Trying to design a super efficiant heater

[cbiblis]

I am aware of how to use vent holes. The idea is to make my design more efficient then the others. The design that your showing is like all of the others out there. There has to be something that i can do to add to the other designs.

 

[crutschow]

You are looking for some magical solution to improve the efficiency of your heater and there isn't any. As everyone has stated there is nothing you can do to improve the efficiency of a resistive heater. Start-up spikes in a resistive heater are negligible and consume no significant power. The best thing you can do is build the box with as much insulation as possible.

If you were to really get fancy you could use a heat exchanger on the ventilation air going and and out of the box. It extracts the heat from the air going out of the box and adds it to the air coming in. That way you would lose only a small amount of heat through ventilation (depending upon the heat exchanger efficiency). Don't know if anyone builds one small enough for you application. If interested Google "air to air heat exchanger design" for some ideas. A simple design is two long coaxial tubes. The warm air going out one tube will transfer heat to the cool air coming in the other tube. The efficiency is proportional to the length of the tubes.

 

[tcmtech]

Time invested into research and construction. One week.

Insulation and building materials. $300

Value of electricity saved. $2

Lessons learned. Priceless!

 

[cbiblis]

That was another idea that i had. I thought that i could weave a 1/8" copper pipe through the heater coil with a fish pump to supply the air to the cabnet controlled by a o2 sensor. Or how about a 1/2" copper pipe ran from the outside through the center of the heater coil to heat the incoming air closer to temp then a standard vent. I don't know, i'm just brain storming here.

 

[cbiblis]

Just trying to re invent the wheel. LOL
Just trying to kill time until i get a job.

 

[HeatherM]

Use a heat pump. They are greater than 100% efficiency. For low amounts of heat you could use something like peltier junction devices. 2-4 of those could easily generate 225 watts of heat with a temperature delta greater than 100 degrees F.

From experience I know that one of the peltiers I was using used 80 watts of power input to heat some water with an equivalence of 200 Watt resistive heat.

The only issue would be icing of the device, but if you had an timed cycle of less than an hr, it should have time to de-ice if your using it in cold temperatures.

 

[cbiblis]

With my understanding of Peltiers, don't they heat on one side and cool on the other side? If they do They would contradict themselves in a sealed en-closer. right? How are you suggesting that i use the peltier?

 

[cbiblis]

The peltier idea is interesting. If i were to install a heat sink to the peltier and mount it in front of a fan would this work for heating a 8 cubic foot en-closer? Let us say a 158 watt peltier : 158W Thermoelectric Cooler Peltier Plate | Virtual Village - US

 

[Boncuk]

I am aware of how to use vent holes. The idea is to make my design more efficient then the others. The design that your showing is like all of the others out there. There has to be something that i can do to add to the other designs.

Why not connect an oxygen bottle to the incubator? If you just want a different (looking) design you should also think about a different design for windows, which are normally opened for fresh air.

 

[cbiblis]

I'm not trying to be a smart #ss, I'm just saying that vent holes are flawed in that they allow more cool air in then is necessary. This is why i suggested the air pump and o2 sensor. In turn the pump would only allow cool air in to refresh the oxygen until the level is reached then it would seal the encloser to trap the heat in.

 

[mneary]

Run the incoming air past the outgoing air so the heat is exchanged. I'm thinking of coaxial pipes.

 

[cbiblis]

interesting. So maybe a 1/8" copper tube with forced air running through a 1/4" tube 1/2" short for out going air. I wonder how long it would have to be to transfer the heat? Actually instead of forced air maybe convection would work in this application.

 

[cbiblis]

thanks Mneary for being a forum supporter. I've been looking for a way to give back to the support that i have been given but didn't know how. With your "Forum supporter" link i found out how.

 

[cbiblis]

Hey, how about using 1/4 watt resistors strapped to a 1/4" copper tube, like a telescope heater, using about 2 watts to heat the tube for the incoming air and allow the air to escape thru a exhaust vent at the bottom of the incubator?

 

[Boncuk]

I am aware of how to use vent holes. The idea is to make my design more efficient then the others. The design that your showing is like all of the others out there. There has to be something that i can do to add to the other designs.

You obviously didn't look well enough at my design.

As the cool air enters the incubator it will be mixed with inside air and addionally heated when passing the heater located on the downstream side of the fan.

Also, you can't close the incubator for some time (just to save 2W of energy). Fresh air must be added at all times. Using a sliding door to allow only the minimum fresh air to enter will keep heating expenses to a minimum as well.

No chicken will hatch from a rotten egg. Since air exchange is a constant factor regardless of temperature (the box size won't vary) you can easily find out the optimum setting of the sliding door.

Connect a plastic pipe/hose to the vent air port and inhale the air. If you get dizzy you know the air is of no good quality and probably push the slider open for one more hole until you can breathe the air out of the incubator freely.

Chicken generally breathe the same air as humans. So don't worry.

If you can afford purchasing a CO2-sensor and the appropriate controller, why not make it scientifically sophisticated?

I bet the chicken hatched will say "beep - beep"; neither will they say "quack quack" nor "Thank you for the fresh air".

On the other hand, why would one waste energy using an extra air pump having that energy saved for a super-efficient heating system?

Boncuk

 

[tcmtech]

I never realized a chicken hatching eggs was such a complex machine.

A friend has them and I've seen them sit on nests for a while then leave with the eggs unattended and out in the open for some time then come back. And repeat this until the eggs hatch most often without problems either.

I am pretty sure that the eggs are not that sensitive to temperature swings. If they where birds would have never evolved. I saw a guy that made an incubator out of a cardboard box some old mattress foam and a light bulb. He hatched out dozens of birds with it too!

This sounds more like OCD engineering than incubator design. If your out of work you should be concentrating on finding work not hatching plans about how to hatch chickens!
If you cant afford the electricity to run it you cant afford the parts to build the incubator either.

You put the peltier devices on heat sinks with one side inside and one side outside the box. Although as soon as they turn off they will instantly start transferring heat in reverse which will cause the incubator to cool off faster.

 

[Mr RB]

It's not that critical. Even small gaps around the door will let some of the warm air rise out, giving you a surprising amount of air circulation. It's one of the problems with incubators, stopping the warm air leaking out. And leaving the door open a crack (say 1/4") will double or triple the time the heater is on, giving you an idea of how much heat is lost as all that hot air escapes out.

 

[cbiblis]

Well you could stick eggs in a bra and where it for 21 days and hatch eggs.

The point of getting the specs right is to get as close to 100% hatch rate out of the incubator. People pay high dollars to get rare breed eggs.



Thanks for the fatherly advise


It's not about the building cost of the project, it is the sale perks.

 

[crutschow]

With my understanding of Peltiers, don't they heat on one side and cool on the other side? If they do They would contradict themselves in a sealed en-closer. right? How are you suggesting that i use the peltier?

You put the Peltier in the wall such that the cold side is on the outside of the box and the warm side is on the inside. A large heatsink (and a small fan if necessary) should keep the cold side from icing up. That will give you a heater that is more than 100% efficient as compared to a resistor.

 

[HeatherM]

Yes sorry I should have been more specific. The peltier would need to be mounted through the enclosure like a window. Heat sinks on both sides. Fans on both sides would also be required if the heatsinks are small. No air would pass through the enclosure but heat would be transfered from the outside (cold peltier side) to the inside of the enclosure (hot side) at a efficiency much greater than resistive heating. If you built a control circuit for this, you could potentially run the peltiers full time and they could settle into a state where they are heating just enough to keep temps balanced all the time with amount of heat radiating from the enclosure.

If using fans, it would be beast to shroud one side of the heatsink/fan combos so that when the device is off, it doesn't dissipate too much heat out of the enclosure while its off.

Some ice chest style coolers for camping trips have peltiers in them that run off your car battery to keep them cold inside.