Okay getting back to this. I see I missed number 4 and I will add number 5 as well.
4. I would NEVER do another house with windows/ventilation in just one wall. There is no cross flow capability for cooling. Now the light isn't really needed and there is almost nothing to see out a window if I retrofitted in to the wood frame triangle above the east or the west concrete wall. So most likely I would go with a tightly sealing hatch of some form. Now because the high part of the north concrete wall is my primary heat storage I would not put windows in it up high. But because buttress walls are needed in that long of a concrete wall either inside or outside I have wondered about doing vent doors in the basement and just doing a really deep window well between 2 buttress walls.
5. Missed in my first thinking. I would never do another house of any kind without a plastic swedish skirt around the perimeter to move in ground water out away from the building 4 to 8 feet. Thus it would go a short distance up and under the siding and down say 18 inches to 2 feet in the dirt and the slope steeply away from the building so water that in the surface dirt was moved away from the house Now something learned watching the dirt here is that even well packed dirt settles. So I would plan a 1 foot or greater pleat (giving 2 feet as it unfolded) so the plastic went down from the siding, folded back to the wall and then folded back down deeper. To hold it in place while getting it buried I would put a strip of card board in the full height of the pleat and glue it to the back plastic.
Now to actually answer the question. It is worded wrong. It should read "can they" and the answer is a most definite yes. They come with some inherient advantages and some inherient disadvantages. Whether they help or not is a matter of good design and good construction. That said they are not necessary for it to work. This house works on 4 things, Solar gain, air tightness, thermal mass and insulation. Any well designed and built home can have those traits without being buried in the slightest. Especially with modern building materials.
Now to stay truly comfortable this house has historically had both heating and cooling. But I fairly sure both can mostly or totally be eliminated cost effectively even retrofitting. And if things were built in from the beginning it would be better still.
First lets look at what is here. By 1984 standards the house was say over built but by modern codes for this area the walls need another inch of insulation minimum and ideally at least 3. The roof needs another 2 inches to minimum. Modern code would like another at least 6 inches and ideally more. It has been heated with a nearly 100 year old free standing propane room heater. No winter humidity problems while the heater is running as it exhausts enough air to prevent problems. Now the house is so tight that to run the clothes drier, a door or window must be opened to prevent it from back drafting either the heater or the water heater. Not a problem in summer as the house always has something open 6 to 8 months of the year. Since I have been running without heat I do have a winter humidity problem. Planned solution for winter is adding a solar thermal powered HRV core to both exchange air and preheat the incoming air solidly. Hopefully unpowered but only needing low power fans worst case. Summer air conditioning one 18,000 BTU window air conditioner mostly worked well enough. During really bad heat runs or while canning hard it was marginal. That is the largest 110 volt window air conditioner sold. But that was doing whole house. But it was mounted in the worst possible location so probably it would have been doing enough it if had been mounted in the shade rather than in the middle of a hot brown wall on the sunny side.
A. So lets start with humidity control other answers.
First is ERV cores. They let you pull fresh air in without pulling all the humidity with it from outside. They will keep about 50% of the humidty out or in where there is a difference.
Now for simply exhausting where there is a difference the HRV cores will work. This is my plan to solve this for winter use. Pull the air in up by the underside of the roof overhang 15 to 17 feet in the air. Down around the window area and on down between the back wall of the collector and the house wall. At the bottom take that air up thru the HRV core to transfer most of the outbound heat to the fresh air. (typically rated at about 80%) From there the air rises thru 14 feet of 4 foot wide collector and back in the awning style window into the master bedroom. The other half of the air circuit will pull off the floor in the basement at the lowest point and up to the outside wall. It will take the air out thru the wall(only major house modification in this about 2 feet above ground level and into the other side of the HRV system. The air will flow down thru the core towards the ground and then run sideways to another collector built from a large commercial glass door. It will be heated there an chimney up to be exhausted at the top of the door. Thus I will have both thermally driven suck and blow pushing on the HRV core. Hoping this will work without fans but planning fan locations in the design just in case.
As for summer humidity control this is a desiccant driven air conditioner that looks like a good answer for summer time use.
Now I don't think this will be needed in my location but I plan to do the bare minimum to implement it if needed. The neat thing is here that it has some possible synergies that would reduce complexity while giving more performance.
The final output stage evaporative cooling here what if we dumped that heat into a hot water tank first and then into a geothermal loop for cooling. That would eliminate one fan and on pump from this system while helping to heat hot water for household use and potentially dump heat in the ground for help with annualized geothermal for winter time heating.
B. Now that brings us to the air conditioning thing. The primary think here is simple geothermal cooling with possibly reservior cooling and the above desiccant cooling added on. Guessing if I had the addition current code recommendation I would need far less cooling but remember I am retrofitting.
Here is the link to a good video on the geothermal cooling.
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Now if you look at the various people's answer for how much is needed and the answer for range from needing 400 to 900 feet of piping to get the 18,000 BTU. Now burying that much pipe retrofit is a lot of dirt to move. But in new construction can you take advantage of existing dirt already moved to reduce cost and effort. My thinking is a zone under the basement floor. 3 zones ideally in concentric shells using dirt distance and reduce delta T so hopefully some of the summer cooling becomes winter heating. Then when the dirt is all dug up add a set of loops for the brine line cooling for the desiccant AC if need. So I am thinking potentially 4 zones on this. For new construction what if you took advantage of existing dirt work. Say you have a basement that is 1000 square feet and its dirt wall to provide work room are 4 feet larger each way. Now you are a perimeter of nearly 160 feet. So 2 loops around your basement hole would give you 300+ feet of line and 6 to 8 feet of depth without doing anything other than installing the line. Do you have a water line trench or a septic trench that is fairly deep. More line down those?
The other half of this is how to transfer heat from the house. I want to do a fudged version of radiant ceiling. Instead of the radiator mentioned above I am thinking loops of pex up in the high point of the ceiling. 3 loops of pex for say 360 feet of ceiling pipe gives the same surface area as a 2" thick 2'x2' radiator at 10 fins to the inch. The hope is that by doing that in open free air I can get it to convect without a fan. Now in winter if I can get the house too warm with solar this will let me cheaply air condition the house. It will also sort of store heat so if the house starts to get cold I have an earth battery to tap for heat with for only the cost of running the pumps. My soil temperature is roughly 56 degrees so if I can store 5 or 10 degrees of heat on days the house over heats in winter now I am looking at that potentially as the coldest the house can get just by circulating water. Now the advantage of doing water instead of earth tubes is no mold in the air and pipe is smaller so slightly lower cost per foot. Disadvantage is 2 heat transfers instead of 1 so lower efficiency and fans cost less and are cheaper to run energy wise than pumps.
I see one other option to either add or to substitute here for just cooling. I have a reservior that I pump out of fairly steady in the heat to irrigate garden lawn, trees etc. What if I can shave heat off with that as more loops up high in the house. The water going to the plants will be slightly warmer but that is all. I already pay to run that pump and my lose would be say 120 feet of head for 3 parallel loops which if it matches 120 feet of 3/4" garden hose would not be that bad..
And of course the final piece if needed would be the desiccant system above. It would need a brine line also buried in the planning and some planning for line exits and entries into the house. But if not needed this would be the only real lost costs as all of the rest could be added later if you found you needed them without much additional effort.
C. Now for the heating. If I was building a new I would be going for passive solar primarily and actually building for a bit more gain than the books recommend under the theory that I could cool it away as needed. I am already a bit over and find the interior air circulation system helps moderate to the concrete of the basement.
Beyond that if building new I would go with with mostly strictly water solar thermal systems.
Here is the dream system. I would say everyone in heating climates building new should at least look at it and think about it. It has some other possible simplifications and I will post videos for those too. The neat thing is this used properly can potentially give heating, hot water and air conditioning all in the same system. As he points out while there is added cost if you can get rid of the water heat, furnace and AC you have all of that to spend on this and you probably come out ahead.
Now for retrofits I got stuck on the word tank. Here is a smaller storage that would do the same thing on a smaller scale.
Now how to simplify. Here is a video on drain back system. Combine it with multiple stratifiers for each individual circuit from the above and you should be able to build about the simplest system possible. Here is the drain back system which eliminates need for a bunch of complexity
Now I wish to add 2 small changes to it to reduce water vapor breathed into the room turn the drain back on and off. Floats and a diaphragm over most of the top of the tank so dry air is what comes out of that area. And the other area of the top of the tank a water based cooling breather from alcohol distillation.
Now air based collectors are a third system to look at. They are simple to build, can be really efficient and fans are cheaper than pumps. Leaks very rarely threaten a building too. The are also more retrofit friendly where you have enough mass already in the building inside the insulation. Now their key feature is the ability to choose whether you bring that heat in or simply let it vent right in place. Link to my write up in the previous post.
Now one other thing that should be mentioned is folded path collectors. While they are more complicated to build I think they can do away with needing doors etc for the system to not lose heat badly at night. Here is link to one of the better write ups on this. Notice this web site is no longer up so this uses the internet way back machine site to access. Still room for improvement but good write up.
folded path air thermal collector
Now why would we want solar thermal over PV? Biggest is that it is 3X to 4X more effiecient. It is panels things that are quasi DYI friendly. It can mostly be built from salvaged material
If you are going to do in ground suggest looking at elastomeric coatings for concrete, various densifiers and silanes to protect the concrete and block air and moisture. Adding plastic barriers or pond liners for radon and water protection. Looking at drainage systems to keep the water away from walls. Now I will say the concrete walls upstairs here look really good. We ground the high spots off and filled small pores etc in the concrete with drywall compound and painted. It has been very durable and looks like normal walls. Basically the sun is shining right on the concrete with only paint interfering in most locations for heat storage. Now the one complaint is hanging stuff on the walls as that take drilling holes in concrete which is a bit of a pain. And we have 3 outlet location mistakes literally cast in concrete even with very careful planning. One came loose from the forms and moved, one was a bad measurement transfer(as the plans were correct) and the final one was a mistake in our thinking. Blower door scores for air tightness matter. You can always add HRV systems or designed air leaks to a tight house but it is tough to fix if you built poorly to begin with and have too many leaks. And finally meet at least your areas minimum insulation standards.
I will say again while earth homes of various forms can work well it is NOT necessary for them to exist. Normal construction methods done well in a free standing home will work too.
And then I will add one lesson from the tomato float. Even below ground rated foam can become water logged and hard to dry out if it doesn't have good drainage. So be sure you do not trap water against it long term. It took a year out of the water to dry it out and it is more porous after.
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