Remote control of off grid furnace

[upa]

Thought I would share a recent successful off grid comfort experiment.  Now that we are in the grips of our typical deep freeze in western Canada and as much as I enjoy visiting our remote cabin in the winter I dread the long warm up of a typical cold soaked structure. Since we don't heat the house between visits I have often wondered how I could remotely start the furnace a few hours before arrival . Recently I started to take notice of newly available IP/Wifi thermostats, such as Nest, Insteon and Honeywell and wondered how I could integrate them in my off grid home away from home.

My current cabin heating includes a wood stove and a 45k btu forced air/vented propane shop furnace hooked up to a pair of 100lb propane tanks via dual stage regulator. Electrical power is sourced from the 20kw battery bank and 3k worth of solar panels.
Since the only available internet I have is a barely apparent cell signal, I looked into wireless cell internet wifi hub. It took a little trial as most of these cell devices sit behind cell network firewalls and will only allow one way internet communication, getting a public IP from the cell provider ended up being the solution, allowing for port forwarding or otherwise  two way communication. I selected the Honeywell wifi thermostat and it easily recognized and communicated with my cell wifi router. Now I can use the Honeywell android app on my smartphone and send a command via internet to start the dormant propane furnace and set a comfortable temperature set point 150km away well before my arrival. The thermostat will confirm the temperature and appropriately turn off the furnace once the setpoint is reached. The only problem that I did not anticipate is that the wifi thermostat sends a small info packet every minute or so to call home and otherwise update the Honeywell interface cloud. This works out to about 6 megabytes every 24 hours. While you would probably never notice this internet overhead on a typical residential broadband connection, this could represent as much as 200meg/month on a relatively expensive cell network. I am currently playing with the idea of putting the router on a timer and turning it off during periods it would likely never be used.

I successfully tried a remote IP camera unfortunately the data overhead was way too high to be practical on a cell network plus the speed required for a good video feed was challenging on a cell network with poor signal reception.

Next project is to hook up a netgear universal wifi adaptor to my outback mate 3 and try and receive solar system/battery capacity updates via the web.

[itpdk9]

This is interesting... does you propane furnace have a pilot that stays on all the time? or how does it work?  I have a 30,000 btu blue flame ventless heater that I am in the process of hooking up, wonder if something like your set up will work.  I already have internet access at my camp. 

[upa]

Basically it is a 50K BTU Mr heater shop heater


It has electronic ignition, mechanically similar to a typical forced air 80% efficiency home gas furnace but in a much more compact form factor. The Honeywell wifi thermostat sees it like a typical home furnace, sends it a start requests when there is a call for heat, the furnace start circuit initiates the exhaust induction fan motor, then fires the electronic igniters, once all 3 burners remain on for a couple of minutes the blower fan turns on until the appropriate set temperature is reached.

Not sure how the blue flame ventless are thermostatically controlled so unfortunately I can't give a reasonable opinion if it will work.

On a side note, I have been experimenting a little further, it looks like it takes about 1 hour to achieve a 10 degree(Celsius) rise in my well insulated 1100 sq/ft 2 storey cabin(r24 wall r40 ceiling), basically I can get the cabin from below freezing to a comfortable 20 degrees Celsius (or 68F) in about 2 hours, that translates to 4.5 lbs of propane consumed and then I switch to wood stove once I arrive. Which is much more economical than what it would cost to constantly replace the 6000 BTU/hr the house typically loses even when I not there. I figure I would probably need 150-200 lbs propane/month to just keep the place reasonably warm if I had to heat it constantly.

[noelk]

Came across this old thread - I am looking to do something similar. Currently i have a woodstove but would like to install a furnace. Question on water supply - what type of system do you have? If the furnace is off during winter, I am guessing you would need to drain water lines before leaving the place each time? Or are you leaving the furnace on at a low temperature?

[upa]

 The house is heated on demand only. We blow out the water lines, on demand hot water heater in late fall and the house becomes a dry cabin during the winter, we bring water in 5 gallon containers. Kitchen sink does not have a p trap so its fine to use, toilet and shower p traps have antifreeze in them and don't get used during winter. Folks have to go to the outhouse to settle their business and be otherwise smelly .

[Dave Sparks]

There is also a controller that will control the heating / cooling and other items of a home with a landline connection or cellular.

http://www.protectedhome.com/deluxe-freezealarm-p-16-l-en.html