Remote temperature monitoring

[Discus]

Ray - Mikrotik and Ubiquity make numerous off-the-shelf goodies that are pretty sweet. I'm rather partial to the Mikrotik stuff (most of my work nework backbone and complex stuff is Mikrotik, with a few Ciscos here and there as managed switches).

Using grid antennae, you'll easily go a couple of hundred meters (kilometers in fact). Set up is pretty easy.

[MadOrchidist]

Z-wave is a wireless system common in "home automation" set ups. The reason it might help you is that the individual units create a "mesh" network, so even if one unit is distant, another unit or two between it and the hub can repeat the signal, expanding the range. Maybe an outdoor light controller and/or an outdoor temp sensor between the house and greenhouse would do it.

I know there are z-wave thermostats, as well as temp and humidity sensors too. I'm not sure it would all be ideal for you, but it might be worth looking into

The other big benefit is that they can be accessed easily online, with an iPhone app, etc. and also tied into all sorts of automations, notifications, and nifty things . . .

[Discus]

Is Z-wave the same as Zigbee? It's quite short range compared to the sort of distances most greenhouse owners are looking to use it for.

[MadOrchidist]

Originally Posted by Discus

Is Z-wave the same as Zigbee? It's quite short range compared to the sort of distances most greenhouse owners are looking to use it for.

I think zigbee is something else. This is from the zwave alliance website:

"The range of a Z-Wave signal is strongly influenced by the environment; for example the number of walls that the signal has to move through. Typical ranges achieved by Z-Wave customers are 30 meters (90 feet) indoor and over 100 meters (300 feet) outdoors in the open air."

Sounds to me like a line of sight from the greenhouse to the home's wall, with some other module to repeat/extend the signal into the house is at least possible. The main benefit is still that is is a mesh network, so limited range of one unit does not limit the total distance that can be covered . . .

[Discus]

This is a pretty good summary of the differences.
Info & Answers: What’s the Difference between Z-Wave and ZigBee, and Should You Care?, by Julie Jacobson - Electronic House

[Ray]

Good article.

My current alarm system (not a monitor) is a Thermalarm (bimetal thermometer in which the needle is one electrical contact, and adjustable limit pegs - too hot & too cold -are the others) connected to an RF sending unit, which is basically a garage-door opener key fob. It is AC operated, but has a battery backup.

I have a long-range receiver antenna (~400 meters) snaked out of the house on the wall outside of my office, and its circuit board is connected to a Sensaphone.

For monitoring, I am using a LaCrosse Technologies wireless temp & RH device that does have an alarm function, but unless I happen to be in the office, I'd never hear it.

I believe I am going to begin stocking a variety of the LaCrosse units for local and remote measuring, as they are realistically inexpensive, reliable, and will suit most folks' needs - as long as they don't have a stone wall to try to get a signal through!

[Discus]

Or even worse, the chicken-wire reinforced plaster that a lot of houses in SF are apparently built out of. Handy when your ancestors build faraday cages into your house...