Hey everyone,
Following up on my intro post! As a newer Crestie owner, the hardest part for me was dialing in the temperature gradient for a tall arboreal setup. I got really tired of the “guessing game” with heat lamp wattages for different enclosure materials, so I decided to use my background in product/engineering to build something to help.
I spent the last few weekends coding a free thermodynamic enclosure calculator.
Here is the link: https://habitatchecker.com(Just to be clear: this is a 100% free passion project. No ads, no paywalls, not selling anything).
What the physics engine currently accounts for:
Material Heat Loss: The R-value differences between Glass, PVC, Wood, and screen tops.
Substrate Thermodynamics:** How substrate depth absorbs and holds heat.
Probe Placement: It calculates where you should actually put your thermostat probe to avoid false readings (based on your specific heat source).
My request for the veterans here: Pure physics is great, but real-world husbandry is more complex. I’d love for you guys to run your current, perfectly dialed-in setups through this tool and tell me if the recommended wattage matches what you actually use successfully.
Please try to break the calculator and let me know if my math is off! Brutally honest feedback is hugely appreciated so I can keep improving the algorithm. Thanks!
Cresties do not need additional heat other than the room temperature unless the room they are in happens to be unusually cold. My room usually stays at or a bit above 70 degrees and that’s just fine for a crestie……
They absolutely benefit from it though, personally i don’t keep mine below 73/74 year round, but they will use temps of upwards of 90f if the tank is big enough to sustain a safe gradient. In most typical setups it shouldn’t get above 86 in the basking spot though.
That being said, I feel like an issue with this tool is that it doesnt take bulb-type into account - you usually don’t need as high a wattage of halogen for example as youd need from a CHE. Also, the ambient temp can change throughout the room, and day. Based on the tool, id need a 100w for my BP, but in actuality im using a 150w, as 100w hasn’t been enough in the past. I like the idea behind it, but i unfortunately think there’s too many individual parameters to make one that works.
You are 100% right! If the room is sitting at 70F+, a Crestie is totally fine without extra heat. My house drops to around 65F in the winter, which is what started this whole headache for me haha. But yes, for room-temp species, extra heat is often overkill!
Honestly, huge thanks for actually taking the time to run your BP setup through it. Good catch on the bulb types. You’re totally right that Halogens (IR-A/B) vs CHEs/DHPs (IR-C) throw heat completely differently, and my current math doesn’t factor that in at all. I’m definitely adding a bulb-type toggle in the next update.
Quick question on that BP tank (where it gave you 100w but you actually run 150w): what are the exact dimensions, material, and your average room temp? I’d love to plug those numbers in and see exactly where my formula is missing the mark.
And yeah, I’m with you on the skepticism. There are way too many variables for a calculator to be 100% perfect, and it definitely doesn’t replace a real thermostat. My main goal is really just to give beginners a decent starting point so they don’t buy a 50W when they actually need a 150W lol. Really appreciate the honest critique!
Sure! It’s a 90x45x60 glass tank from Repti-Zoo, 23c average room temp (24c atm since it’s getting warmer). Tried plugging the info in again myself, and it suggests a 150w now, though it does seem to overshoot the wattage a bit since mine isn’t struggling which your guide suggests it would. Mine is currently running at 65% power. Another thing to note is since im using overhead heating (incandescent, Exo Terra daylight basking spot 150w to be specific) im measuring the air temp not the surface temp. Last time i checked, the surface temp on top of my dudes hide was in the mid 30s and the inside of the warm hide around 30.
Oh man, thanks for sharing the exact specs! If your stat is dimming a 150w bulb to 65%, you’re effectively running it at ~97.5w right now. The crazy part? My v1.0 calculator originally spit out exactly 100w for your setup lol. So the math is actually tracking almost perfectly with real-world use!
About that ‘struggling’ warning you got when you re-ran it—did you happen to leave the dropdown on ‘Ceramic Heat Emitter’? It’ll throw a red warning for glass tanks with CHEs because it assumes all the heat just escapes the screen top. If you switch it to the Halogen/Basking option, it shouldn’t yell at you. Seriously, this is super helpful. Thanks again for taking the time to test it out!
No problem! Yeah in the summer/spring when the temps are a bit warmer like now, a 100w would probably suffice, but most of the year it isn’t enough. Its wild how much a 1c raise in temp can do 
All three bulb-types give me a warning - When i plug in my usual specs it states i would need a 267w halogen, a 365 DHP, or a 512w CHE, but my 150w incandescent is doing just fine.
What I plugged in exactly was:
- terrestrial
2.1) 32c
2.2) 23c
2.3) screen
2.4) mulch
2.5) 10cm
2.6) occasional misting
3)overhead heating
3.1) halogen
3.2) safest range
3.3) 45cm
I have the dimming thermostat probe slightly off to the side, kind of in the middle/a little higher than the top of the hide. Ive checked the temp inside the hide in the past with a probe thermometer to be around 30c, and the temp on top of the hide with an IR thermometer to be around 35c iirc. It’s been a little while since i last changed anything about my setup besides clutter placement, and he’s eating no issues so I can’t imagine those temps have changed much if at all. My thermostat is set to 31c since i measure air-temp slightly off to the side, and not surface temp right underneath.
The 45cm is to the top of his hide since it is placed right underneath the lamp, I imagine resin probably holds heat better than mulch. Lamp is placed on top of the screen.
I hope this is helpful! Even though i doubt it would be possible to make a calculator that can take every little individual consideration into account it would be great to have something that can give you a very good idea as to where to start at least
Hey man, sorry for the late reply. Got totally buried under my day job stuff these last two days.
I wanted to say a massive thanks for dropping your exact specs. You actually helped me catch a math bug in the backend.
Basically, the calculator was over-penalizing the screen top for heat loss. It was trying to calculate the wattage needed to heat the entire ambient air of the tank into an oven to fight the drafts, instead of just focusing on heating the basking surface via direct IR for a terrestrial setup.
I just tweaked the logic to separate ambient air loss from radiant surface absorption. Ran your exact setup through the updated version, and it now estimates ~155W for a Halogen — which matches your 150W incandescent perfectly! (And yep, it accurately predicts that a CHE would be useless from 45cm away).
Really appreciate the real-world stress test. Your data was the exact calibration the tool needed. The update is live now. Cheers!