Stand-alone cases using hydrocarbon refrigerants like propane or isobutane are on the rise in North American stores, particularly as supplements to remote cases.

Some small-format stores are even going with full-store line-ups of self-contained propane cases.

But the market for self-contained hydrocarbon cases is just beginning to take shape, as more efficient variable-speed compressors enter the marketplace, and higher charge limits are on the horizon.

To get an overview of the market, caught up with John Prall, applications engineer, for Brazilian compressor manufacturer Embraco. Tell us about Embraco’s variable-speed compressors?

John Prall: We do both fixed speed and variable speed. Typically with fixed speed we are able to get some improvements in efficiency with each generation; our EMC family is a pretty big jump over the compressors that it is able to replace. But variable speed brings you to another level of efficiency and capacity. It’s a more interesting discussion to have because of the higher levels of efficiency you can achieve at variable speed, mixed with a natural refrigerant. In variable speed, we have the FMX range of R600a compressors and our FMF family, which is for R290.

In the case studies we did with the FMX, it brings a lot of benefits outside of the fact that it’s a natural solution with a higher efficiency – like lower noise levels and tremendously improved temperature stability.

HC21.comHow common are variable-speed compressors in the marketplace?

JP: I think North America is going to be a little hesitant to move in that direction, mainly because our energy regulations are just not that tough compared to what you see in, say, Europe, where the cost of energy is high.

HC21.comWhat about the stricter 2017 U.S. Department of Energy standards?

JP: I think hydrocarbons allowed people to meet the DOE standards without variable speed, and we’ve made some significant improvements in efficiency with our fixed speed as well.

HC21.comSo there is more uptake of variable speed in Europe?

JP: These products are new. So I would say if we talk in a year we will have a very different conversation about the volumes of these products.

HC21.comIs variable speed more expensive?

JP: Unfortunately yes. There is still an added cost to go to variable speed – you’re adding an inverter and you’re talking about a fairly complex compressor. But we are able to use smaller shell versions now than we could in the past, so we are able to mitigate some of those cost increases. The magnitude of the increase is dropping quite significantly next to where it was two years ago.

HC21.comIs the higher cost holding people back?

JP: That would be the first barrier.

HC21.comWhat about the ROI you get with greater efficiency?

JP: But who gets the ROI?  The end user has to understand that value to drive the OEM to want to make that solution. It’s going to be an investment for the OEM to developa product around variable speed and then update their product lines.  So if the end user is able to realizethat efficiency benefit and is able to put a financial number to it, then they could work with their OEM of choice to develop a product around this type of solution.

I tend to believe food retailers would be one of the first to look into variable speed asthey have a history of variable speed on parallel racks. Plus supermarkets really have an eye on their energy bills. I don’t think that link is quite as solid in foodservice as it is with food retail because you have a distributor, not an OEM, selling equipment to a foodservice restaurant.

“I tend to believe food retailers would be one of the first to look into variable speed.”

John Prall, Embraco

HC21.comHow will the market be impacted by the IEC’s proposal to raise the charge limit of R290 for commercial cases to 500 g from 150 g?

JP: The 150-g charge limit can make it very difficult to have a hydrocarbon-based solution that is financially sustainable for the end user. It’s possible to make large cabinets with the 150-g charge, but the number of compressors required to meet the load is quite high and could add significant cost. But 500 g would eliminate this barrier.

HC21.comWill the higher charge limit bring down costs?

JP: Yes, for sure it would bring down the cost. Where you once needed 4 or 5 compressors for one large cabinet, you could get away with one or two. It makes the cabinet much easier to construct for the OEMs, leading to labor and material savings.

HC21.comAnd that will drive a lot more investment in R290?

JP: Yes, we’re already expecting that. We have bigger compressors if the charge limit goes up. Anyway, the IEC is just one piece of the puzzle. It’s just the first critical hurdle to raise the charge limit.

HC21.comAfter IEC’s approval of the charge increase, would it take another year for the U.S. to adopt it?

JP: There are many groups in the U.S. that would have to approve the charge-limit change, including the EPA, UL and ASHRAE, before we could realize these benefits.

HC21.comDo you think R290 self-contained cases will become an alternative to central systems for food retailers?

JP: I tend to agree that in certain markets it just makes more sense. I would not expect a hypermarket to go that direction as much as small convenience stores between 5,000 and 15,000 sq ft. And of course they work as side loads, even in hypermarkets, if you want to put some refrigerated product in the store but not connect it to your central  rack.

HC21.comWhat about doors on cases?

JP: From a sustainability standpoint no one can argue that doors are not the right answer. However you have the merchandisers, who at the end of theday drive their companies. I guess there is some loss of impulse buying when you add doors. But then there’s the energy bill. So is it the lower energy bill with doors or more impulse buys without them? It’s a financial decision. Tell us aboutyour complete refrigeration system called the Plug n’ Cool?

JP: Technically it’s a sealed, full-refrigeration unit with the evaporator, the condenser and the compressor. It’s a little more advanced than a condensing unit. A condensing unit would not havethe evaporator because it only has what we call the high side  – the condenser and compressor. By including the expansion device and evaporator, it’s got all four of the major components, so it’s a total refrigeration unit that you drop on the top of the case.  The main benefit is that it is factory-charged, which improves reliability, and if there is a problem in the field, it is very easy to service.

HC21.comIs it available in U.S. market?

JP: Yes, we have been showing it for a couple of years, but now we’re at a maturity level for that product, and we’re really starting to bring the solution into this country. Having case studies in South America has really helped. One case study from Brazil features a family-owned store that used to run on R22. By switching over to an R290 system with the Plug n’ Cool, he saved a lot of money. He’s really in love with the system. I think it paints a nice picture.

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