Difference between cheap and high price thermostat

[threezero]

So currently I have the hydrofarm cheapo thermostat. I'm about to achieve a 90f hotspot with it set to about 105f. my question is is seems to take very long to get it from 95-105 (on the thermostat) when the temperature drops at night the thermostat reading with drop within an hr from 103 to 93-94 and 3-4 hr later it would still be at around 96. I would have to leave it over night than it would hit 103 or above. But by than its morning and the ambiant temperature has risen alot already.

I'm trying to figure out if this is due to my low ambient temperature or would the heat tape heat up faster if i have a better thermostat unit say a herpstat or something.

[REBELLMORPH]

what size of heat tape&cage ? are you using and where is the T. probe located?

[threezero]

i'm using the 4 sweater box from reptile basic with back heat. Heat tape for this model is

40-60 watts of 11" flexwatt heat tape. I have both the central heating system and a oil heater in the room running 24/7 and the

ambient temperature is around 71f in the room and 75f in the tub. I'm a little concern with my setup right now because the oil heater is known to fail if ran for too long. there is no way my ambiant room temperature can stay about 65f if i don't ran the oil heater and the central heating at full blast.

[kitedemon]

Tubs do not insulate at all. This is part of the problem you are holding 4º a PVC enclosure is likely to hold more. Between insulation and fluorescent lights I hold 10-15º over ambient air temps. I run dual UTH warm and cool (controlled by a herpstat). The next best option is a side turned glass tank it also insulates better I have a few they hold 8-12º.

The differences between T-stats are not likely to help although if you are seeing spike it will with that.
Hydrofarms
accuracy +/-4ºF
hysteresis is about 3ºF
prone to backlash and swing
No safety features

Herpstats
accuracy +/- 0.9ºF
hysteresis 0.0
No backlash or swing
Hi/lo temp shut down, alarms, mechanical relay, self diagnostics, probes failure shut down, plus others. They have the most advanced safety features available.

[adamfritzsche]

My first questions would be, what is your ambient temperature like? I know when I first started, I had a dedicated room in the basement, but my ambient temps where about 70°F. With heat tape, getting my hotspots was mediocre at best, even with closed racks. I soon realized that heat tape is not a miracle worker. Once I heated the entire room to an ambient near 80, then my heat tape started working more effectively.

If the room cannot be heated and ambients are low. My next step would be to try and insulate the rack, assuming you are using a rack.

[threezero]

I have a very cold room... the joy of living up north lol.

without the oil heater running and blocking off a section of my large room my room and running the central heating system on full blast temperature range from 65-72f depending on the amount of traffic (opening and closing doors frequently would lower the temperature to 65f. With the oil heater AND the central heating system on I can get 75-80f ambiant temp, again that depends on the amount of traffic in and out of the room.

I just lock myself inside my room for 2 hour and periodic turning the oil heater on. the tub temperature is now reading 90f hotside and 81f cold side (thermostat reading 104.7f right now) I am getting this reading with a accurate unit that could be inaccurate.

Rich from Reptile Basic suggest i use the belly heat model instead but i don't think it would make much difference now because I think my problem is with unable to keep a good ambiant temperature.

How do i insulate the rack? can I do that while still making the tubs slide in and out easily?

I'm mainly concern with the dependency on the oil heater to maintain a satisfy ambiant temperature. First of all I cannot completely limit the traffic in and out of my room (I have people coming in and out all the time, I can't count on them to close the doors every time or to monitor the temperature for me so they know to turn on the oil heater when it gets too cold) and the fact that I have burn out many oil heaters in the past winters by running the heater all the time. It would sucks for me to be out one day and have the oil heater failed without me knowing and the ambiant temperature to drop to 65F

and no having it in any other location of the house would not help, my room is the hottest room in the house right now, rest of the house is definately below 65f.

So I guess a better thermostat would not help? I guess I will put off that purchase for a bit.

I'm already predicting a huge heating bill this winter =\

[kitedemon]

I had though you had just a tub. Racks really need to be in correct ambient temps they simply cannot heat ambients effectively any other way with out heroic efforts. Flexwatt UTH are radiant heat sources and by definition radiant heats objects not air or water. They do not change ambient air temps much. (objects heated release some heat to the air).

I have a rack in a room that is quite cool as well (below 68ºF) I have managed to hold correct ambient air temps but it is not easy. I have hot side and low wattage cool side flexwatt (4 and 17 inch) This hold surface temps but not ambient air temps. I found that the top two and lower three slots needed different set points so I have a herpstat pro (replaced by the HS4 now) Running upper and lower hot and cool heat tape. I also routerd slots on the bottom of each shelf the slots are covered by the flexwatt and have holes drilled in from the top of the one below each level. This creates a channel for air to flow from the ceiling front to the back ceiling of each level it runs in contact with flexwatt all the way. This added 2 maybe 3º to ambient air temps. I insulated the top, sides, back, and bottom with 1/2 inch blue foam insulation. This added yet another 3-4º (5-7º total so far) I have also changed the air flow patterns of the rack so the tubs are vented about 1 inch from the top on three sides. The closed side is to the room this gives the air a chance to warm a touch more. I got one degree more this way (6-8 total over ambient room temps) I also tape in the winter thermal reflective material to the sides of the of each tub (not blocking vent holes) this was good for another 2-3º (total is 8-11º over the ambient room temp) My rack holds 90º warm and 80º cool with an ambient temp of 77-83º . I had to increase the room temp to around 69ºF but past that I have no issues anymore.

I run failsafes as well as the tub bottoms are covered by heaters the 17 flexwatt does not get as hot as regular (low wattage) so it is much safer. In an wide open test (no snakes in the rack) I ran the flexwatt maxed out for 4 hours and it only hit 87º.

[threezero]

Thank you! here i'm hoping that I can just buy a rack and be done with it. I find that maintaining ambiant temperature around 75f shouldn't be a problem however that goes out the door when my doors to my room is open for more than 2 mins. ambient temperature drop a few degree, same in the tub however it take quite a while for the rack to warm up again. it take about 15 mins for the ambient to go back up to 75f but close to an hr for the rack to heat up again to 90f hotside and around 80f cold side. Because I didn't build the rack myself I'm worry that insulating it would make the tub hard to slide in and out. Where does one find the blue foam insulating material and the reflective material? Do you have a picture of your setup I can take a look at?

[kitedemon]

No but if you are just using a single tub (I am confused by your posts do you just have a lone tub?) I would NEVER go with a rack they are a pain to hold ambients and a nightmare to clean. I would just invest in a PVCx enclosure I have three and they are completely problem free for me at 68-9º I have no extra effort to hold correct temps rather than a rack. I have just over a 1000$ in mine at this moment.

4inch and 17 inch flexwatt the lower tub is in the 'summer mode' with the end with holes out not in.
Hosted on Fotki

insulation; the rack is a closed PVCx rack as well.
Hosted on Fotki

i have no yet needed to add the silver band to the tubs yet.

[threezero]

i have a four tub rack system. its gonna be more economic and space saving for me to have a rack as i plan to have several bps.

Now I ran into a another problem this morning. Forgot to turn off the oil heater when I went to work this morning and when I came back the temperature in the tub is above 95f at hotspot and my room feels like a sauna. The temperature difference between night and day varies too much I guess.

Seeing how hot my room can get with the oil heater I think I can get by with the oil heater on a timer or a thermostat and limit the amount of movement in and out of the room at night. How much flucation in temperature can a bp take? I know the hotspot should never exceed 95f I'm gonna watch the oil heater to prevent this from happening again but say if the night time temperature dips 10f or so for an hr or two would that affect the snake that much?

But I'm definately gonna look into some insulation material maybe with the material i wont even need to turn on the oil heater that much if at all.

Now that i saw the how high the temperture can get in the day time I'm seriously considering the herpstat or similiar unit with a safety system. Question though the probe for the herpstat is still gonna be place beside the heat tape and not inside the tub how does it know to shut it off? in the day time like just now my thermostat is reading 104f while the tub is reading 96f however at night 104f on the thermostat would yield a perfect 90f. how would the herpstat safety feature distinguish between the the two?