Monitoring your house (or solar heating system) temps

What fun is having a superinsulated, almost passivhaus, almost(?) net-zero energy house without monitoring temperatures and relative humidity I say! So here is a summary of what I’ve figured out on that topic here in 2011:

I have no doubt that the accuracy and the resolution of the Onset HOBO units are far better, but here is a price comparison between a home-monitoring solution using the “weatherdirect” LaCrosse TX-60U-IT vs Onset HOBO U12 data loggers vs the even more expensive wireless Onset solution of ZW Series “Wireless Data Nodes”. The latter is what I would want (if I went with Hobos) because I am not satisfied with stringing wires all over the house and I don’t just want to “log” temps, I also want to be able to monitor/view them in at least somewhat real-time fashion. So one either needs a way to string wires outside windows and up the side of the house, or run the sensors thru cat-5 wire (telephone/ethernet lines already in the house) or… something.

OK, so here is the rundown:

Both offer:
– some substantial data storage on device if wireless connection (router to device) or internet connection (router to internet) go down
– no computer needs to be on (BUT… hobo needs to be connected somewhat I think since the ZW-RCVR connects via USB to a computer instead of via ethernet direct to a router.)
– no ongoing subscriptions needed for monitoring of temps/RH

Lacrosse Advantage:
– low price
– wireless sensors
– automatic FTP storage of data
– uses normal AAA batteries
– total no-brainer. no software install. No computer needed.
– each sensor has internal temp and rh sensors plus a external connection (and 6 foot waterproof wire and sensor) for measuring another temp
TOTAL PRICE FOR MONITORING 3 indoor locations, 1 outdoor: Approximately $120 total (1 router, 3 sensors) all available from Amazon website


Hobo wireless advantage:
– resolution
– accuracy
– looks like you might get nice graphs with the “HOBOware Pro/HOBOnode Manager” software . though using the FTP option with lacrosse one could pull that off easily enough I think.

TOTAL PRICE FOR MONITORING 3 indoor locations, 1 outdoor:
$200 receiver — HOBO Data Receiver – ZW-RCVR
$239 x 4 — HOBO ZW-003 Temperature/Relative Humidity (RH) Data Node
(or maybe there is a way to do 3 but use one model that has plugs for external sensors and buy 2 $35 6 foot temp sensors. That might bring the total price down slightly??? Call Onset to get the exact number of course.)
~$1156 plus shipping


Summary: I went for the Lacrosse solution since it is ~10x cheaper and so far so good. It might be interesting to compare temp readings between a Lacrosse and Onset unit. I’d love to do a review of the Onset stuff but can’t afford it.

Contact me if you have a better idea! I’d love to hear it! “One-wire” sounded intriguing, but I need plug and play and most look like kits.


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