THG Heat tape. Dimmer question

[seang89]

Building my first rack. I am planning on getting some THG heat tape to use as Underbelly heat.
I was wondering if anyone uses this with a dimmer?

The plan is to use a dimmer in there and try to get it so that it stays a consistent 90-92f on the hotside, It will however be hooked up to a proportional thermostat just in case(johnson 419).
I have 7 shelves that will be wired in parallel, 5 of them having 1foot and the other 2 having 2 feet of heat tape installed. I will be using 4" width heat tape.
Does anyone else do this type of method or something similar?
What specifications would i be looking for on a dimmer and which type?

Any suggestions appreciated.

[The Serpent Merchant]

You cannot use 2 different sizes or lengths of flexwatt on the same thermostat. Adding a dimmer isn't going to solve the issue at all. You need 2 separate thermostats.

[seang89]

You cannot use 2 different sizes or lengths of flexwatt on the same thermostat. Adding a dimmer isn't going to solve the issue at all. You need 2 separate thermostats.

Understood. I will separate the two different types of lengths into their own thermostats.

But I think you fail to see what I was really asking. THG heat tape is supposed to run at around 110-115f. I want to use a dimmer to lower the output so that it isn't getting as hot when its on.

Basically so that the thermostat will not have to shut off the heat tape unless something goes wrong, or for whatever reason it gets to hot.

[KMG]

A dimmer is not going to work very well. Usually you have to continue to adjust the dimmer to stay where you want it. If you are using a tstat the dimmer would be useless and would not allow the tstat to work like it should.

[seang89]

A dimmer is not going to work very well. Usually you have to continue to adjust the dimmer to stay where you want it. If you are using a tstat the dimmer would be useless and would not allow the tstat to work like it should.

Sorry, I'm trying to incorporate this method because I'm using a traditional thermostat (on/off) not a proportional like previous stated. Sorry for the confusion.

[The Serpent Merchant]

Understood. I will separate the two different types of lengths into their own thermostats.

But I think you fail to see what I was really asking. THG heat tape is supposed to run at around 110-115f. I want to use a dimmer to lower the output so that it isn't getting as hot when its on.

Basically so that the thermostat will not have to shut off the heat tape unless something goes wrong, or for whatever reason it gets to hot.

A dimmer cannot respond to temperature change. A thermostat can. Why are you trying to cut the thermostat out of the equation? Let it do its job. What happens when the temperature in the room drops? If you are using a dimmer the thermostat won't be able to run more to keep the cage at the correct temperature.

Sorry, I'm trying to incorporate this method because I'm using a traditional thermostat (on/off) not a proportional like previous stated. Sorry for the confusion

I still fail to see a point to what you are describing.

[seang89]

A dimmer cannot respond to temperature change. A thermostat can. Why are you trying to cut the thermostat out of the equation? Let it do its job. What happens when the temperature in the room drops? If you are using a dimmer the thermostat won't be able to run more to keep the cage at the correct temperature.



I still fail to see a point to what you are describing.

The Idea is to have the dimmer set so it only reaches a desired temperature without engaging the thermostat to turn it off.
The temperature of my house rarely fluctuates, I have good airflow and good heating/cooling system. My house stays 71-72 all year round.

With a dimmer attached, and lowered to 70-80% power, would that not bring down highest running temperature of the THG heat tape?

You understand that if I use a traditional thermostat (on/off only). It is going to be turning the heat tape on and off every half hour or so.
A few months of that and I'd probably burn out my thermostat from clicking on and off 48 times a day.

Why have a thermostat even you ask then? for safety. if it decides to ramp up for no reason or get to hot, it will shut power down.

I'm trying to be clear as possible. If anyone has experience with using Heat tape with a traditional thermostat, any input would be appreciated.

[SquamishSerpents]

Use a proportional thermostat and it won't be turning the heat tape on or off ever. It will simply keep it at one temp by applying the appropriate amount of power.

I believe the failure rate on dimmers is MUCH higher than proportional thermostats.

[SquamishSerpents]

If you don't have. Proportional thermostat you can buy them pretty cheap. Herpstat intros are only $135 in Canada so probably much cheaper in the US. I imagine you could find one used as well

[whispersinmyhead]

I recommend getting a Herpstat or the Vivarium Electronics as a second choice. I love my Herpstat. A dimmer could be used as a fail safe by adjusting it so it was running close to the right temp and turning it up just a bit so if you tstat failed your heat tape wouldn't be running at max.

Since you already have the on off style tstat I would use that as a fail safe. Just set it at a higher target temp say 5-8 degrees higher than you main. The herpstats that aren't basic also have even better safety features.

Even though it seems you house is a constant temp it is surprising how much fluctuation you cage/rack can have. We don't have a large margin of error to play with and the temps can swing easily in small enclosures. I used a dimmer for three weeks while waiting for my Herpstat and although the room stayed at 70-72 I was having 5-8 degrees temp swings in my enclosure (4x2x2). That would have been worse in a tub. maybe your house is way better than my old place was but I wouldn't recommend risking it. It is way better to know it is handled for you so you can enjoy your animals. I still check temps everyday but that is just so I know everything is ok. I am not wasting time adjusting.

I don't have a ton of experience but I will offer what I have. Others on here will have much more to offer.

Good luck on your new rack! I am also building my first. Stupid tubs are out of stock though do I am waiting till next week.