My name is Andrew and I am in the process of opening my first chocolate shop in Houston. My business will be creating 3.5oz 6x3.5" chocolate bars with a Selmi One tempering machine, and I had a few questions:
Thanks Clay. This is very similar to my existing cooling cabinet, but I just use a window A/C unit to cool and a double fan to better circulate the air. It works pretty well, but as you mention in the document, the A/C cycles on and off, so the temperature changes several degrees.
I like the idea of using the plenum with registers to better control the direction of air flow.
The cooling cycles on and off which does cause fluctuations in temperature that may or may not be meaningful.
More to my liking is that the TrippLite unit filters and dehumidifies the air -- before blowing it on sensitive electronic equipment while evaporating any collected humidity into the exhaust air stream.
Yeah, it's a little more expensive than a home A/C unit but I think the overall benefits are worth the price difference. And, as I mentioned, this should reduce the load on whatever A/C system is being used for the rest of the production space.
I would be very interested in seeing pictures of this.
I saw this on the DIY tab & then searched for it. This is a Wonderful idea. Thank you for sharing Clay. I think I can picture this in my mind, but want to confirm.
Is the layout of the shelving is staggered like a water jacketed table so the air flow comes in at the top and flows to the right across the top row, then down to the second row moving to the left, down to the third row, and so forth.
I've drawn a picture of what I can see in my head. Is this close? The picture I drew has solid shelves and wire shelves. Solid shelves to direct the air flow and wire shelves to allow the bottom of the molds to cool.
A cheap source of NSF approved shelving may be sheet pans. Two half sheet pans end to end would allow for a pretty decent airflow-directing shelf. Plus it would be easy to get some matching wire cooling racks to use as ventilated shelving. A couple of vertical supports and the shelving should be in good shape.
Here is a link to a water jacketed cooling table showing the water flow on page 2.
Is the drawing similar to what you've designed Clay?
Based on the description Clay posted to google docs, my understanding is that the airflow is all one-directional. It goes from the air cooler to the plenum, over and under the molds, and then out the other side.
So, Clay's design does not go back and forth as shown in your picture. I can't think of a reason that shouldn't work too, though.
Ben is right in his reply - my design is not serpentine like you've drawn. The flow of air is across each shelf and then exits. There is a plenum that acts as a manifold for distributing the air across the shelves. By using existing NSF-rated shelving (metro-style), actual construction is about enclosing the shelving and making the plenum which serves as a manifold for distributing the air.
I don't see any particular reason why your design won't work but there may be more of a challenge ensuring that the air flow will be the same above and below the wire shelves on which the molds will rest. You want to remove heat evenly from the top and the bottom of the molds.
Off the top of my head I think your design will require more construction to make it work and to make it rigid. One thing to consider is that you are going to need to match the capacity of the outflow fan with the capacity of the cooling fan. They want to be the same CFM. If the output fan is not drawing as much air as the push fan you'll create a pressure build up in the cabinet that will negatively affect performance.
Does anyone have a photo of this to post?
re: Chocolate Cryystallizer
I am tight for space, so a cooling tunnel will be very difficult to install. Has anyone had experience with modifying an upright refrigerator or freezer (like a single glass door merchandising freezer)?
I am wondering if it is possible to use oversized cooling capacity to ensure faster recovery and efficient cooling. Some of the True units have interchangeable thermostats and one thermostat (#800325) cuts in at 62 degrees and cuts out at 55 degrees.
I simply cannot afford an Irinox, I don't have space for a tunnel, and I can probably source an upright unit from an equipment auction at relatively low cost.
Any thoughts or ideas would be greatly appreciated.
There is a potential issue with using a refrigerator at higher than design temperature.
The pressure going _into_ the compressor is set by the cold side temperature; the higher the temperature of the 'evaporator coil' the higher the pressure of the gas. For each gram of gas being compressed, the compressor does less work, because the pressure difference (input to output) is smaller. But because of the higher input pressure the compressor is pumping more grams of refrigerant gas.
This increased mass flow can overload the refrigeration compressor.
Now a refrigerator _must_ be able to tolerate this sort of operation at least some of the time, because you need to be able to turn the thing on and cool it down in the first place. But the compressor might not last in extended moderate temperature operation.
Note that the above information was provided by a commercial refrigeration technician who had specific problems with _walk in freezers_ which people had attempted to use as _refrigerators_, in response to my asking about using a reach-in freezer as a 60F chocolate cooler. As a practical matter, using a reach in refrigerator at 60F may not actually be a problem, and if the refrigerator is specifically supplied with high temperature thermostats, then it it is very likely designed to tolerate such use.