Andrew Welser

I've been designing an earth-sheltered home in my head, I don't have land yet to actually build anything. I'm in Texas so there's a greater need for cooling, but still some need of heating; I am leaning towards piping in the floor and/or ceiling for radiant heating and cooling, with large insulated hot and cold water storage/buffer tanks. This would allow multiple sources of heating/cooling (separate dehumidification would be required, and to prevent sweating the cooling water in the radiant system would need to be kept above the dewpoint temperature). I'm also considering the use of phase-change materials in the storage tanks to increase the amount of BTUs that can be stored.

My hope is the earth sheltering and PAHS (passive annual heat storage - see book by John Hait) would cover the majority of the heating/cooling needs, but secondary/supplementary options I'm considering using for creating hot & cold water for the radiant system include the following:
--Rocket wood fired water heater
--Heat Pumps:
   --Water-to-water: pull heat from the cold storage tank into the hot storage tank
   --Air-to-water: heat or cool one tank when the other is already at temperature
   --Water-to-water: heat or cool individual tank same as above, but pulling/dumping heat to/from a pond and/or underground piping (i.e. ground-source/geothermal heat pump)
--Propane on demand water heater
--Solar hot water panels
--Radiant cooling water panels
--Heat pipes between the outside air and the storage tanks

When I was driving truck locally a number of years back, I first got tired of hoping I could schedule my drive time to make it back to the terminal for lunch time to use the microwave, so I packed food I could eat on the road then quickly got tired of sandwiches. I bought a 12volt food warmer from Amazon (not that particular model, just as an example), and some glass food storage containers. I could pack whatever leftovers, put them in the warmer and plug it in about an hour before I planned to stop for lunch, and have a hot meal wherever I stopped. After maybe 6 months the first one I bought stopped heating, but the convenience was so good it was worth buying another one. If I wasn't working where I'mclose enough to go home at lunch I'd definitely consider one of the 120V versions to minimize my microwave usage.

There are a number of things I'll do to try to minimize vibrations and resonance of the material being cut, some work better than others depending on what I'm cutting:

-Clamp/hold down more tightly the thing being cut.

-Change the angle of the blade relative to the material being cut.

-Press the blade shoe (for lack of a better term) of the saw against the thing being cut: most blades cut on the pull.

-If it's a variable speed saw, try different blade speeds to find one that minimizes resonance of the material being cut.

-Vary the pressure applied on the blade.

-Especially if the thing being cut is unsupportable, and/or floppy, take weight off the saw blade, get it "up to speed", then slowly allow it to start cutting.

-Use a blade with finer/less aggressive teeth (more per inch).

-Find a blade with wider teeth set to be sure the blade isn't binding in the cut. (had this problem with some cheap pruning blades I got off Amazon: almost no tooth set, so the body of the blade drags in the cut, making them almost unusable)

As an HVAC tech who has worked with ground-source heat pumps, I see some potential, but let me also give you some points to ponder:

For a closed loop liquid ground-source system, I see design numbers in the range of 300-500+ feet of heat exchange pipe in the ground per ton of AC/heating. Heat moves relatively slowly through earth, so if the volume where you're pulling/dumping heat is too small, by seasons end you'll have a too high/low earth temperature and lose efficiency, or even not be able to run the unit if temps get too extreme.

This seems like an easy situation to get in if you're pulling air from the sewer, the main air source is likely to be your neighbors' vent stacks (assuming you can pull air from your sewer line, and still let your sewage through without pulling air from your own vent stacks), so your effective pipe in the ground distance will be the length of yours and your closest neighbors' sewer feeds plus the distance between feeds of the main sewer line. This has the potential to work, especially if you have some distance the air has to travel down the main sewer line (i.e. not another sewer feed just across from yours). The "fresh" water flowing down the line will greatly expand how much heat you can pull/dump.

That is the big issue I see with using a septic tank: the relatively small volume around the tank, and the relatively small inlet of "fresh" water seems to me to be way too small a source for household heating/cooling. A ton of AC capacity is called that because it's equivalent to the heat absorbed by melting 1 ton of ice in a 24hr period, and (at least here in Texas) a household AC system is often 2-4 tons (and similar sizing is needed for heating). You'd have to calculate the water flow going into the septic system and if you have enough flow to dump/extract heat with a reasonable temperature drop/rise. If not, in a very short time of heating a house in winter weather, the septic system might become a block of ice!

(To do the above calculation a ton of AC capacity is 12,000 BTU's/Hour; the definition of a BTU (British Thermal Unit) is the amount of heat needed to raise 1 pound of water by 1 Deg F).

Another potential issue I see is flowing enough air through the bottleneck of piping designed only to flow water/sewage.

The best option would be getting a heat exchanger in the main sewer line of the neighborhood. The decently large non-recirculating flow of water would be ideal for pulling/dumping heat. A pump and dump ground-source system usually involves multiple gallons per minute of water flow through the heat pump, often sourced from a well; waste water would be a much more sustainable source.

A little like the opposite of "White Coat Syndrome".

I've had similar things happen before, the most recent occurrence was attempting to set up filters on a Google Sheet of Form responses: I was having trouble getting it to do what I wanted, so I sent off an email to a co-worker asking if they could help or knew someone who could. After sending the email I kept googling and trying things, and finally got it responding how I wanted. I hadn't gotten a reply from him yet, so I got to send another email saying "never mind, I got it figured out!" I'm sure I'd have figured it out eventually even if I hadn't emailed, but it felt like asking for help (even without receiving any) was a necessary step in getting it to work!

John F Dean wrote:If you are in a difficult situation and one door closes while another door opens  … your house is probably haunted.

When one door closes, another door opens...

Other than that, it's a pretty good car!

John F Dean wrote:About 50% of the times when “Be careful” is used.  I noticed it earlier this week when I stumbled on something. Someone uttered the phrase after I stumbled.  It would have been far more helpful if they said it beforehand.

When someone would trip or bump against something, a friend would usually say "They just put that there."

He also would often say, when someone would use a 'royal we', "We? Do you have a mouse in your pocket?"

Here in Texas, it's not uncommon to hear/use 'fixing' used in place of going or preparing: I.E. "I'm fixing to go to town."

Gary Numan wrote:"What’s your snow removal strategy?"

April.

I live in Texas (for a reason!) so my strategy is wait a week! AKA:

Deane Adams wrote:My current philosophy, at this stage of life;  I didn't make that mess, I'm not cleaning it up !!!

Andy Ze wrote:Although I haven't seen anybody microwave it yet.

I'll keep leftover coffee in the fridge and microwave it to heat it up in the morning. But to actually make coffee, I'll usually use an electric kettle and french press.

If you need to do "truck things" often, &/or need 4x4 then a small truck makes sense, but if, like me you aren't hauling the majority of the time, may I recommend a hatchback, station wagon, or minivan (much better interior space for hauling vs a sedan) and a trailer. If you need the 4x4 traction you could go with a smaller SUV and a trailer. You want something big enough to handle your normal loads (inside and on a trailer) but no bigger than necessary to minimize fuel usage; rent/borrow for the occasional large load outliers. Or you could have multiple vehicles with different purposes: something small that sips fuel for daily commuting and a larger truck/SUV for occasional hauling.

I'm also partial to Toyota reliability and manual transmissions.