Thermostat Question

[chairman]

I am looking into thermostat options for my sulcata's outdoor shed and was wondering if anyone had any feedback to offer on some options.

For background on my shed and current heating options, I have a stanfield mat with controller, a delonghi oil-style heater with internal thermostat, a heat lamp, and available CHE's from 60 to 100 watts that I could also install. Since only my nights are cool I am currently only running the oil heater during the night and the light during the day. However, I get the feeling that relying on the oil heater's thermostat may not be the best in terms of both reliability and energy efficiency, so I'm looking to wire something up to cut power to the oil heater (and heat pad when it gets colder) to keep from overheating the shed.

I currently use a ReptiTemp 500R for my hingebacks' indoor enclosure and I am not absolutely thrilled with it. Don't get me wrong, the thing works decent enough, but it seems to only keep temps accurate to about 5-10 degrees. This isn't a huge deal indoors since my hingebacks would be perfectly fine in my home's ambient temps, but I'm concerned about the size of the temperature range for an outdoor enclosure. Has anyone tried one of these controllers in an outdoor shed in an area that will get snow about 3-4 days a year (or more)?

I recently upgraded the thermostat in my home so I have my old one sitting around. For around $12 I could buy a step-down transformer, use it to power the thermostat, and for somewhere around $30 I could buy a relay that could be used to cut power to the outlet that my heaters are plugged in to. Think indoor AC system without an air handler. Anyone done this? I have the electrical background to wire the sucker up, but for $40+ there are other options and I am trying to get the most reliable temps for the greatest value here.

I have also seen some in-line thermostats for around $30. These things seem to be an attractive choice since I won't have to mess with a low voltage circuit, but they're essentially non-reptile specific versions of the 500R. Anyone found an in-line thermostat they love?

I have found some basic adjustable bimetal thermostats for around $5. I would probably have to mount the thing in a schedule 80 box to protect myself and others from the risk of electrical shock/etc, but this is certainly a thrifty choice... if they'd work as accurately as I'd like.

Finally, I could always go with a thermal fuse. I could install a thermal fuse in the shed's electrical box that would keep the power on as long as the temperature was, say, 77 degrees F at the box, and it would shut the power off when temps got above that. All for around $1. Anyone tried this? I honestly don't recall how accurate these things are either, so if anyone has some experience...

I'd appreciate any experience with heat control for sheds in areas that can get quite cold. Also, if you think that my existing heat pad controller and heater's internal thermostat will work well, I'd like to hear that too.

 

[Tom]

I've been using the "A-Life" model. I bought them from LLL Reptile last year, for about $25 each, and they are working great. I have 4 outside in tortoise and lizard houses and 2 inside my reptile room to control my big oil heaters. Each one has three outlets on it and they are rated up to 1000 watts. All of them work great and hold the temps very steady.

 

[jensgotfaith]

I've been using the "A-Life" model. I bought them from LLL Reptile last year, for about $25 each, and they are working great. I have 4 outside in tortoise and lizard houses and 2 inside my reptile room to control my big oil heaters. Each one has three outlets on it and they are rated up to 1000 watts. All of them work great and hold the temps very steady.

Tom- can those be used with the Stanfield heat mats? I am thinking I want to get Tex one of those mats and I read that Yvonne really didn't like the controller that came in the combo box. I considered the next controller, but I was just trying to find something a bit cheaper if I could. Any suggestions? Otherwise I'll just bite the bullet and spend about $185 for the heat pad and the controller.

 

[Tom]

I use them on my Kane heat mats and they work great. I've never used the Stansfield mats, but I think they are very similar. I just don't know if the Stansfeild ones get too hot without a controller. Kane mats are designed to hold 30 degrees over ambient.

 

[chairman]

Can the "A-life" model be set to a temperature, or do you have to set it to a color and hang out with your temp gun to see what it does?

I also have the "cheap" stanfield controller and am not entirely thrilled with it. It gets the mat to 103 F at the lowest setting. If my tortoise were full sized I think this would be fine, but at 6" I'd prefer to keep the belly heat a little lower. Of course, I could always blow a couple bucks and install a thermal fuse on my heat mat, though I'll have to double check whether I could properly reseal it afterwards.

I was planning to use my new thermostat to run both the oil heater and the heat mat, so it is nice to know that your A life runs a couple items.

 

[Tom]

Can the "A-life" model be set to a temperature, or do you have to set it to a color and hang out with your temp gun to see what it does?

I also have the "cheap" stanfield controller and am not entirely thrilled with it. It gets the mat to 103 F at the lowest setting. If my tortoise were full sized I think this would be fine, but at 6" I'd prefer to keep the belly heat a little lower. Of course, I could always blow a couple bucks and install a thermal fuse on my heat mat, though I'll have to double check whether I could properly reseal it afterwards.

I was planning to use my new thermostat to run both the oil heater and the heat mat, so it is nice to know that your A life runs a couple items.

It has a temperature dial, and its pretty close, but I fine tune with a variety of thermometers.

I've run four 18x28" Kane heat mats and a 100watt Pearlco on one "A-Life" and had no problems at all.

BTW, I set my thermostats by the outside temp. I run the probe to the outside and when the temp drops below 70, it kicks on. I've checked the surface temp of the mat and plastron and carapace temps of my torts many times and it has always been good.

 

[chairman]

Tom, this may be a silly question, but how do you keep your enclosures from getting too hot if the probe is outdoors? My shed has heated itself to over 100F with my current setup, and high temperatures (right now) seem to be as big of an issue for me as low temperatures.

 

[Tom]

Even when its over 100 here during the day, it drops into to 50's nearly every night. We might have some days in the 60's in mid-summer. And it usually drops pretty quickly. With temps that low and a shed that big the air temp is usually only a few degrees warmer than outside. My heat mats basically warm the tortoise, not the enclosure. This is why I'll usually break out the CHEs when winter temps start dipping into the 20's or 30's at night.

 

[chairman]

I ended up going with a pair of baseboard heater thermostats. They ended up being around $15 each. Their circuit is switched so I can cut power to the circuit when I don't need heat. Each thermostat controls its own outlet. I have the heat mat plugged in to one and my oil heater plugged into the other. I tried using just one and I couldn't find a good temp for both the mat and the oil heater to run at; when the air temp was good the mat was a roaster, and when the mat was good the air temp was possibly too chilly. Now I've got it set so that the heat mat can't get above the mid 90's no matter how hot the air gets.

If the setup turns out to be unsatisfactory I'll be sure to update to give everyone fair warning for the future...

 

[Balboa]

I may be misunderstanding the full application here, and I'm new to the tortoise husbandry bit, but I am an Electrician.

Using the baseboard t-stat to control the oil heater is a great idea. You'll still get some hysteresis (the temps will fluctuate, that's the case with any standard, home type t-stat. They provide a full on/full off function so the hysteresis is need to delay switching long enough to allow the temps to distribute throughout the house) Only micro chip controlled types that can employ some sort of electrical feedback loop will be able to provide truly constant, proportional heating wherein the amount of power employed is controlled.

I would however be really nervous about using any home type t-stat on a heat mat without some kind of modifications. Under normal circumstances the t-stat is sensing the air temps to decide whether to turn on or not, so in essence its going to wait until that blanket heats the room to its set point to turn off, which may never happen without help of course. As long as there's no way that blanket can cook the tort by staying on constant, I guess that's fine, I'd just want to make sure of that. (say for some reason the oil heater wasn't working, the temps got cold, and the other t-stat would just try and keep heating).

on many of the modern electronic t-stats a handy individual could void their warranty and detach the the thermistor and run it remotely to something like a heat blanket, but that really doesn't save much money over the inline t-stats designed to be used that way and sold for reptiles The reptile ones I've looked at also provide that proportional heating the home units lack.

hope I'm helping and not hindering

 

[Tom]

Balboa, this is great input. Definitely HELPING. Thanks. Now I hope you know that you've opened a bit of a can o' worms here though. I'm going to be bugging you for all of my future tortoise electrical questions now. Haha.
I use the Kane heat mats. Those are designed to hold 30 degrees above ambient. When my shed gets to about 70, the thermostat shuts them down. I've been using them this way for around 7 years with no problems. Before I got the thermostat, I was either using a timer or shutting them on and off manually. The torts can always move off of them too.

 

[bettinge]

I like these, expensive, but industrial quality, 1 or 2 outputs for different set ranges, programable to 1 degree diff or more if you like, and can easily and safely handle a 1500w heater! The outputs can be set for heating or cooling control, or one of each!

http://www.honeyrunapiaries.com/sto...ge-prewired-temperature-controller-p-110.html

Or a single stage unit:

http://www.honeyrunapiaries.com/store/ranco-etc111000000-digital-temperature-controller-p-86.html

I bought the unit without wires and wired it myself. However there is little savings doing it this way as proper gage wire and connectors is not cheap. I basically bought a proper gage extension cord and cut into 2 peices.

 

[Balboa]

HEHE glad to help, especially you Tom, what you're doing for Torts is AWESOME! If I had more free time I'd probably be willing to drive down and do wiring for you in trade for a couple of those "cold tolerant" Leopards, LOL Something tells me there still not really cold tolerant enough for me. I know folks do it, but *shrug*.

Explained that way, it makes sense. (shutting off at 70 ambient, and hence Chairmen's reference to the mat not being able to get over 90) I just remember all the horror stories about those little heat rocks we used when we were kids, scared me off using anything like that. I would hope modern devices are safer though, who knows. As long as the device is thermally limited to never go over 30 above ambient, it should be safe enough.

*Edited* I had a lesson myself in how confusing this can all get. My first response was typed before the morning coffee had kicked in, and I immediately realized after hitting the submit button that I'd typed a bunch of non-sense gobble de gook. I quickly went back to fix that, apologies to anyone that saw that. lol

---

I've looked at units like that myself for my larger fish tanks bettinge. Probably worth the expense. Fish Tank heaters are terribly unreliable, and in a large tank you need to run several and keep them synced up. a pain.

 

[chairman]

...hope I'm helping and not hindering
...
Explained that way, it makes sense. (shutting off at 70 ambient, and hence Chairmen's reference to the mat not being able to get over 90) I just remember all the horror stories about those little heat rocks we used when we were kids, scared me off using anything like that. I would hope modern devices are safer though, who knows. As long as the device is thermally limited to never go over 30 above ambient, it should be safe enough.

No hindrance detected here, just feedback. And feedback is good.

When it comes to the oil heater, I agree that there will be variability in the shed temperatures. I just need to keep the temp somewhere between 75 and 85, so a little bit of variance doesn't matter much. Basking lamps on timers are available if the tortoise wants it hotter.

Since I have the oil heater running, the heat mat essentially provides an additional "hot" spot in the shed, and the only hot spot I currently run at night (though it operates during the day too).

As Tom noted, the heat mat I am using will heat up to 20* over the ambient temp (I am using a rheostat provided by the manufacturer to keep it below 30* over ambient). So, as long as my shed temperature doesn't climb over 80, my tortoise shouldn't cook if the mat runs 24/7. That baseboard thermostat ought to be accurate enough to open the circuit to prevent cooking. I did consider running a nice proportional thermostat like the ranco posted here to regulate the surface temperature of the mat itself, but mounting a temperature probe on or in the mat seemed a bit more trouble than its worth.

I also have one of those old heat rocks still laying around. I'm not quite sure what to do with it; seems a waste to just throw it away, but at the same time I really can't think of any applications for it and would feel guilty pawning it off to someone on craigslist. I'll probably end up repurposing the cord and using the remaining rock as a decoration somewhere, eventually.

 

[Tom]

So funny. I used to use those "hot rocks" for years. One day the thing would be smoldering and stink up the whole house and we'd go buy another new one. We were so lucky that they never burned my little box turtle. I guess he had enough sense to get off the thing when it started malfunctioning.

As an added note to the above posts, I really like the idea of heat mats for torts housed outdoors because even in a heated shed, the ground can get really cold. Since they are in direct contact with it, it can really conduct the heat right out of your tortoise.

 

[chairman]

I primarily added the heat mat because of how much Maggie said that Bob liked his heat mat. Since my cool weather season will be similar to Bob's (though thankfully shorter), I figured my sulcata would want one too. I got my sulcata shortly after you started having success with humid "desert" torts and, as a result, decided that having a natural dirt floor would be the best way to go to keep the humidity up for my new sulcata... but would also be a very cold approach to take. The dirt made the mat that much more necessary in my mind.

 

[chairman]

Just received my first "real" test of the system last night. Had a frost last night and the ground temperatures at 6 AM were around 27 outside my shed. Inside the shed the coldest floor temp was 50 (near the door) and averaged in the mid 60's most other spots. The air temp at the thermostat was where I set it at. The temp in the hide on top of my heat mat was in the mid 80's. The "cool" hide was around 70. My basking spot hadn't come on yet, but I would assume it'd still register at around 100 like it is supposed to; I'll look into lowering the bulb if necessary. All together it looks like my sytem was able to keep the shed temperature 30 degrees warmer than outside and kept the immediate space around my tortoise's "hot hide" warm enough under a freeze condition. Since I can get much lower temps, I am hoping this is not the limit of my shed's abilities. I'm not thrilled with the floor temps, but I am considering my options... like repositioning the heater (it is in the middle of the shed near a wall now), adding a parabolic reflector above the heater to redirect heat downwards (need to find a free mini-satelite for that), etc. So far I think I'd give my set-up a C+...

 

[Tom]

Mike, in 24 years I have never stopped "tweaking " my set-ups. I'm always learning new things and getting new ideas. That learning/idea curve has increased exponentially since finding this forum. I'm currently underway building the "Mother" of all tortoise boxes. Pics will follow in another thread, but suffice to say, my herd is going to have a warm winter for a change.

Your temps sound great to me and especially if you have a heat mat available for him/her to lay on.

 

[Maggie Cummings]

When the carpenter redid Bob's shed from storage shed to tortoise shed, he put plywood covering the existing floor. The floor, even with snow outside, never gets below 60. I have the heater on top of Bob's sleeping box and a little teeny fan blowing the hot air around. I'd be freaking out if the floor was in the 50's. Bob's pig blanket is on 24/7 and the ambient temp in the shed is 85 to 90.
Now that the weather has turned, Bob is using his pig blanket much earlier then before. Used to go to bed at 7 now it's 5:30. It's cold and raining here now.
Now that he is in the shed longer I run a humidifier in the evening to create the needed humidity. With that fan blowing the moisture covers the shed. It's hot and humid.
I don't like the idea of a dirt floor. It's too cold and not going to create humidity anyway. I would add a floor if I were you. It seems to me you have the cold and damp thing going on and that ain't good...Just my opinion...

 

[chairman]

The vast majority of the floor area was over 60. The only area near 50 was the 6" or so near the front door. I installed some weather stripping on the door, but it isn't nearly as air tight as I would like. My outdoor humidity is ranging from 40 to 50%, and the shed is drier than that. The heater really sucks the moisture out of the air. So, for the moment I think I'm ok, but I do really want to raise the temps. Cool and damp is definitely something I want to avoid. I may be installing a wood floor in the near future anyway. Within a month or so I should be moving from my current house and its little .25 acre lot to a new one on 1.4 acres (if everything works out well). The new house is a bit more in the "country," so I am going to have to beef up security on the shed. Right now my shed walls sit directly on the dirt- when I move, the shed is getting set on a block foundation with hardware cloth installed below the entire floor. I could do the floor in wood instead of using the wire, it'll primarily depend if I can get the whole dirt floor thing to work. The circulating fan and the humidifier do sound like great additions for a climate control system.

I'm looking forward to seeing your box, Tom. I had already planned to try and install an "annex" to my shed in the form of a burrow/bunker like the one you built (difference would be that my entrance would be inside the shed), but if I like the box better...