Temperature reading at distance

[7Wannabe5]

What would be a cheap, easy way to know the temperature inside a structure that was about a mile away from you?

[jacob]

https://www.weathershack.com/listing/we ... eters.html

Something like this?

[7Wannabe5]

Yes, that would exactly serve my purposes, but I do not want to spend $80 or be tied in with a service provider. Maybe I will settle for knowing what the temperature was at various points of time. What would be the easiest cheapest way to know how hot and cold it was while you were gone from a location when you return to a location?

My next question concerns the collection of water vapor via condensation. Let's be optimistic and imagine that in the world of the near future, I have constructed a functional recycled-tire wall and plastic dome greenhouse with a keyhole shaped pit at its center. I live in a region with a decent level of precipitation where the frost line is about 42 inches below ground and the annual temperature range is generally between 6 and 92 degrees farenheit with humidity levels between 58 and 81%. I would like to maintain the humidity level in my greenhouse within this range if possible. Generally, a greenhouse will be periodically vented to release excess humidity. I am wondering if the water vapor could not, instead, be collected in a still like one of these designs below but using a funnel to be placed periodically into the keyhole pit in the center floor (or maybe the funnel would unfold against the walls of the pit and then if you pulled a rope it would fold back together into a funnel, like a flower petal design)? Anyways, my question is, would it be helpful to dig below the frostline and/or run some sort of pipe out the end of the keyhole to the external environment? Also, can anybody think of a good way I could sometimes allow rain or snow to come in from the dome roof above the funnel in the pit? I would note here that I do hold a purely aesthetic desire for the structure to resemble an inside-out snow-globe. Like it might be snowing outside and on top of the mostly transparent structure, but inside there are green plants and it is relatively warm.

http://adventure.howstuffworks.com/surv ... water2.htm

http://www.treehugger.com/clean-technol ... iopia.html

[Gilberto de Piento]

Assuming you have wifi, here's something you could build but it would still be $50 and looks like a big project: http://www.instructables.com/id/TempBug ... ermometer/

[7Wannabe5]

@Gilberto de Piento

That device looks really cool, but I don't have WiFi at my vacant lot. I might eventually put a hotspot there, but I might just choose to use the cafe around the corner. Could/would the device somehow store the data until I transported it to a WiFi zone?

I have a lot of problems to solve with this project. Unfortunately, I can only dig/hack through compacted earth/rubble for about 2 hours before exhausting my upper body strength, and usually I see abandoned tires all over the place, but when I need them they disappear.

OTOH, I'm thinking maybe a very large transparent version of something like this for on top of my dome:

http://www.amazon.com/Petal-Drops-Rainw ... B0044664U6

[7Wannabe5]

Hooray! I finally got down to over 30 inches deep today and completed my due south ramp entrance. So, tomorrow, I just need to wander around up and down alleys and visiting gas stations to find some more tires. I was having some doubts about the wig-wam part of the structure, but I confirmed that it was, basically, the same design used by the Ottawa tribe that used to inhabit this region. My newest idea was that I will cut the sidewalls off of some tires and put insulation at the bottom and pipe venting out and then 3 layers of black window screen in the middle and plastic glazing on the front and then it will be a super cheap little solar air heater. I am going to make the water collection petals out of thick wire and clear plastic. I think petals are better than a funnel because when they close up they will be neutral. This is really a fun project. Even if it turns out to be a folly, I won't mind the spend (budget< $300 including new drill kit.)

[Gilberto de Piento]

It doesn't look like it can store data.

One possible outside the box solution might be to point a webcam or phone camera at a regular thermometer and have it take pics at some interval. Then you could look through the pics to see the temp at any given time.

What kind of structure are you building? Why do you need so much temp data?

[jacob]

Most cheap-ass electronic thermometers will remember Min and Max Temp. Even the one built into my bike speedometer does this.

You can make specialized custom solutions with Arduino. But out of the engineering triangle of "cheap, easy, and good", you picked cheap and easy

[7Wannabe5]

Good suggestion with the timed camera, but I would have to attach probes to a cluster of thermometers to make it work. I am building a mini-earth-ship-green-house-survival-structure. I will want to know the difference between the temperature outside and the temperature inside at the coldest time of day, and the difference in temperature at the bottom of the pit vs. the top of the dome, and the rear tire wall vs. the front plastic wall, and the temperature of the air blowing out of my solar heater. I guess I could just hook up a variety of temperature activated switches, or just observe that my poor goldfish mini-earth-ship-passenger is now frozen when I return the next morning. I will have to visit the structure at least twice a day myself in order to zip and unzip the space-blanket night roof cover, unless I figure out some complicated method by which to automate that process.

[Sclass]

After going thru a bunch of automation schemes in my head I started thinking about you as a person and what you do. Why not get one of the neighborhood kids you mentor to keep a notebook and record temperatures on a bunch of dime store greenhouse thermometers? It would be a good educational opportunity for the kid. You can get remote updates with a cheap dumb phone and do some mentoring at the same time. You get temperature data, kid gets $100 in $1 installments that would otherwise be dedicated to an electronic gizmo. Kid gets exposed to something real and scientific.

I use these at moms and view them across a room via webcam. A kids sharp eyes can read it from 30'.

http://www.webstaurantstore.com/taylor- ... aQodff0IsA

[7Wannabe5]

@Sclass:

I do plan on involving some of the neighborhood kids in my project, especially after I acquire some livestock next spring. They already come up and talk to me about what I am working on whenever I am there. However, I don't want to ask a 12 year old to go out in the middle of the night to read a thermometer. OTOH, your suggestion made me realize that I could very easily avoid one of my daily trips if I paid a child to open or close the space-blanket in the morning or early evening.

My abandoned tire hunt was successful, but I didn't have enough energy to haul all of them across town two at a time in my garden cart, so I have to finish that task today if it stops raining. One of my neighbors offered to sell me a giant roll of clear plastic at a very good price, but I suspect that he is somebody who perhaps goes a bit beyond the pale in his scavenging practice. He told me that there used to be a large brick storage building on my lot and that is why I am having to dig through so much rubble. I am a bit frustrated with the lack of good information available for calculating how much you can "safely" bend pvc, but I figure worst case scenario I might have to add some 45 degree angle joints to my design. It's fun going down in my pit and looking out across the ground at eye-level like a rabbit.

[Sclass]

@Sclass:

I do plan on involving some of the neighborhood kids in my project, especially after I acquire some livestock next spring. They already come up and talk to me about what I am working on whenever I am there. However, I don't want to ask a 12 year old to go out in the middle of the night to read a thermometer. t.

Good point. Fondly recall that wind driven ice in Windsor at a client install.

There are some really cheap usb temperature loggers on eBay out of China. I found them under "usb temperature logger". $14 gets you a device that you leave unattended and it collects data every 15s for up to a year on a coin cell battery. Best to try one first before buying a dozen...these chinese designs are often poorly engineered or made. Apparently they're used to ship with frozen foods to make sure your shipment stayed cold. You may be able to get a better deal on Alibaba if you need a dozen.

if you have AC and sprint 3G coverage, a Freedompop hotspot is free after the $20 setup and hotspot cost. Keep it under 500MB a month (easy if you're just taking temperature measurements every ten seconds) and you have cheap telemetry via wifi to a PC. With a cheap usb data acquisition dongle you can meaure temperature cheaply with an LM35 sensor from National Semiconductor. Wiring is pretty easy power, ground and signal. Three wires between each sensor and the USB dongle. Remote login and bang, temperature telemetry.

The beauty of doing it this way is you can put in a few door switches for a burglar alarm, or float switches for a flood alarm. Fire alarm etc.

I'll add some links later.

Freedompop LTE free hotspot
http://www.freedompop.com

A cheap data logger for your PC.
http://www.dataq.com/resources/pdfs/dat ... sition.pdf

The easiest and cheapest way to digitize temperature measurements. I forgot, TI bought National. I'm dating myself.
http://www.ti.com/lit/ds/symlink/lm35.pdf

[7Wannabe5]

Excellent!! Except, explain to me like I am very stupid why I need AC? A floodlight alarm would be great and my neighbors would appreciate it too, because there is egress from an alley to the vacant lot next to me.

[Sclass]

If you're going to run a PC or a wireless hotspot you'll need power. Were you thinking of solar?

The data logger from Dataq didn't have many channels for lotsa temperature probes or switches. You may need something with more inputs and outputs to handle things like alarm switches etc. and relays for sirens. I just tossed that up as an example. Maybe your time would be better spent on the structure first. What I'm suggesting will take some time investment.

The little USB thing I mentioned first won't require any power other than the coin batteries.

Eventually you'll probably want some power in the place. Solar and inverters would be great for light demands like an alarm or lighting. It's good to have some remote control and monitoring since you won't always be there. Flooding is always a big concern if you use automated irrigation.

[7Wannabe5]

@Sclass

Thanks for the info. I am thinking solar long term, but all I have right now is a big heavy rechargeable 12 volt DC supply lead acid battery with air compressor, jumper cables and light, and 3 small 20 volt rechargeable lithium battery packs I use to power my tools. I could power the hotspot directly with the 12 volt supply and haul it away to be re-charged periodically. However, it will likely be stolen if I don't chain it down. One thing at a time...

I finished my tire hauling task today. Unfortunately, although a two tire high stack was still pretty unobtrusive, three tires high is kind of ugly. A berm is not appropriate and would be a lot of work. So, I'm thinking of either adding some very inexpensive bamboo skirting or spray painting the north sides of the tires hot pink. Bright colors attract birds and bees, and nothing says "This is not a scary structure or a cool place for delinquents to hang-out" better than Barbie colors. I was down in my pit behind my tires this afternoon, and I think I frightened a child walking by on the sidewalk when I popped up. On a more positive note, it was pretty chilly with a brisk wind blowing today, and it was noticeably warmer in the pit behind the wall even without any kind of dome cover or surround in place. I was concerned about the fact that the wind usually comes from the west, but the not quite half circle of wall seems to be adequate.

[Riggerjack]

Just some structural grumbles...

I assume your 9 degree f lower temp range is a high in the winter? I thought Detroit got colder than that...

In any case if you want to bring heat and moisture up from below your 42 inch frost line, how do you plan to deal with condensation, frost, interior ice build up?

You can increase the temp exchange by driving grounding rods and then running a conduction loop around your space. This will keep it cooler in summer, warmer in winter, but not much. I considered this for a storage building, trying to keep it above freezing. I have a backhoe, so I'll probably just use a liquid loop and an old radiator, but if I didn't, I would use the ground rods.

Earth bag construction was designed for southern desert states. Places without snow load. How much snow will you get? How much water will ithold in spring? How upset will you be if several hundred pounds of slush come to meet you unexpectedly?

You will never find structural info on PVC pipe. It bends so much when warm,and gets brittle when cold, and breaks down under UV. It is good for moving water, not for structure.

I REALLY like alternative building techniques, but if they aren't suitable for the area, or use the wrong materials, you are building a labor intensive, delayed trash heap. I've done it myself, and have no issues with others doing the same, so long as they understand what kind of timeframe they can expect out of the thing.

Simple rules:

Protect plastic from temperature extremes and sunlight
Glass is a reasonable insulator, for its thickness
If something is electrically conductive, it is thermally conductive, and vice versa.
Fiberglass insulation doesn't work when wet, and if it isn't sealed, and condensation is possible on either side, it will be wet.
When vapor sealing fiberglass, seal on the warm side, ventto the cool side.
Foam insulation standsnup well to water, but not bugs or mice.
Snow load is no joke. Every year, buildings that have stood for decades collapse under unusual snow loads. In sheer stress, is earthquakes and windstorm, that snow weight on top adds to the sheer forces.

With that, good luck, and I hope you are happy with your new building.

[7Wannabe5]

@Riggerjack:

My structure is meant to not appear or be permanent. It's meant to be the urban scavenger's version of a wig-wam greenhouse based on the sort of modular design IKEA sells. That's why I dug a pit, but I won't build a berm or bury the tires. 9 degrees is the average daily low during the coldest time of the year. It does get much colder than that sometimes. I was thinking about digging down below the frost line, and may do so at some later time, but for now my pit is only 30 inches deep, and mostly meant to serve the purpose of allowing me to stand up and do tasks like potting even though the dome is less than 4 feet above ground level at center. However, I assume I will get some degree of extra warmth above ground simply due to the coldest air sinking into the pit. My plan for dealing with snow load is to borrow the curved design used by the Ottawa tribe who lived here in the winter. However, you do bring up a very good point and likely flaw in my design, because I was going to start the bend of the dome from up the side of the earth-filled tire stack, but that might create a junction that would be subject to pressure under snow load. Probably would be better if I didn't tie the tires into the frame at all. Also, maybe I should use saplings instead of pvc pipe. More bother to acquire, but cheaper and prettier and won't get brittle. Depending on diameter, the snap clamps I purchased to attach the plastic sheeting to the pipe might still work. There's a ton of grape-vine at the back of my lot, so I could use that somehow too. Thinking, thinking...

Anyways, the main point of my design is that the majority of the materials used are either retrieved from the trash or found on site for no cost, and the majority of the other materials used can be retrieved for re-use when/if the structure fails or I choose to disassemble, alter or expand it. I have spent less than $35 on actual materials so far. I also bought a new drill/driver (was on super-sale and came with extra battery that works with my weed-whacker for which I need more run-time in the summer) and an old roofing shovel, but I will obviously use these for other purposes such as bulb planting and the type of terrible carpentry work I sometimes produce (my style/method is just keep adding more braces until the damn thing seems sturdy and then cover it from view with a decorative ruffle.) This is mostly just a very fun experiment/activity for me. Some people climb mountains in their free time, I haul abandoned tires two at a time across an urban landscape in a garden cart.