I lurked here for quite a while before registering. I like to know something about the people I deal with on forums, so here goes about us. I have given links to the websites of our “team” so you can use the info to learn more about us and the project site – my webpage shows some useful photos, particularly via Google maps to better understand my descriptions below. If you do access my site please ignore the sales part, I do not want my first post to be my last. It is a long post, but necessary to give the full info.
I live a few miles from the city of Castelo Branco in central inland Portugal and farm full time. I am an old peasant who has farmed in four different countries over six decades so have picked up a bit of experience and some ideas. I also claim to be well educated - a Bachelor of Business majoring in law and accountancy so I understand the written word and can crunch numbers – http://www.oldmcdonaldsolives.com My son has two Masters and a PhD in astrophysics disciplines and works in astrophysics, so he understands all the equations and obviously has an in depth knowledge of the sun/earth relationship - http://www.jb.man.ac.uk/~mcdonald/ He is the only one of us to have visited the U.S.; giving a short series of talks at Cornell, Harvard, and NASA Washington and Baltimore in 2012. My friend Patrick has a quinta (Portuguese for small farm) about 4 miles away, but is in an earlier stage of the development of his place than I am, and is only here part of the time. He has an excellent knowledge of just about most things electronic and mechanical plus experience of using solar applications. His website is currently offline whilst he revamps it.
The project is not imminent as I have others to complete, but I also like to plan ahead and the idea is to provide underfloor warming to the living area of the house. Not necessarily full heat, but enough to warm the floor slightly. Some heating is needed for up to 7 months of the year and cooling for up to 4. Both can be less but there is very little spring and autumn weather. We presently use a wood burning stove in the room used most - a typical farmhouse kitchen/dining/living room, plus have reverse cycle air con (mini splits in US?) in all rooms and sundry electric heaters for use when necessary.
The house has a footprint of 135sq m/1350 sq ft; is on three levels with the unfinished top level presently used for storage, although it could provide more bedrooms. The living area is the middle level – ground level at the front and one storey up at the back. The bottom level is partially underground in the style of southern European cellars and protected storages. That is in three separate rooms – an olive store (for equipment and olives) is half the area and a winery/wine cellar takes up most of the rest, with a cheese store the balance.
The ceilings of the bottom level are the floor of the living area. These ceilings are 12 feet and they are almost entirely clear of any obstructions. Long term I had envisaged a system involving water storage and heat transfer, pumping to pipes across the whole of the area (divided into runs) but initially as a trial I would like to try direct pumping from a collector to the ceiling of the olive store to see what sort of gain we can achieve. If it is particularly successful I would set up the same for the rest of the house instead of a water storage system. In winter these cellars at floor and mid height are usually equal to or one degree above unheated rooms in the house averaging around about 12C or low 50sF.
In times past olives were stored under water in brick cement rendered bins and there are 3 in line of 2 cu m (just over 500 U.S. gallons) each. These days small boxes are used during olive harvest and transported more frequently to the buyer, so the bins are no longer required for their original purpose. There is also a lagar (a tank where the grapes are stomped) in the winery/wine cellar, also no longer used, and just over 3 cu m. The wine cellaring part is most definitely used!! So plenty of already built thermal water storage volume if I need it. I could have two systems – one for the living space above the olive store and one for the remainder. Water storage is easily increased by making the walls higher.
The whole house is stone, concrete and brick. Way back it was an olive mill. The ceiling is 18 to 20 cms thick, as near as I can measure, so an enormous thermal mass. Concrete beams in the shape of an inverted T carry specially shaped honeycombed bricks. The beams and bricks are topped by a cement screed and tiles. The ceiling of the living area is of similar construction.
Whatever I do it will not involve any internal disruption to the living area. All rooms have tiled floors and some either partially or totally tiled walls. As an initial experiment I would like to try direct pumping in a closed loop from a collector to heat pipes with aluminium spreader plates attached to the concrete beams in the ceiling of the olive store.
We know there is a long way for the heat to travel before it reaches the tiles, but provided some heat travels upwards it will eventually reach the floor of the living area, dissipating to some extent sideways before doing so. The length of time this takes is unimportant, and anything is better than nothing.
The depth of insulation below the pipes can be anything I choose given the high ceiling height, so heat loss downwards can be minimised, but insulation is not a strong point in Portugal. 30mm sheets of Wallmate are available locally, and not much else, but I will be looking further afield. DIY in general seems not to be a way to spend time, and sourcing supplies for many jobs is difficult. Sand, aggregate, cement, concrete beams and all sorts of bricks are easy, but apart from a few pv panels and domestic HWS there is not much evidence of solar. Wind is the main source for grid supplies of electricity.
I have kept weather records for the 13 years I have been here. Temperatures rarely drop below freezing, and then only by a couple of degrees on clear winter nights. We can go through a winter without a frost. Year round I wear only a short sleeved cotton shirt both indoors and out, no undershirt, no jumper, no jacket. At times indoors we have the common complaint of being hot from the knees up, and cold feet. 20ºC/68F is plenty warm enough for my wife and me in the main living rooms, and a few degrees less in our bedroom/bathroom - above the wine cellar. Our winter comfort (at least above knee height) is easily achieved with the woodburner and electricity, but I want to use solar.
Any fog lifts early in the morning and it is unusual not to get some sunshine in the day, with many days of all day sunshine throughout winter. I am more or less unlimited with space for collectors. As can be seen from the Google Maps link on my website (the olive store is on the north end of the building) the house is orientated so that collectors against the wall, or garden walls adjoining the house, would catch sun from mid morning and face directly into the afternoon mid winter sun. A street view from across the river shows the back of the house. A linked collector (possibly batch) could also be placed to catch the morning and early afternoon sun, being shaded by late afternoon.
I have spent a lot of time over a few months reading the info on this site, Build It Solar and anything else I have been able to find, and I am very grateful to you all for many hours of informative and enjoyable reading. This forum is outstanding, but there is only a little info about direct pumping. I suppose it is not a common practice in places with cold winters. Thanks to the immense amount of info on here and BIS I do not have any questions at this stage. I will have later, but for now please feel free to comment upon or condemn my ideas.