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Posted By zehboss on 27 Feb 2011 07:00 AM
Have you been in or built an Earthship? Typically they have a solid wall of windows on one side. This is typically more natural light than a standard above grade home. I have built several underground homes and none of them have been cave like at all. All were lighter, and brighter than most homes.
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Zehboss,
I don't think some of the critics here have been in Earthship. The reason I say this, is because they're critics. We have had hundreds of visitors, and many of them have been overnight stays. Invariably, they are amazed. The longer they stay, the more they like it, at which point I tell them, "Build your own!" :-)

Doing high mass homes well requires significant knowledge, engineering and modeling experience. Humidity has to be dealt with in any home, especially in the SE US. This is not a function of the mass of your house. Mass stabilizes temperature over time. This limits the peak highs and lows. It allows for solar absorption and release of the stored energy back into the house overtime. If your home overheats it is not designed well based on its interface with it's local micro climate.. If your home is to humid you do not have your air exchange and dehumidification system designed well, or your house is not tight. Mini-splits can dehumidify but are not a very efficient way of dehumidifying without substantial cooling of the home.

You built a home with a design temperature range of 47 to 83 degrees and without regard for humidity control? So, you designed the house to be uncomfortable and are complaining about its performance. It sounds like you got what you planned.

60 to 75 degrees is the maximum design range for human comfort. Humidity needs to be controlled in the 30 to 60% range for health. Accomplishing this passively requires a heat and cooling flux reduction of in excess of 90% over a coded home in most areas. You also need enough internal mass to average out diurnals and max hot and cold time frames to reduce auxiliary inputs. This is typically in the millions of pounds of mass. All the mass needs to be contained inside the insulation boundary to be effective. Mass only homes need in the range of 24 foot thick walls to work, this is simply not practical. The proportion of mass needed is dependent on the amount of none thermal bridged insulation of the envelope. At total insulation of R-50 total assembly insulation the amount of needed mass becomes manageable.

Liquid absorption based dehumidification systems are the only efficient ways of controlling humidity. LiCl based systems are currently being made for labs and for industrial buildings. These systems can remove up to 60% of the humidity in the air in a single pass. They do minimal cooling and use very little energy in the process. Mini-splits simply cool the air to a point it condenses water on the chill plates. running in dehumidification mode just runs the air through at a slower rate cooling and better dehumidifying a smaller volume fraction of the air.

LiCl systems can use solar heat to evaporate the water content in the liquid desiccant. But, this requires a fair amount of custom building and understanding of the systems. The commercial systems usually use a heat pump to dry the water out of the fluid and use the other side of the heat pump to cool the liquid desiccant back down. Building high mass and or alternative construction technique homes are much more complicated to build, design, and get them right. There are lots of examples of poor execution of them by people with limited experience who make bad decisions in the process. There is not a simple prescription for making non standard designs work.


Brian

Brian, Thanks for the informative info. However, I do not recall complaining about our home at all. I wouldn't want to live in any other home. It is EXACTLY what we wanted. Yes, humidity would have to be dealt with in your climate. A cave can be very cool, but water is dripping off the ceiling. I used desiccant wheels (LiCl) in an industrial environment. I'm not going to pretend to know the best methods for dehumidification, but I'm fairly sure there are products out there that do the job, without forced air. I stayed in a hotel room recently in FL, and there was a portable unit there, that worked very well.

Ummm, Zehboss, if you install a dessicant wheel plus air handling to condition each room, are you not installing hvac in contravention of OP's question is mass enough?

And if nonstandard houses take expert knowledge and engineering, why do you blithely tell OP go for it if he has the time and energy?

If my house is a failure because I can't run the mini in the summer for more than five hours a day, and my power bill for a very ugly January was $15, what's your definition of success?

OP writes of his friends in Colo who can't live in their earth ship because it is unheatable, and I'm guessing can't sell it either given proper disclosure. Is that success?

OP is courting the same result. The cloud cover here in Dec is 90 percent. Each grey day digs a little deeper hole unless you have a alternate, big heat source. Take it from me, and I'm not the only one. Here is a report of a high mass zeh home in Tucson where high mass turned out to be the problem. http://www.toolbase.org/PDF/CaseStudies/TucsonZEH1Report.pdf

"Thermal mass is an energy benefit when passive solar design is applied to a home. However, for production housing where passive solar design is often not feasible, a home having high h
thermal mass may lead to additional heating energy use."

Posted By toddm on 24 Jun 2015 07:28 PM

OP writes of his friends in Colo who can't live in their earth ship because it is unheatable, and I'm guessing can't sell it either given proper disclosure. Is that success?

Perhaps the QUOTE  button should be used, when quoting somebody.  This isn't even close to what was discussed.  Also the Link from Tucson isn't even relevant.  It wasn't a bermed home!  Bermed homes are inherently cool.  Basically, they put a bunch of rock and sand in the dessert.  And it heats the house.  Who would have expected that?

Internal thermal mass is always a benefit when used correctly. It is a problem used incorrectly. I made no judgement on anyone's home except to point out that doing things incorrectly causes problems that are not the fault of the thing which was used incorrectly. You complained about the humidity, heating and cooling and blamed thermal mass. That was not the problem. Not using insulation is a problem, not dehumidifying in a high humidity area is a problem, not holistically integrating the micro climate and the underlying design physics is the problem with each of the buildings in question. Building self heated, self cooled, self dehumidified, self electrified, utility free, homes that increase your cash flow, health and wealth is significantly complicated and requires study due diligence and care to do successfully.

Brian

  You complained about the humidity, heating and cooling and blamed thermal mass. 

Please provide the quote from my post.  Because I would never complain about this.  This is the strength of the home!

Jim I was responding to a different part of the this thread on the last two posts. There are too many crossed paths here. I was typing when you posted. Then I posted. This put your post in the middle.

Brian

Good heavens zehboss. I am not complaining that thermal mass is the problem but rather saying that it is only a partial answer in the midatlantic thanks to high humidity and sketchy passive solar. Clearly mass tempering is the reason my house is so easy to cool in the summer; passive solar works reasonably well outside the six weeks from 12-1 to 1-15. And mass is enough by itself in spring and fall. That said, beastmaster won't be happy without mechanical dehu and a woodstove, a furnace or similar nuclear response to 14 straight days of grey. No amount of mass will reverse the flow of heat when it's below freezing outside 24-7.

Ever look at Thorston Klupp at the cold housing research center in Alaska. R-75 walls, R-130 roof,R-60 foundation. High internal mass as I recall.
Near artic circle 50 below in winter. He has a 5000 gallon water tank insulated to R-75 that he can heat to 180 F, with solar. He claims to coast with no sun for 6 weeks. He uses a masonry heater for the rest of the winter. It is the first PH certified in artic circle. I built a house in Park City, UT, at 7000 feet at ski area 60 " thermal mass under foundation, 10,000 gallon water tank. It can coast in winter for 2 months. R-60 walls, R-30 perimeter and under mass with R-113 in the roof. It is over 10,000 square feet of luxury home no compromises completely off grid. Runs on a 10 kw solar and 2-2 kw wind turbines. You can design to successfully meet such extremes but there is a lot to making them work well. I call what I do H.I.D.E.N. Systems design. Holistic integrated design using engineered natural systems. I cringe when people say it can't be done because I do it all the time.

Brian

OK you're starting to grasp the notion of cloud cover even if Park City Ut and Montgomery Co. Md occupy different ends of average daily insolation charts. Not so cool that you've shifted beastmaster from his earthship to a Passivhaus. But good on you, you have warned him backhandedly that sometimes it takes pv, a wind turbine, a 10000 gallon heat storage tank, a masonry heater and lots and lots of insulation to get to "self" heating. Oh yes, and a dessicant wheel. You might recall that beastmaster likes tires because a yurt at $30k is too expensive.

I cringe when people push THE ANSWER in building envelopes with no regard for cost or minor considerations like the climate.

It wouldn't take much pv to make my house a zeh but the return isn't there, and I'd still need my stove ($2300) and minisplit ($1500.) Unlike you I understand that perfect is often an enemy of good.

Fairbanks AK in the dead of winter is worse then all of them for solar insolation. Your cherry picking and looking to be contrary. Reynolds god father of earthships insulates the back of the mass walls when he builds Earthships for others in any climate that is cold or hot for a sustained period of time. The exception is in third world countries, as a charity. Where something is better than nothing.

He charges in the high $200s per foot for him to bring crew and build one in the US. His early buildings often performed poorly at weather extremes. He has been sued multiple times for buildings that don't work. Earhships done right at passive houses.

Encasing a house with 12" of recycled styrofoam has a material cost of $6 per foot. Triple pane windows an extra $1 a foot. This is brute force and not always the best method. That is a small price to pay for a building that becomes passive. Yes, There is more to it to make it work. The point is the cost to go passive is less than the reduction in on going utility cost.

Humidity control is something you plan on handling if the climate calls for it. It is best done on a whole house basis. I do not know why you keep talking about one room at a time. I never mentioned room by room. Someone else mentioned having a portable one in a hotel room, sounds like another bias.

Your example of the Earthship that was built wrong and doesn't work is a perfect example of not investing in proper design and thermodynamic modeling up front causing a major problem down the road. The point being if you are going to do none standard stuff you need to educate yourself or invest in someone that has the knowledge.

Earth ships are not inexpensive, unless you provide all the labor, and are quite resourceful. I helped a friend build a net zero house for $1 per foot before. All recycled materials, free labor, labor in exchange for material, salvaged old building, inherited property with well, septic and power, collected styrofoam and other materials from dump for a year. Had a used solar system donated to him. It was something he did based on his circumstances that made sense to him. Very few people are willing to work that hard.

If you DIY your solar system it is hard to believe it will not pencil out. You can get blem panels for as little as 34 cents per watt now. Again it is work, resourcefulness and ingenuity to get it done. Most solar installers charge a lot.

Brian

If using climate data from the location where the OP is building -- answering his question, that is -- is cherry picking, you got me.

That's some expert advice there. Someone mentioned seeing a portable desiccant wheel in a hotel room so that's a possibility. Maybe.

When I last priced pv, and it was a while ago, the killer was the below roof costs, cabling, inverter, grid interface, which don't shrink as system size falls. That and Pa won't pay me subsidies unless a certified installer files the application. But if you want to help me, internet service is my current bugaboo. Buying it unbundled at a less than extortionate price is an annual nightmare. Costs more than my power bill in fact.

Internet access cost is ridiculous. I live only a block from a free high speed Wi-Fi access point. An extended service antenna and a directional dish and magic happens. I feel your pain. When I move out on property again I will be paying through the nose again for internet. I have been in several homes were internet is the only utility bill.

Climate data is great. I pointed out the first example, a Fairbanks AK home that has almost no sun for the winter. You picked the Park City home as an example of the information being in question. That is selective use of information to support your point instead of chatting about the information. Again the point is climate matters, but if you understand the micro climate you can build anywhere and be close to passive at a reasonable cost.

Brian

Personally, I like all the methods of green building. Geothermal, solar, wind, SIPs, berming, and many others. They all have a niche to fill. It is unfeasible to build a bermed earth home like mine, with 5' thick walls, in the city. Geothermal retrofits nicely to existing homes, and is feasible in city residences. The simplicity of the tire bale home makes it a great option for those with acreage. Others on this board, who seem much less tolerable and flexible, should take a look at the tire bale home. If you're in Colorado, look me up. I'll show you not just my home, but others, both tire bale and rammed earth, that will blow you away.

It's nice to know that a product that is a disposal nightmare, in that the dumpyards attract mosquitoes and disease-carrying rodents, can be put to good use in a construction project, and that the home can be an incredible energy-independent structure. Between my 2 friends, who own tire-bale homes, and myself, we're got roughly 60,000 tires behind our walls. Are you reusing the tires that you'll dispose of in your lifetime?

I don't want to drag this out, Zehboss, but you brought up Park City as an example of your work. I merely pointed out that it is in no way comparable to beastmaster's building site. High mass passive solar is great in the west. Not so much here because there often isn't enough insolation to budge the needle. Building it here without hvac capable of heating the home without sun is a major mistake.