I noticed that the aluminum plate below the glass plate gets rather warm, just from radiant heat from the glass plate heater.
Is there a reason not to put an infra-red reflecting blanket on top of the aluminum plate (something like a space blanket, but rated for the temperatures it will encounter) to reflect the IR radiation back at the glass plate? This should keep the parts under the glass plate cooler, and might make a noticeable difference in the power used when printing.
It should work fine. The only area of concern I can think of would be if you would get a weird eddy from the temperature change that might cause airflow and more bed cooling. And that’s probably grasping at straws.
Insulating the bottom of the silicone heater has been on my list of things to do. Its a common common recommendation for folks who want to improve the efficiency of a 12V heater PCB/pad. Similar to your idea of reflecting infra-red back into the bed and protecting aluminum plate. My purpose was to help maintain heat in the edge of the bed where there may not be heating elements.
I’ve used an insulation called Reflectix in the past with good success. Its like mylar bubble-wrap… probably need 3M 468MP tape as an adhesive. Adding the insulation should heat up the bed quicker and hopefully maintain more heat on the edges of the bed. A detracting characteristic may be the cooldown of the bed may be prolonged.
On my previous printer, a sheet of the insulation for the top of the bed helped reduce the pre-heat time (100C) from 10min to 6min. Luckily we don’t have that problem with the 24V heat pad on the TAZ…
I think that stuff might be too thick. I don’t want to suck heat away with thermal conduction, so the insulation can’t touch both the bottom of the glass and the top of the metal plate. I want an Infrared reflector to reflect the IR radiation back to the source. There is also no information on the maximum operating temperature for that stuff.
Well… in the description it says “Reflects 94%+ radiant energy”. But according to the spec sheet (also listed in the Home Depot page), its only rated to 180F (80C)… or something like that. At .3" it could be stuck on the aluminum plate and maintain a small air-gap.
But whatever… a piece of mylar sounds like a great way to keep the aluminum plate cool.
I think this would work:
https://www.pegasusautoracing.com/productdetails.asp?RecId=11221&utm_source=google&utm_medium=cpc&utm_campaign=1838-001&gclid=COCcmdDs1s4CFQ1sfgodmsANFQ
Looks like it would work fine.