As part of planning works to our listed farmhouse (solid granite walls) in Devon we've been talking to a local company who are involved with a lot of the current SPAB research into internal insulation.

In particular we were hoping they would help us with a "in situ Material Thermal Conductivity" test - apparently to estimate your existing u value by drilling core samples - rather than monitoring over cold periods - (quicker and can be done any time of year). And also more importantly help monitor and log Interstitial condensation or: "Interstitial Hygrothermal Gradient Monitoring" as they phrase it! To monitor the changes we make and help inform the debate.

Anyway to cut it short this costs far more than we anticipated ( think many thousands), I know a lot of people here do various monitoring so thought there must be a way for us to do this ourselves, does anyone know of any home/diy approaches? Albeit slightly less professionally than the experts super expensive kit and monitoring devices?

Posted By: SteamyTeaGo to www.homechip.com and look at these, they are what I use.
http://www.homechip.com/catalog/product_info.php?cPath=21_31&products_id=47" >http://www.homechip.com/catalog/product_info.php?cPath=21_31&products_id=47

The trouble with i-buttons is that you have to take them out to read them.

There are various threads around in this forum and the navitron one about DIY humidity monitoring.

The AECB has a special offer on some slightly more expensive kit, but perhaps not as expensive as that you've been shown. Look on their website for details.

Have looked at ibuttons and such on the net but cannot find anything that would suit my purpose – just not electronics-knowledgeable enough I guess. So, can anyone recommend a robust device which could be inserted through IWI to an original wall surface, sealed in position and left in situ to be “tapped” for data at various intervals (anything from several times in 24 hours to weekly or monthly). I am imagining 3 or 4 wired probes that, when required, could be plugged into an appropriate data logger (mains or battery) to record temperature, humidity and dew point. I envisage manual data entry to a spread sheet i.e. simple stuff please, I do not want to get into sorting software/connection issues!

Posted By: DarylPIf you have the space,

Thank you for that - and price looks good too BUT I need something I can seal behind IWI and leave in place, then read off as and when.

Posted By: DarylPfit & forget

The only one I could find is the iButton with the holder. It really is not difficult to set up.

I did think of a slightly off the wall idea. I bought a cheap radio/clock/weather station from Lidl for about 7 quid. It has a temperature and RH sensor in it, and air pressure. You could bury that in the wall, make a window and take manual readings.
Treat it as a wall clock and weather station.

Yes, saw them, maybe I should get an AD converter, or they may be the frequency ones that JSH made a reader/logger for.

http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=8133

Bella, I'd look at the Emoncms/OpenEnergyMonitor stuff. They sell encapsulated temp sensors and the data logging system is actually pretty simple. The trouble with manual entry is that you cannot get the same resolution. YMMV.

Posted By: borpinThe trouble with manual entry is that you cannot get the same resolution.

What causes you to say that?

Reading some numbers and typing them into a spreadsheet or copy-and-paste of the output of a command line program would seem very low-hassle approaches to me.

What your after s pretty easy for just temperature, most good electrical multi-meters have temperature probes.
The RH one is harder.

If you don't go down the built in data logger route, how often are you going to sample the data? This is quite important as too little datapoints or if they are clumped together (say most mornings and evenings), then the data has a systematic error built in from the beginning and is probably meaningless.

The real problem is that there is little inbetween the DIY kit and the professional kit. If there had been I would be using it.

Posted By: bellaOr is there a structural/technical/electronic problem taking the humidity signals down a wire rather than down short prongs? That I would have no idea about.

That would be an alternative: rather than burying a formal humidity sensor as such you could bang a couple of (appropriate material) nails into some part of the wall (or a bit of wood buried in the wall) and bring out wires from them to use an ordinary wood moisture meter. I think people do this with straw bale walls. Calibration would be tricky, though, if you want anything resembling reasonable accuracy.

Ed Davies, good thoughts there but I cannot work out how a nail could transmit humidity data though temperature seems feasible. Perhaps something I don't know about metal and moisture. A piece of wood (say dowling of correct diameter, well sealed in place) for humidity - now that sounds something really useful for my purposes and could look perfectly Ok too. "What are those wooden discs on your wall? Oh those are my humidity monitoring points." Will take a look at the site

Ed, Yes that is the principle behind their operation.

It always beats me why so called 'damp professionals' use a ProTim meter designed for timber sections, and expect it to work when the probes are stuck into masonry, damp or otherwise....?

Posted By: DarylPIt always beats me why so called 'damp professionals' use a ProTim meter designed for timber sections, and expect it to work when the probes are stuck into masonry, damp or otherwise....?

Probably because they think they know what they are talking about and most people believe them as they have the machine.