Brian Knight wrote:The more simple the plan, the more it can make sense to pre-plan so its certainly not a waste of time especially with generalized bubble ideas. For rough budgets, knowing a square footage and rough price per sqft is useful at this point too. Usually site work is one of the biggest unknowns and reason for variance.
I think connected greenhouses are usually a bad idea because they have more temperature extremes and humidity than what we want for our homes. My question would be why attach? Iam guessing the reason is to save on excavation and infrastructure costs in relation to your earth bermed north wall.
Good passive solar designs will perform best with the right balance of air-sealing, insulation and fenestration. Greenhouses usually complicate things and hurt performance overall when sharing a wall with the house.
My idea of the best annualized western elevation, in our mixed-humid climate, would be NO windows with an airtight and highly insulated wall with wide roof overhangs and preferably big deciduous shade trees blocking the setting summer sun. The more the wall, or western elevation deviates from that description, the more it will negatively influence the home's performance on a net annualized basis and the wall (and house) will be subjected to higher humidity from the greenhouse.
Willy Walker wrote:"If you are going to go with the conditioned crawlspace, I suggest exterior insulation for the foundation, right down to include the footers." - I like this statement. I had not thought about this. My initial thoughts are to use a spray foam inside the crawlspace, I'm not sure if the spray foam can be in contact with the soil. I have this on my questions list for the spray foam installation company. Is your point to insulate on the exterior so that the crawlspace and footers are a thermal mass? In my thought process of interior insulation, this would not be the case.
I like the idea of the amount of power the HPWH uses. I also like the idea of letting a device perform double duty. Thus why I was thinking of putting this in my attic. I haven't figured out if there would be sufficient heat to warm the attic in the winter.. I am hoping to avoid adding much heat in general so I need to be careful here. It is possible that in lieu of the HPWH i could install a standard water heater and add a solar WH in time, something I want to do any how. I need to get in touch with a radiant heat supplier so that I can figure out cost and better understand the details. I really like the idea of a drain back system, draining back into the crawlspace to serve as as a pre warmed thermal mass for which the house air is circulated around. I see I have a few questions in general still about heating my home. Of course i know all to well about the wood stove. It is my hopes that this becomes a sunday enjoyment and not a constant..
I secretly understood but just didn't want to admit it that by switching from a slab to a conditioned crawl, I'm loosing the title "Passive Solar". Or at best, its not a selling point anymore. I just don't think I can do with the slab though.. So sad. At least though, I wont have to turn on many lights during the day!!
Doug - Can you clarify this statement? "I think the effect of a berm which is insulated off from the living space is minimal. If thermally connected to the living space as well as ground, it has the ability to absorb infinite amounts of heat, not good in winter. " What kind of advantages can I expect from my first floor, north wall being earth bermed? The lot lends its self to an earth berm or not as the grade could be taken either way. One thing I do like about the earth berm from a cosmetics approach is that I don't want any (maybe one in a bathroom) north side windows. However this is the side every one will see, so burying half the wall will make my house almost look normal as the wall will be pretty blank. My thought on function is that the earth will provide a constant temp, out performing even the best insulation techniques. My thought is to insulate the outside of the wall (to the footer is a great idea) and I'm not sure on the inside. A concrete wall is not as functional as a stud wall for living so... Still on the fence. My other alternative would be to not earthberm (totally changing my theme) and utilize a SIP wall with no windows..
I know sharing this idea via a web forum in text only and it is crude at best. But I really am just putting this all together. Any help, ideas, ect, even if I didn't ask for it or it doesn't sound like its in my plans are excepted. Very soon our plans will posted to this forum. They are becoming more and more concrete and I am starting to feel very good about them.
Brian Knight wrote:Well Doug, at least you didnt go so far as to say PAHS is largely proven. I standby my statement as largely un-proven. Perhaps the truth is somewhere in between but the lack of "proof" is discouraging to say the least.
Iam not asking for proof as I think that would be in the eye of the beholder. Still disappointed with the links and available info on PAHS projects. Ive tried several times but cannot access the yahoo groups posts. I would hope that there would be more data or information than a yahoo group discussion anyhow. Looking at the PACCS (PAHS?) link, the last post was almost 2 years ago and there is a serious lack of discussion and information for a building strategy that makes such bold claims or has so much potential.
I loved the terrafirmo link. This is similar to an underground home that I have brewing in my mind. Easily engineered and low labor costs. I would love to see more information on energy costs or temperature monitoring and can almost guaranty that the home would be performing better with insulation at the wall.
I want to make sure folks understand the difference between "underground building" and PAHS and the problems I have with the latter. Underground building does not equate to PAHS. To me the main difference is that PAHS does not insulate the below grade walls. This creates a heat sink and makes it more difficult to control the indoor air temperature. All the talk of temperatures evening out through the seasons is more hypothesis than theory. I go so far as to say it does not work. Insulation does work. Why go through so much expense and risk to try to prove otherwise with the results that are out there for review?
Brian Knight wrote:People should be aware that used windows might have low SHGC values due to the type of Low-E coatings typically used. This could make it less efficient than having no windows at all, even on the south.