Protimeter Hygrotrac Remote Monitoring System

[Emma Furniss]

http://aecb.net/news/2012/08/protimeter-hygrotrac-remote-monitoring-system/

[Matthew Thompson]

This is something I would be very interested in for our barn conversion. The link doesn't seem to work at the moment, are there more details?

[Emma Furniss]

Hi there, I've double checked the link and it is correct so there must be a problem with the site.  Can you try the link later for more details.  Thanks Emma

[Matthew Thompson]

It's working now thanks Emma

[Dave Howorth]

It's an appealing-sounding idea but is it cost effective? Each remote sensor has a wireless interface and presumably a battery. What do they cost? And the presence of the batteries means they can't be built-in unless there's some way to access them. Compare that with something like a 1-wire system, which is a bit more effort to install but then can be left to its own devices and is cheap enough to embed extra, spare sensors.

How are the wood moisture meters that are shown intended to be used? They don't look like they'd be reliable in thelong term if left in place pressed aginst a beam and indeed don't seem to be designed for easy mounting. So are they intended to be carried around to test exposed timbers? In which case, I'd say the wireless interface brings only a marginal advantage over a normal moisture meter.

[Grant McAlpine]

It's an appealing-sounding idea but is it cost effective? Each remote sensor has a wireless interface and presumably a battery. What do they cost? And the presence of the batteries means they can't be built-in unless there's some way to access them. Compare that with something like a 1-wire system, which is a bit more effort to install but then can be left to its own devices and is cheap enough to embed extra, spare sensors.

How are the wood moisture meters that are shown intended to be used? They don't look like they'd be reliable in thelong term if left in place pressed aginst a beam and indeed don't seem to be designed for easy mounting. So are they intended to be carried around to test exposed timbers? In which case, I'd say the wireless interface brings only a marginal advantage over a normal moisture meter.

I've looked at the documentation and would agree with the above. Its does have pros and cons. The web based reporting functions are very good. However, even with the AECB discount the proposal is a bit expensive for me.

Does anyone know of a less expensive wired system?

[Emma Furniss]

The AECB is interested to obtain information and feedback on low cost and effective solutions for building monitoring.  We would be grateful for any comments on this post - thank you.

[Dave Howorth]

I think defining the requirements a bit closer would be useful.

Is this for temporary use in a building or permanent installation?

What is to be measured? Temperature, humidity, moisture, CO2, wind speed, insolation, electrical appliance consumption, water consumption, door openings etc.

What size of building? I doubt the same solution is likely to be appropriate for both a single dwelling and an airport terminal.

To what extent is low cost permitted to be achieved by DIY construction, installation and operation?

Are any standards required to be followed for the measurements?

[Andy Simmonds]

It would be great to get a low cost option sorted. Hygrotrac is an opportunity to get a top end system available to members at reduced costs. I am using one on an IWI project (not my house) and it has the following advantages for us:

I dont have to drive to the site. saves time = cost.
I can analyse data via xcel download or via the online interface (graph based) - very good this bit, and print out reports.
batteries are meant to last 10 years or so. we have built the wireless sensors in. One has failed due to I think liquid water getting in to the area of that sensor from an unpointed brick subcill that NEEDS SORTING!! (the sensor is directly below). We have 11 sensors in place, 2 ambient, 8 in the walls and 1 in a ceiling.

Cost - I organised sponsorship to cover the equipment and online costs leaving us to cover the time involved. Others are getting the client to pay for it.

on self build/owner occupier retrofits a cheaper solution would be useful.

OUr webmaster is looking into the potential of the low cost raspberry computer...but we all need to get stuck in to identify the best affordable solution - then AECB could see if we can get a deal for that as well.

the way we used the sensors is fully described in my IWI risk presentation uploaded in the aecb conference presentation section on this website. here http://www.aecb.net/PDFs/conference12/Andy_Simmonds_Wall%20insultation.pdf

[Dave Howorth]

OUr webmaster is looking into the potential of the low cost raspberry computer...but we all need to get stuck in to identify the best affordable solution - then AECB could see if we can get a deal for that as well.

There's been quite a lot of discussion of this topic on both the Navitron and the Green Building forums. It's well worth looking at the sources of kit and the systems people have built.

Thanks for the link to your presentation.

[Andy Simmonds]

we are going to move this thread as is duplicating the dicsussion - bear with us

[Emma Furniss]

Threads now merged

[Andy Simmonds]

This is some useful info from Omnisense following a request for a short but detailed description of sensor technology used.
Also attached are some notes/pics following my early crude attempts to assess the issues relating to the customised use of the sensors at our IWI project in Herefordshire. I have recently been discussing issues arising with Pete Warm. To get a further sense of these specific issues I next plan to lift the 'legless' sensor body off the wood surface by 5mm and remove the seal, to see how close the RH readings come to the legged sensor. Aim is to see how close the temp readings can be taken to the surface in question and what this does to the RH readings. I will also be exploring Omnisense's (more expensive) surface mounted sensors in more detail.

"For temperature and humidity we use Sensirion SHT11 (standard accuracy) and
SHT15 (high accuracy) sensors.  So far since you have been purchasing GE
BLD9050 you have been using the SHT15 parts.  We also sell through OmniSense
brand sensors with the SHT11 parts.  These sensors are mounted to a approx
2" x 1" x 0.062" FR4 circuit board with no thermal isolation.  Conversions
are done according to the formulas in their data sheet, see attached.

Dew Point and AH are calculated/derived from T/RH using standard formulas.

WME is done using a pin type resistance meter and converting resistance to
WME according to the conversion tables in the attached report from the USDA.
Note WME is temperature compensated, also according to recommendations in
the attached report.

Note that because of the extremely low power levels our sensors operate at
there is no "self heating".

For free air vs boundary layer not sure I can help there.  Seems to me that
this would be highly dependent on the air circulation at the boundary layer
and any attempts to characterize this would be futile.  If what you mean is
the RH/AH of a captive air sample that has equilibriated with a "material
under test" then, again, not our specialty.  There is a large published body
of research as well as published ASTM standards for concrete moisture
testing ie the calcium carbonate or the ASTM equilibrium RH tests which
would likely prove very useful for this topic.