely understand the benefit of having air movement and being able to let the hot air escape and let cooler air in. I'm wondering though, being in South Carolina, wouldn't it be better to keep that solid sheet of R40+ roof over head rather then adding openings in the top?

Just a thought.
 
Brian Knight
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Thats an excellent question on the skylights as I was thinking the same thing. Notice that Jeff claims an R65 for the roof insulation which is a very respectable level of performance. Punching 4 holes, adding up the square footage with drastically reduced R value for the skylight Ufactor, has the effect of bringing down the overall Rvalue of the roof quite a bit.

In the summer time, they are probably contributing to overheating despite the venting. I feel that windows on walls with interior doors open ventilate a home just as well as clerestories and skylights. These building envelope penetrations increase air leakage, decrease R value and the fenestration; skylights/poorly designed clerestories increase unwanted solar heat gain. All of this drags down the performance of the envelope more than the venting contributes to it.

With both heat pumps and night time flushing, weatherization should be one of the main goals: Airtight and Continuously Insulated. This is the most proven way of keeping heat in during the winter and out during the summer.
 
Jeff Stagg
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I do not notice much heat gain from the skylights - they are very good quality and heavily glazed to reduce UV rays from heating the interior. The pitch of the roof being a 10/12 also prevents the sunlight from directly penetrating. The real upside to them is that they provide diffused interior lighting throughout the house during the day/moonlit nights reducing energy consumption on lighting and they allow the cool night air to fall into the home from the ceiling, like a waterfall of cool air. I feel without the skylights that the house would not cool down as much as it does at night - this is quite evident on stormy nights were I keep then closed and the house barely budges off its daytime highs despite all windows being open. I think it is fair to say that whatever inefficiencies the sky lights may have during the day is more than made up for by the amount of venting and cooling the allow during the evening. In the winter they are more valuable than one would imagine, with the wood stove occasionally belching smoke during reloads/restarts, a cracked sky light quickly clears the smoke out of the house. We also keep them cracked slightly on those days were it is too warm during the day to have the wood stove going, but we keep it going because night time temps are dropping below freezing. Just a small crack keeps the house from over heating and keeps it quite nice inside.
 
Brian Knight
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Jeff, thats a good explanation and it sounds like your design is working great for your needs. I hope you dont mind if I use your roof as an example for some math to help other readers understand the impact of skylights on roof insulation. Please feel free to correct my arbitrary but average variables.

Lets assume a roof with 1500sqft above the heated space. Ignoring the thermal bridging of the roof framing's impact on insulation, lets use the R65 mentioned.

Assuming (4) 2'x3' skylights with a Ufactor of .33, this makes up 1.6% of the total roof area (again ignoring thermal bridging of skylight framing).

.33(.016)+.015(.984)=Total Ufactor .02 or an R value of 50. By adding the skylights here, we have reduced the roof Rvalue from R65 to R50. That brings a roof that was performing above and beyond code to the poorest performance allowed by international law in a zone 4 climate. Granted, most people arent building to code unfortunately. By exceeding code levels with the R65, Jeff has managed to stay balanced compared to roof code baseline performance. I would guess that most builders in Jeff's area are achieving maybe R30 for un-vented roofs in N Georgia (without the skylight math) so he is obviously still doing MUCH better than average unvented attic new builds.

All that math also ignores the added air leakage which could be a bigger source of heat loss/gain than the reductions in R value. Its the solar gain from skylights that are the real killer in a cooling climate though. North facing seem to be the least troublesome for those concerns and the steep slope facing north would help even more for reducing unwanted solar gain. Also remember that skylights are one of the main sources for bulk water leaks. I personally would not install one that wasnt a Velux or had a similar integrated flashing system.

As for the ventilation, I believe Jeff when he says the skylights improve venting performance. I just think a well designed home can get equal performance with the right sized windows on exterior walls placed opposite interior doors. This is also true for daylighting. In most cases, avoiding skylights will help simplify, reduce upfront costs, and improve overall performance.

One of the most important functions for Jeff's windows may have been unintentional. By using wood combustion inside the living space Jeff's reduced roof Rvalue is probably of less consequence than the benefit of venting smoke and ash through the skylights. For those of us trying to avoid the Indoor Air Quality problems of indoor wood combustion, we might need to pay closer attention to the impacts of skylights on both heat loss and gain.
 
Jeff Stagg
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Brian - I appreciate you taking the time to analyze the impact of skylights on overall roof efficiency. I agree with everything you mentioned. I do have Velux skylights with the proper metal roof flashing kit and am 100% certain water leaks will not be an issue. With everything said on keeping a home cool in the Southern summer heat, my personal experience has been that cooking indoors is the biggest killer to keeping a straw bale home cool than anything else. Because of my homes design with very high vaulted ceilings - any daytime heat rises out of the day time living space on the ground floor up onto the ceiling and is easily vented out via the skylights once the sun sets. The homes interior temperature is then re-calibrated to within 2 degrees of whatever the night time lows happens to be. The windows and skylights get closed and this temperature is held all day with no more than a 5 degree rise in interior temps. It is rare, even in the hot Georgia summer, for my interior temps to exceed 75F, unless I bake a loaf of bread or make pizzas - then all bets are off. A 500F oven has a peculiar way of killing a cool straw bale!
 
Brian Knight
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Great info! It makes me appreciate the owner and designers work on a recently completed home of ours. The wood burning pizza oven is in a separated living space. We airsealed and insulated the separating wall and weather stripped the door and pass through countertop windows. We added more operating casements than usual on all 3 exterior sides. I was more worried about the smoke factor but the owner says it draws great and the room doesnt effect the main house, but it is in a cooler climate.

In the non-combustion appliance vein, I usually recommend people get induction cooktops. They are the most efficient and contribute to the least unwanted heat while being easiest to clean and arguably less indoor air concerns. They havent invented an induction oven yet unfortunately. I can say that I am envious of my clients oven though. That wood fired pizza is good.

The performance you describe is very good. It sounds like you have some good airtightness and obviously good insulation. I was skeptical that your humidity concerns would go away but I think baking bread might take care of that. So Jeff personal question, are you entirely toughing it out with no AC?
 
Jeff Stagg
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I built a cob pizza oven last summer and do enjoy cooking in it, but find that the 1 1/2 hour warm up time is not always conducive to my schedule. I got a nice gas/charcoal grill unit with a side burner that I do the majority of my summer cooking on. My kitchen oven is a non-electric Brown Stove works propane model - best oven I have ever had - cooks breads and pizzas wonderfully.

Yes - absolutely no A/C. Being on a an off the grid PV system - A/C does not really fit into the plan. I have tried using a de-humidifier, but have not been impressed with the results. I have been burning scented candles in the basement to reduce humidity and to freshen up the air down there and that seems to work better than anything else I have tried. Currently 85F outside at 4pm and we are sitting at 73F inside. Who needs A/C?
 
Brian Knight
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I like it! Well, me and my momma having yankee blood, would want it depending on the humidity at said 73 degrees F..
 
Jeff Stagg
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I have Yankee blood too - born and raised in PA. I have always had A/C and felt it a necessity for summer survival. When I decided to retire from Corp/Am at 43 and homestead for the rest of my life I knew I had to toughen up. My whole purpose for building a totally off the grid bale is to escape wage slavery. I designed my home not just to be efficient, but to be as bill free as possible. A/C, central heat, a dryer, a dishwasher, etc are all luxuries the poor homesteader cannot and does not want to afford. The bodies ecothermic cooling system adjusts to a more natural environment very quickly. Cold showers year round also help the bodies natural systems work even better. I wear my independence from artificial systems as a badge of honor - it is living true and it feels great. Honestly - 73F is not really roughing it anyways. I used to keep my A/C set at 72F and it ran all the time.
 
Brian Knight
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Very admiral and I envy your toughness. Comfort is a broad term and many of us have gone weak. I think AC has a place in Permaculture but it needs to be run on renewable energy. Comfort is the subject and it is attainable. There is a huge difference in comfort to most people at 73F if the humidity is 40% than 70%. I would choose 40% every time.

Please dont take this the wrong way Jeff, as Iam presenting ideas for the broader public, not picking. I think staying on the grid could have less environmental impact and provide a more affordable means of being hooked up to the perceived life support of AC in the humid south. PV + Grid= more convenience, possible less cost with equal or less costs to the environment. That being said I think Jeff's lifestyle is probably less harmful to society and the environment than mine.
 
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