can't regulate temprature in handmade incubator

[gemtruker]

a friend made this nice incubator he installed a new wafer thermostat. he's got two 250 watt bulbs. the problem is there is a 6 degree swing before the heat cuts on/ off. Ideas?

 

[Rod-T]

a friend made this nice incubator he installed a new wafer thermostat. he's got two 250 watt bulbs. the problem is there is a 6 degree swing before the heat cuts on/ off. Ideas?

So it gets to hot after thermostat shuts heat off? Try 2 100 watt bulbs.. your bulbs are too hot

 

[Rod-T]

I hope he didn't use a hot water heater thermostat

 

[azjustin]

a friend made this nice incubator he installed a new wafer thermostat. he's got two 250 watt bulbs. the problem is there is a 6 degree swing before the heat cuts on/ off. Ideas?

Well, there's quite a few variables in play.

- For an incubator that size make sure there is more than enough air flow.
- Where is the temp being measured in comparison to the thermostat?
- 500 watts, especially on light bulbs, is going to take a while to cool down if both bulbs are on at the same time. (those things get freakin hot!) Maybe add another t-stat and control the bulbs individually?

Personally, I'd ditch the light bulbs and put a fan behind a heating element controlled with a t-stat. They're typically 225 watt so x2 if it's going to be cold where the incubator is kept.

Good luck.

 

[MeepBeep]

I hope he didn't use a hot water heater thermostat

Why not? My go to incubator is the one I made one night on a whim using a water heater thermostat... I did it as a proof of concept to see if I could build something decent from stuff laying around the house and it works so well that it has become my mainstay... I keep meaning to build a newer model but since that one works so well it's never been a priority...

In the three seasons I have use it I have only adjusted the temp once, that was last year when I took it out of storage when it was running a degree or so off, this year I took it out of storage and plugged it in and it's dead on and is still running dead on...

I'm betting those that say water heater thermostats are no good, simply have poor designs and blame it on the water heater thermostat...

Sure it has some air temp swings but that is not bad as it's the average of those swings and internal egg temp that matters, not the air temp at any moment... My fake egg (a 2 oz baby bottle full of water) holds dead on 99.5° without waiver when the incubator is closed up and running...

To the OP, I fail to see the thermostat in that design, it should be mounted above the lights about 6" away, so the fan blows across the light and across the thermostat for best regulation... Also I agree 500W is way too much remove one bulb and put that thermostat above that one bulb and see what happens...

 

[Rod-T]

I think hot water thermostats vary too much.. I'd use itc-1000. There only 16.00 and set to celcuis they can be set .3 variance.

 

[Rod-T]

Itc 1000 are also calibratable and digital

 

[MeepBeep]

I think hot water thermostats vary too much.. I'd use itc-1000. There only 16.00 and set to celcuis they can be set .3 variance.

Since my fake egg holds a dead on 99.5° with only a ±0.3° waiver at most I would argue against that based on an actual proof of concept build sitting behind me...

As I said air temp swings caused by the swing (hysteresis) of the thermostat are not what you have to be concerned about, a few degrees up or down in air temp swing isn't anything to worry about, as long as the internal egg temp remains correct and steady...

 

[Rod-T]

Since my fake egg holds a dead on 99.5° with only a ±0.3° waiver at most I would argue against that based on an actual proof of concept build sitting behind me...

As I said air temp swings caused by the swing (hysteresis) of the thermostat are not what you have to be concerned about, a few degrees up or down in air temp swing isn't anything to worry about, as long as the internal egg temp remains correct and steady...

I see so it worked for you... if it ever goes out.. are you gonna but another hot water thermostat? Or a nice digital thermostat that calibratable? For just few dollars more? Be honest

 

[azjustin]

I have never encountered any thermostat with a 6 degree hysteresis, unless programmed to do so. There is a lot to be said for something that is in front of you and working as designed vs. "I read it on the internet so it must be true".

MeepBeep has a lot of good points and is at the root of the equation: the egg temperature.

We cheat mother nature by using t-stats, humidity pans, trays, etc.. None of this exists in nature and I promise you that a hen gets off her eggs to eat and drink. But, those eggs are going to be really close to 99.5 regardless of the outside temperature, and THAT is the goal.

To the point: dump the extra lamp and your temps will be better. The outside of those lamps are probably about 400 degrees and would take a significant amount of time to cool off in a 100 degree environment. Two of them would take double that.