<blockquote><cite>Posted By: wookey</cite>
Loading it in Openoffice, it is largely full of err:523 'does not converge', which appears to be due to the recursive definition in M3 =(M3+1)*O3
(03 is 1). I'm not sure what spreadsheets do with this sort of recursive function? Maybe I need to tell it to recurse harder?
</blockquote>
That M3+1 is just my iteration counter. Set O3 to zero, iterate once or twice, and the counter resets. Then O3 to 1 again. I don't know about OpenOffice (or anything else much to do with computers - this is almost my starting point) but maybe it is similar to excel where you have to tell it you want it to iterate, otherwise you get a load of warnings that 'there is a circular reference in the formula'. - and the iteration depends entirely on these.

<blockquote><cite>Posted By: wookey</cite>

Shouldn't the bottom row, which is the deep soil temp, come from $I$23 rather than just being '10'?</blockquote>

Well spotted. Actually I meant it to be $G$23, ie. copied and pasted from the G 'builders yard' column. Same result as plain 10 though. I'm impressed you could get this far in ten minutes. A lot more headscratching and pencil sucking would happen here.

The happy absence of macros is because at the time I didn't know what they were, but I do now. I use one to prevent the screen updating every iteration, which slows things down a lot. Another to make the chart. Hope this won't be a problem.

I think the answer has to be yes.

The thing to do would be to have your basement as an indoor swimming pool, hammam. Then circulate the water through solar panels in the roof. benefit from the thermal mass etc etc

I saw a programme the other day about female self builders here in France. One woman had done an incredible job refurbing an old farm house by herself over 10 years, room by room. She did an amazing job.

The crowning piece was a candle stick on the wall which when pulled caused the entire fire place to lift up reveiling steps down to a hammam in the basement. The hammam was stunning and done entirely by the woman.
Sounds a bit naff but it looked amazing, as if she had employed experts and paid a fortune.

Posted By: tonyThinking about my new house http://www.tonyshouse.info/ if the temperature under the basement floor is going to try to rise to the average temperature of the basement rooms then any help I can give to that process by feeding in surplus solar energy should reduce my heating needs. Yes?

Any news on how it's going, Tony? Do you have any means of measuring the amount of heat you're tucking away?

s&f -- temperatures were measured under my existing house -- sorry for confusion.

Search on web for thermocouples and data monitors, damp (humidity) measuring devices are a bit more expensive and physical sampling and weighing, drying and weighing again might prove more economical?

Keep up the good work...
J

Heat loss to the outside or into the basement do you think? Has the basement air temperature ever dropped below 15.7 ?

Hi Tony, has temperature under your basement dropped because of the recent heavy rain? The reason I ask is that I noticed our solid floor is cooler at one side of the house than the other by about 2 degrees C, and the only reason I can see is that the house is built on a hill with the cold side cut into the ground and the warm side being built up. The ground on the cold side is permanently wet at the moment and I suspect that water is flowing under the slab.

Thanks, Bri.

Thanks Tony. I know I have moving water in front and behind the house, so I think I must have it under the house too. I have no idea how to prove it and what to do about it though...

Had a look at my old simulations - sounds plausible, but... we don't know how much heat you've been able to put down there this last year, how much in 2010, or what air temp you have at basement floor level.

Resurrecting ancient thread FWIW.

I have been logging soil temp for over 3 yrs, at irregular & spontaneous periods, out of interest. Total of 64 datapoints. Have tried to graph them to best of my ability...

I have one sensor, one meter below the crawlspace floor, so 2.8 meters below natural ground level.

OBSERVATIONS:
Soil temp basically oscillates between 14°C in January and 17°C in August.
However, cold temperatures are trending up, and hot temperatures trending down.
Latter phenomenon seems to have been halted this year, with serious solar input.
Notwithstandng, it looks like the usual inversion is about to occur within next week or so...

Main Events:
. Fitted new (airtight/insulated) garage door June 2017.
. April to October 2019 : intermittent (chaotic...!) crawlspace heating trials using solar air.
. August 2019 : added DG patio doors to garage (which is main heat source at present).
. March 2020 : increased duct area and beefed up the load fans - began serious daily loading.
. Planning on integrating slate-hung facade as transpired solar collector ASAP

gg

Posted By: tonythis is more of a reflection of the temperatures in your crawl space

Cheers, Tony, I was hoping that that was the case !

What I also hope is that the inverse will eventually occur - viz. the soil temp will start affecting the CS temp!
In the sense that it gives UP heat rather than taking it away...

Posted By: tonyLooks like nighttime cooling might be a good move in the summer by adding fans and closable vents

Agreed - it's the CS that saves us in Summer -- it keeps our bedroom down to a livable temp, which was 23°C last week, while upstairs was over 26°C...

In winter, upstairs (living area) generally manages all day without any heating, and just a quick log-burn at night. However,the basement hangs around at 17°C and drains the house, that's why I want a warmer crawlspace !

gg