Sunday, 7 August 2022

a mnemonic for adjusting your watch (if it has a day date)

There is only one danger point and that is the period when the date is changing. Its typically between the 9 and 3 point on the dial. During this time:

  • do not wind the hands backwards when adjusting the time
  • do not adjust the date.

this is true even of analog quartz.You can find out if its set to AM or PM by pulling the crown out to the second dent (you may not feel the first) and winding it forwards and watching the date and observe when it changes according to the hour hand. This should be PM (because you want the date to change while sleeping and around midnight right?) The rule to uses is:

clockwise ... its wise to wind the hands only in the clockwise manner.



It really doesn't matter if you have a Quartz watch like this:


or an automatic like these:


it will have a mechanical system for clicking that day and date display over to the next day date. This is inside the old Sports 100 divers I have (which is a quartz watch).


Its not just my view either:



so be aware and don't fuck up your watch

Solar Floor heating house (again) position summary

So to complete this for a while here is a summary position of the improvements. 

Below is the data from what the house was like before I did anything, the data comes from a point in winter when I was away from the house all during the week (so no heating, just ambient).


Dear American audience, please note: as you (speaking of the General Public, not NASA or Science in the USA) are the living museum of discarded standards and practices in science (well and other things) these temperatures are in Celsius not Farrenhuffenfurter ...

Actual picture of Mr Farrenhuffenfurter the developer of the Eff temperature scale in 1724

So, today we have this measurement (photo of the screen of the temperature station cos I'm too slack to pull the data and compile as above). I chose to use the times above to match the 7:30am 24 hour slot taken here.


RED is inside, BLUE is outside (temps also in C not F)

Discussion

Firstly, what's truly amazing about this is that the area of "pipe" I have outside would suggest I can only capture (at most and assuming 100% efficiency) 500W of energy.

Outside temperature range is about similar to the graph from 2019, however its worth mentioning that the minimum outside temperature today is a little above what it should be because I'm hanging the thermometer under a tree now. The actual outside temp this morning was -0.5C (with a frost). The inside temperature goes into the night warmer (being nicely heated by the solar floor system and its attendant insulation). 

I did use a bit of reverse cycle AC in the morning (evident from the step up in the curve) and a fire was use in the evening (again evident on the graph).

Insulation fitment in both the ceiling and the floor was critical to the success of this project and it has not only enabled the (quite meagre) energy available from the outside solar to be transferred successfully into the house.  Further the insulation has meant that any heating I do inside the insulation (where I live) is far more effective.

Outcome

My house is now much more comfortable and my heating costs (electricity and wood) are significantly down (approximately 25% of what they were). If you dont' give a shit about environmental issues you may give a shit about your finances ... so its either win or win win (depending on your value sets)

If you have landed here and are unaware of the history of this project you can find it at these links:

  1. Solar floor heating again
  2. part 2
  3. when the sun don't shine
Naturally as a perpetual tinkerer this will change and improve as I tidy up all the insulation sealing and and consider other Solar Heat Gathering methods.


... There are very few nations in the world that use this unit of temperature. The countries and territories that use the Fahrenheit scale are the United States, the Bahamas, the Cayman Islands, Liberia, Palau, the Federated States of Micronesia, and the Marshall Islands.

I think thats hilarious. I wonder ... can the USA ever modernise? 

Saturday, 6 August 2022

Floor heating when the sun don't shine

It can't only be Solar

As per my previous attempt at this 10 (or so) years ago there are times when you can't use Solar (not least because we have nigh as well as day) such as when its rainy or overcast. So in anticipation of this I wanted  to prepare a different solution to last time (which I used LP gas) that might be cheaper.

Ad mentioned in my previous post I thought I'd try this:


which is a 1000W aquarium heater (electronically themo-regulated).

So 1000W (if you think heaters) isn't likely to heat your house by itself (unless you have a small and very well insulated house) but it can bring something to the party. 

Yesterday I ran the system and recorded the following data


RED = interior GREEN = under floor BLUE = outside

So lets look at the points:
  1. turned on the reverse cycle AC to heat and set that to 20C
  2. the floor pumps turned on and started pumping (which meant that the heater started having to heat the water because cooler water was flowing into the junction tank from the now cooler floor)
  3. I lit a fire because I wanted to spend time in the living room (and the floor pumps had just stopped as they are on a timer).
  4. note the change in slope on the red (the interior) curve as it fell and eventually became the same slope as the floor. 
The final red line is when the fire went out. Now when I went to bed I set the AC back down to 16C  (and it had ceased providing heat after I lit the fire) and the house now started to cool relying only on its insulation and the AC to keep its heat.

I woke at about 5:30am (pretty usual) and noted that the AC was making some gentle stirrings as the house temp fell into the zone where it was kicking in. This means that basically the house kept its heat sufficiently just on thermal insulation alone. Not bad.

Lastly there is the slope on the red and green curves. Some things I anticipate at work here are: the higher the difference in temperature (between inside and outside) the faster the rate of loss. Then as the interior reaches about the same delta T as the floor then the thermal mass of the floor (recalling its on the inside of that layer of insulation) works to hold the whole system higher. Eventually they'll fall together at the same rate as the difference diminishes. I've seen this in other plots.

Some Further Notes 

Power consumption: The setting on the thermostat on the water tank heater is 20C but I've observed that when you use a quality thermometer to measure the water temperature in the tank its 18C when it thinks its 20C (who'd have though, its not a calibrated scientific instrument?). This is interesting because the floor temperature reading (from between the insulation and the floor boards) was almost that. So the floor reached an equilibrium temperature within 3 hours and stayed there (just as the room temperature did) for 8 hours. This despite a falling of outside temperature during that time (so yes during the day).

I have a watt meter on the tank heater and it showed that the heater only consumed 1.2kWh during the day and 1.5kWh 24 hour period (yes, including keeping the tank warm all night). 

This clearly shows the benefits of the insulation (at reducing losses) and the benefits of a more modern and efficient approach to heating (reverse cycle AC).

Other benefits: without heating the floor there are many problems with using the AC to heat the house. For instance it only heats by moving warm air and so does not directly heat the floor, far down the walls, under beds or other rooms. Sure some radiation from the ceiling eventually warms the floor, but by heating the floor directly you gain this benefit this heat coming through the actual floor boards and into the carpets and under beds ...

Basically this makes the floor boards into a thermal mass for storing some of that heat after it ends and because its on "our side" of the insulation barrier keeps our space warmer longer. Evidenced by that slow trail-off of temperature.

Where to next?

We are moving out of winter and into Spring now, but we are slated for some 0C temps next week. I'll be interested to post on the results for that then. 

I'm thinking about if a better area of Solar Collection will help, but frankly I'm not entirely sure it will. This winter has been significantly more wet and overcast than previous years, so it will remain to be seen how this impacts the generation of warmth inside the house. My current area of collector is about 0.4 square meters, this suggests that I can only capture at most 100W of energy from that. So it may be worth increasing that area. Knowing that answer will require an experiment to find out.

So, as always, further research is needed. 

Friday, 5 August 2022

Solar floor heating again (part 2)

After some interesting delays created by life involvement (and not least frustrating injuries) I've now just about completed this project and its in what I'll call the tuning phase. Back in this post (part 1, so yes 4 yeas ago) I showed the laying of the pipes (and man wasn't that some hard work) and discussed the insulation and its role in making this effective.

underfloor insulation

This has a critical role in the success of the system because it confines the heat in the pipes to be all released into the floor above the insulation (and not just carried away by the breeze or radiated into the ground. Recalling from that above mentioned post this is a sample of how I run the pipes under the floor:


and now the insulation holds that heat in as well as drastically reduces any losses from the house through the floor too. This last point is not insignificant.

So to recap the design idea, water is circulated through the (four) floor circuits (each of the above pairs of pipes flows in opposite directions, see the previous article) and out into the yard where it flows through a pipe in the sun to get warmed then back into the floor. This is done with what I call the junction box where water being circulated through the floor goes back into the junction box and meets the water being circulated through the yard in the sun. Because its a syphon arrangement (again, see the previous articles) the requirement for pump "head" is not significant and flow rate is the issue.

So lets have a look at those components. 

Junction Box showing flor circuits and outside circulation (on the left)


the pumps:


and you may have noticed in the above shot over on the left a small black thing, which is this:


A 1000W aquarium heater (themo regulated) which I'll go into later.

How it works:

Basically the design is to take heat that exists outside of the house during the day (especially when the sun is shining) and pump that through the insulation and into the house. Especially in this environment the insulation plays a critical role because if the heat losses are higher than the heat inputs then there will be no effective gain. 

Lets look at those gains, this is a picture of my 3 channel temperature recording station; the three channels are:
RED = inside the house 
GREEN = under the floor (outside the house) and 
BLUE = outside temperature (away from the house).


You can see that inside varies wildly because I heat the house in the day and then turn off the heating when I go to bed (to save money among other reasons) and begin heating in the morning.  The green line in these pictures closely tracks the outside temperature (and you'd be right in guessing my floors are cold underfoot!) which turns out to be an interesting metric (which I'll get to next)

This identifies my goal: to flatten that inside temperature curve and with less expense.

This above image is a snapshot of the 72 hours preceding my placing most of the insulation in the floor (the spike is me handling the thermometer and repositioning it so that that it wasn't trapped between the insulation and the floor forever). Note date's and times in the images.

Quite an impressive result immediately and shows clearly how much heat was radiating out of the house through the floor and out into the world (now trapped by the insulation layer under the floor)... wow.

Indeed this next image shows how now the floor tracks the inside of the house not the outside anymore (note the timebase change on the X axis to zoom in more on the 12 hour period).


again, wow.

The next phase was to then plumb up and turn on the floor heating pumps to transfer energy inside the next day and see what's happened to the floor temperature and test the system (oh, and btw, by this point the floor insulation is not 100% complete, more like 70%)


so above you can see how the house is dragged up now with the warmth of the day, and the floor heating, where I lit the fire (wood burning stove heating which explains why above I mention I don't heat at night after I go to bed), how that as the fire went out the temperature of the house fell down to the floor level and stayed on track until eventually (after this time stamp of 6:55am) the sun came up and things rose again.

Because this is an experiment in progress (still learning about how to tune this in this environment) I ran a few scenarios lets look at the outcomes from them.


Scenario 1 = increase the Junction box (water tank) temperature with the heater to put in (up to) 1000W of energy (as determined by the heater system) by setting the thermostat to 20C and continuing to run the floor pumps all night. Note: some heating with AC during the day and a fire at night. Note 2 we don't have a plot of the water temperature here.

Scenario 2 = passive heating only inside (red curve) but running the floor pumps (note: I am continuing to fit out the floor insulation during this)

Scenario 3 = fully passive with no additional energy added except solar through the heat pump, no aquarium heater (more of the insulation  fitted, nearing 100%).

Discussion

The basic tenet of my process has been to harvest energy when its there, and store it for when it goes away. This is basically energy from the Sun (and when its all said and done what isn't {ans Nuclear}). I havest this in two ways:

  1. capturing heat from the sun and shoving it into my house as thermal mass and using insulation to reduce the losses (think water in a bucket instead of just held in your cupped hands)
  2. using the outside heat to make reverse cycle AC more efficient (it works on the temperature differential you are facing; there is a hot side and a cold side. The warmer the cold side is the hotter it makes the hot side, the reverse is also true) and thus use less energy
The insulation (also put into the ceiling late last year) massively reduced the losses at night (convection within the room as hot air rose to heat the ceiling and shed it fast without the insulation and radiation losses too) and now this insulation on the floor reduces the losses through the floor from radiation too as well as enabling me to capture the 1000W of heat available per square meter in the sunshine.

I have now cut my wood and energy needs to heat in winter by 75% and have a warmer and more consistently warm house to boot.

Not bad if you ask me ... 

Costs?

The entire costs (ceiling insulation, floor insulation, pipes, pumps and fittings) has been under AU$1500. 

I chose polystyrene because it has both a better R-Value than the messy and horrible mineral glass wool, and unlike that product does not lose its insulation property over the years NOR does it breakdown into a filthy difficult mess in 15 years time; and bonus points for it not being enjoyed by rats or other pests (who love to nest in your ceiling insulation).

Win Win