SteamyTea

Would you have to be concerned with flow rates in the summer? I often wonder how well balanced a system is after a few weeks of operation.

Does it have beer and kebab stains on it

Can't you just stick a cheap portable aircon unit onto the MVHR inlet to the rooms.

Ohms law will tell you what you can do.

Yes, if anything it could run the pool too hot. I only had a manual OnOff switch on the pump. There is a big difference in running up to 28-30°C for a swimming pool and getting up over 50°C if you want to rely on it for DHW. Easy method for cheap pre-heating when the conditions are right. I used some cheap agricultural semi-rigid black water pipe laid on a gravel bed, then poured dyed concrete on top. If I was doing it again I would put some insulation down instead of gravel. And make a control system.

Not unusual to get the best relative performance this time of year because of the combination of temperature and array angles.

Isn't it Wh?

You're alright, they call it thermal storage. I made a similar system for a swimming pool back in 1984.

How did we end up with terraced houses laid out the way they are? If we turned them 90°, living room to one side, kitchen the other side, stairs in the middle, would they take up more land area in practice. If, say we are trying to build houses with a 5m by 10m footprint, a garden area that is the same, a road/footpath is 6m wide and a parking area at least 4m by 8m (just guessing at these figures) and the total development area is 100m by 100m (a hectare). A traditional terrace would take up a total land area of 155m2, while the 'turned 90°' would take up 170m2, so on a 10,000m2 square development, you would get 65 homes or 59 homes respectively. You would get more 'parking' area with the 'turned 90°' housing, but not enough to get two cars in, and it would probably be wise to put in some alleyway access on the traditional housing, so it would probably even out. All this does depend on having the ideal site to develop, but as England has 130,27,900 hectares of land, this cartoon development is only 0.000008% of the countries total area and about 0.00008% of the urbanised land area (of in other words, f all) Is 5m enough to put a staircase? I know that my 3.5m isn't.

Many people have low expectations of housing and think that what is on offer is the best they will get. Can you put the main door into the kitchen? That does depend on orientation. My car parking is at the back of the house, so the back door is the main door. The main door does have a porch, so not too bad, though hardly gets used.

I am not sure I understand what you mean here. I live in small a 2 bed terrace. It is dreadful. The living room is just a corridor. I think a terrace needs to be 5m wide, that way the stairs can run across the house, this would separate the living room from the rest of the house. The same could happen upstairs, separating the master bedroom from the rest. Ensuite under the stairs if there is a second story. With terraces, orientation is everything. Mine is NE (rear) SW (front). I get no decent sun in the afternoon at the rear (the garden, and f'all grows well there), the front is no good for sitting out on as it is by a road. There is little opportunity for PV as well. The really sad thing is that with a bit of thought, the whole development could have been so much better (there is more car parking than housing area).

I think the basic concept is that any module that is not working at the optimal performance for the conditions i.e. shading, is bypassed. This stops the module being heated up by the other modules i.e. self consumption. This can cause a power drop for the whole system. Micro inverters do the same thing and convert the wild DC current and voltage to regulated AC. If you don't have a shading issue (or only a minor one), there is nothing to be gained by using individual module optimisation. Let a normal inverter deal with it.

Wash them when it is raining, that should rinse them off a bit more.

Friend of mine was on Customer Servies at Sainsbury, she had someone bring back a toilet roll that was miss wound (you know the ones, you get 1 ply and your finger pokes through). Not only did they have to refund the multipack, they paid her taxi fare as well. I think they changed policy after that, as when I took some oranges I bought the night before back (they had gone mouldy), it took 20 minutes to get my £1.69 back. Hardly ever shopped at Sainsbury since.

Would that not 'wash' the house downstream as well? I think that the Earth emits 62.5 mW/m2 on average, not a great deal. Lord Kelvin (of should that be Lord K°, real name was William Thomson), used this figure to calculate the age of the Earth, but he was unaware of radioactive decay when he said it. Ernest Rutherford put him right 1904. Rutherford showed that 1 gram of pure radium releases enough energy to raise 1.3g of water by 100 K (though probably called °C then) in 1 hour.

We have had a couple of architects on here, one does not seem to post anymore and the other only lasted a few days. This is a shame as we cannot 'educate' them. I think part of the problem is that people have a mental image of an architect, and that is generally based on well known ones (Rogers, Wren, Foster). I suspect that a normal architect can only be an expert in one or two aspects of building, so the complete package has to be done by a team of specialists. Personally, I would place my trust in a good mechanical engineer, the building regs and some pictures of a house or features that I would like to incorporate. @PeterW I missed your reply, but I generally agree.

Why are we discussing architects? we have a habit of chasing them away on here

Proper Cornish then me hansom

Just logging around the house, so cables would be no more than 10m long, probably a lot less. I was doing it with DHT22/11s, but the 11s proved unreliable and inaccurate (I do have some more 22s which seem much better, must rig some up and calibrate them). It would be nice to use very cheap equipment if it proves accurate and reliable, I seem to have reliable code (and simple) for my logging now, just a matter of time to see how reliable it all is.

The more I read about the two systems, the less I like them. I had read about the cable limitation on I2C, seems a good reason to avoid it for household data collection. It may be easier and cheaper to use a Zero with an ethernet adapter, would still be under 17 quid for 4 sensors. I shall try something out soon, just got a very busy week this week as I have a show at Land's End starting Friday for a week (kitchen table is full). All bad timing.

Terry I may not have made myself clear. I want to connect 10 of these to the RPI, and have a reliable RTC as well. Ideally, they will be on the same bus as that leaves RPi pins free to do other 'stuff'. Maybe they are not what I need for this project, just that they are ridiculously cheap and I keep reading that up to 128 of them can be connected in parallel. There seems loads of examples about using just one of them via the I2C, very little about using them via SPI, and then there is confusion about which bus protocol to use (some say you can connect two, others say up to 128, some say only on SPI, others say on I2C, all very confusing). There does seem to be a way to read them using the CSB, set it high and it is locked out, set it low and you can read it, I think. But this uses up GPIOs on the board, which is what I am trying to avoid. I can see why 1-Wire is so sensible, a nice easy address (shame you can't put your own name on it i.e. living room instead of 28-0516b2b58bff).

Lovely, I shall fall asleep reading that.

I have bought a few of these nifty temperature, humidity and air pressure sensors: http://www.ebay.co.uk/itm/302009695856?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT How do I connect they to a Raspberry Pi Model A so that I can read from all of them. I have an real time clock (RTC) already connected to the Inter-Integrated Circuit ( I2C) pin, and as I want to use several of these to check temprature and humidy, I need to run then via the Serial Peripheral Interface (SPI). I am struggling to find much about it from the hardware side, so uncertain as to how to wire them up. They have 6 pins (once soldered on): VCC = power GND = ground SCL = clock SDA = data CSB = ? SDO = ? I think that CSB may be the 'polling' pin to read from that device and SDO may be the data pin. These seem easy to set up on I2C as it only uses SCL and SDA as far as I can work out, but, as mentioned earlier, really struggling to find anything about setting them up on SPI.

If you are designing/building a custom control system, is it worth making sure that basic off the shelf controllers can be easily fitted if needs be. So take a room thermostat. It is fairly easy and cheap to design one that can control a switch with great accuracy (even add in weather compensation) and log data (and even publish that to a website). If in years to come, someone else needs to change that controller, it would be good that they can go to B&Q, get the most basic mechanical thermostat and just wire it in. Some marking up of cables would be necessary i.e. power to controller, control lines, but all cabling should be marked up anyway. Maybe something worth thinking about.

http://www.telegraph.co.uk/news/2016/09/10/keith-vazs-wife-says-i-forgive-him/