[Tastebridge] [Noisebridge-discuss] liquid based non expanding insulation - name?

Rrmutt rrmutt at gmail.com
Sat Jun 9 14:07:40 PDT 2012


Hi Frantisek,

You don't need two Peltier coolers: you can change the direction of heat flow by reversing the polarity. But note that poor efficiency makes them lousy heat pumps. If you haven't worked with Peltier coolers before, don't forget that they have TERRIBLE Carnot efficiencies, somewhere around 5%. 

This means to (re)move 5 watts of heat energy, you need to put in 95 watts of electrical energy, which turns into waste heat you also need to remove! So don't get expectations up that you can rapidly chill anything substantial, and be sure to budget a gnarly heatsink and a fan. 

So as neat as they are, Peltier arrays are more suited to specialized applications than for chilling anything large—especially if you are concerned about environmental impact, because they waste a lot of energy. 



On Jun 8, 2012, at 11:44 PM, Frantisek Apfelbeck <algoldor at yahoo.com> wrote:

> Hi to all,
> Here is just a link to the blog about the experimental incubator which I finally uploaded. It is primitive, my first "technical" blog so please patients, you know "poco a poco".
> 
> https://www.noisebridge.net/wiki/LOG_EI
> 
> I am now starting to work on the heating and cooling unit. I plan to use two peltier modules and I wonder if I could connect each to opposite sides of one heat sink and switch one on for cooling when needed and another one for heating when needed. They would never be switched on in the same time. The advantage would be that I would have just one heat sink in the internal cooling/heating system and because I aim for quite insulated environment (from the outside) it would be more easy to make, just one inlet for the ventilation duct to the box and one outlet. 
> 
> Anyway I would be posting to tastebrige mailing list about that so who is interested please join, I do not want to create too much noise here.
>  
> Sincere
> Frantisek Algoldor Apfelbeck
> 
> biotechnologist&kvasir and hacker
> 
> 
> http://www.frantisekapfelbeck.org
> 
> 
> "There is no way to peace, peace is the way." Ghandi
> 
> From: Frantisek Apfelbeck <algoldor at yahoo.com>
> To: Hackerspaces General Discussion List <discuss at lists.hackerspaces.org> 
> Cc: Noisebridge <noisebridge-discuss at lists.noisebridge.net> 
> Sent: Saturday, June 2, 2012 7:29 AM
> Subject: Re: [Noisebridge-discuss] liquid based non expanding insulation - name?
> 
> OK, done! I have combined the polystyrene boards for insulation (30 mm for sides, 20 mm for the top) and polyurethane foam to seal the gaps between the polystyrene sheets and also between the internal polyethylene layer. Now it is nicely drying with bracing inside to keep the shape fine. I will upload some pictures in 2-3 days, I'm just leaving for first Korean Maker Faire :-))
> 
> Thanks a lot for the help to everyone! When I see the box of the incubator in front of me I'm happy. It certainly looks like a prototype but you know, it happened and I made it by my hands with help of others, exactly how I like it :-))
> 
> Sincerely,
>  
> Frantisek Algoldor Apfelbeck
> 
> biotechnologist&kvasir and hacker
> 
> 
> http://www.frantisekapfelbeck.org
> 
> 
> "There is no way to peace, peace is the way." Ghandi
> 
> From: Asheem Linaval <xormic at gmail.com>
> To: Frantisek Apfelbeck <algoldor at yahoo.com> 
> Cc: Hackerspaces General Discussion List <discuss at lists.hackerspaces.org>; Noisebridge <noisebridge-discuss at lists.noisebridge.net> 
> Sent: Friday, June 1, 2012 1:11 PM
> Subject: Re: [Noisebridge-discuss] liquid based non expanding insulation - name?
> 
> Assumption: Your have two cube shapes, one larger than the other, both missing one face (for insertion and removal of objects), nested Matryoshka doll style, and you want to insulate the airgap between the five remaining faces. In that case, have you tried bracing the PE cube from the inside with a removable plug? That might solve your deformation problem, and enable you to use the expanding foam.
> 
> Also consider a more typical insulation method, like covering the box in rockwool or fiberglass insulation common in hardware stores.
> .atl
>  
> On Thu, May 31, 2012 at 8:00 AM, Frantisek Apfelbeck <algoldor at yahoo.com> wrote:
> Hi to all,
> I need to insulate around 5-10 cm space all around an inner polyethylen (PE) box (5 mm thick, cube, a=500 mm) and between it's outer MDF board based shell (12 mm thick, cube, a=600 mm). The device is going to be an experimental incubator, so temperature insulation is crucial. I have tried to use polyurethane foam but it is expanding therefore it would distort the soft PE internal layer. I used partly a polystyrene board for the back but the boards do not fit exactly (thickness) and due to the fact that I used screws and brackets in the project a lot it would be hard to put the boards in anyway.
> 
> The best thing in this moment would be to fill the spaces between the boxes with some liquid un-expanding insulation which would get in all the spots, become firm and I would be fine. The plan is that I would insert the inner PE box, fasten it, flip the whole box on it's back side and fill the gap between PE box and MDF box up with the insulation and "happy ever after". Alternatively would you know if it would be feasible to brake down the polystyren boards on a small pieces and mix them with some glue and apply it in a similar manner? My budget for the insulation is $20-40 and I'm now in Seoul South Korea.
> 
> Thanks a lot for any help! It is a prototype so a great learning experience but I have spend more than 20 hours on building two smaller size simple boxes - bit slow I would say.
> 
> Sincerely,
> 
> Frantisek Algoldor Apfelbeck
> 
> biotechnologist&kvasir and hacker
> 
> 
> http://www.frantisekapfelbeck.org
> 
> 
> "There is no way to peace, peace is the way." Ghandi
> 
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> 
> 
> 
> 
> 
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