Hello I have a question about using this reflective insulation. So my question is how many layers would one want to use an I also hear something about leaving an air gap so the insulation can work.???
If you are using the bubble wrap reflective insulation then there is no need for an air gap as it is made of air gaps. I use 3 layers held together with velcro and I lose about 2 degrees F over an hour, stirring every 15 min. I also put 2 layers and the lid. I gave the remaining amount I had to my friend and he only got to layers out of it and he has similar results with 2
One layer of Reflectix needs a minimum 2 cm airgap in order to achieve it’s insulation “R”-rating, and in many applications up to two 3/4" air gaps (sorry to mix metric and 'Merican) or combination with insulation batting.
The internet is full of people decrying the misleading marketing and advertising of Reflectlix.
You can build little 1" standoffs by cutting 1" squares from foamboard and gluing them onto the kettle side of the Reflectix insulation wrap.
The other option is to use THREE wraps of Reflectix. Three wraps were tested by @fermware (Mash Tun Insulation Comparisons - Complete - fermware.com and found to be more effective than having a 2 cm gap. It’s not a big deal because one roll of Reflectix contains more than enough to wrap any reasonable size vessel three times.
@squeegeethree’s experience bears this out, too.
BTW, adding a cap or dome of Reflectix is the killer move (but can lead to condensation issues).
This pic shows 2 layers that I sewed together with an industrial sewing machine. The third and final layer had the other bit of velcro. My buddy that I gave the remainder to just uses bungee cord to hold his wrap together.
It works so well that I cannot imagine doing anything else.
I use a direct fired mash tun. I place a blanket on my MT. Lose about 1-2°. And it was 20° ambient. Think sometimes this is over thought.
Is your mash tun a pot though?
I use a 15 gallon stainless pot as a mash tun. After the mash in I wrap it with a comforter and blanket and bungee it making sure to not leave the bottom exposed. Lose a degree or two over an hour.
That is a very neat job. I used the bungee method myself. Now I just toss a blanket over my pot.
Your setup is cool and looks way more professional than my stuff!
With 4 of us living in a tiny apartment I wanted all my mash equipment to fit in my 8 gallon pot. Which I pretty much did.