Quote Originally Posted by The MG Pony View Post
Ok thank you rob, you covered the questions exactly as I meant to elaborate on! so I can skip to the next point!

As rob said the evap is normally sized for the load, and the load is usually calculated based on how fast we want to freeze our substance, as the marble will act as a cold bank sizing becomes not as critical as it normally would be for an air system, more pipe the better to a point, the game is surface area and as much contact as possible!

If you use epoxy it must be a type with hi thermal conductivity, we all know most mortars conduct heat better then most silicons hence why I said for mortar over all ells. with that size I'd use half inch, I'd wing it here and figure you'd need between 6.5k btuh for holding and about 12k btuh to pull down for speed, but a 6.5Kbtuh compressor will do the job just as well all the way through just slower for geting down to final temp. for making ice cream we'd be wanting about -6C ? seems like a good workable number for hand mixing aut to be soft enough?

Now here is the very important part as we need to select a refrigerant, so how will this system be tested and started up, do you have a professional who will be doing the final testing and charging for you? and what sort of running environment will it be in?
Thanks for the replies; sorry for not responding sooner. I've been ill the last few days.

Before I continue; the reason for my title: "Mix and match physical components - can I do this?" is that I am trying to find the absolute cheapest solution to do a proof of concept for this venture. By mixing and matching parts I am hoping to find a solution that uses off the shelf / pre manufactured items that are already fabricated for me (condenser, evaporator etc., and other components in salvage yards, metal reclaim yards, junk yards - wherever I might find an old fridge or complete AC system in a car that might work, to see if I can piece it together very, very inexpensively.

If the concept pays off; and there is a reasonable cash flow, I can invest in something more lavish.

Okay.

I get what you're saying about conductivity. In the back of my mind I had a slight concern when I mentioned Silicone.

I'm still confused about the mortar? Are we talking about Plaster? Cement? Something else?

How is this applied?

I learn something new every day, and this forum has opened my eyes to some new things - thank you.

Your replies lead to more questions for me. You talked about selecting refrigerants.

The unit I have in mind could be used indoors or outdoors and the climate where I am thinking about doing this would be very hot and somewhat humid. So the capacity would have to be pretty strong; The capacity of the system would have to render the surface to freezing very quickly and keep it there efficiently. Hence my affinity for the A6 compressor as it has some brute force.

When it comes to testing I can get a pro to work with me.

So, we begin. I will let you, the experts make recommendations regarding which Refrigerant out of the more than 350 or so I saw listed the Wikipedia.

How do I, as you say, size an evap for the load? How can I determine what my load is and knowing that, how do I determine the equivalent evaporator. I'm guessing it has to do with the type of refrigerant / pressure / expansion valve and volume of refrigerant in the evaporator?

Thanks.