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jeff5may · 09-14-17, 12:05 PM

OK, so I've been doing some homework on brazed plate heat exchangers. I've found the entire sizing process is dominated by two types:

A: Gurus who will give you 3 answers to the same question
B: Spec sheet readers who say only one specific model in the universe will work

Being somewhere in between these two types, I have come to these conclusions:

-Smaller surface area per plate units cost a lot less than larger ones
-Extra plates don't cost add much cost if you want them
-Similar units are not rated the same between manufacturers or market sectors (on the surface) AT ALL
-Cross-referencing and comparing similar units must be done using engineering data, charts, graphs, math, and combinations of these elements

Considering these factors and parsing through way too many articles and sheets, I've found that for my situation, there is a fairly large range of products that will fit my 2 ton unit. Total indoor-side efficiency and destination temperature are the two main factors that play against each other. At higher destination temperature, a larger heat exchanger is needed.

On the small and somewhat less efficient side, for condensing duty only, a 3x12x24 plate unit will do the job. This is SWEP B8 size. In this width, running the BPHE in evaporator or condenser duty, a longer profile is needed for good heat transfer. From the guru angle, less longer plates are better than stacking more shorter plates. So in the 3 inch width, an 18 inch long 20 plate unit (SWEP B15 profile) is needed.

On the larger and more efficient side, a 5x12x16 plate unit will do the job as a condenser. For better heat transfer at not much expense, a 20 plate is better. For dual duty, a 5x12x30 plate unit (GEA FP5x12-30) is good for lower temp water, while a 40 plate unit is better for higher temp water. The 30 plate GEA model crosses to a SWEP B10-50 unit or an Alfa Laval CB25-34 or CB26-34 unit. The 40 plate GEA model crosses to a SWEP b10-50 unit or an Alfa Laval CB25/26-44 model. From these few models, pretty much all of the knock-off units can be compared.

The price range of most of these BPHE units starts out around $150 shipped to my door. Some of the larger units are right below $200. Prices go up from there if you are looking for name brand stuff. Taking a chance on used or old stock units is closer to $120 and up.

Does this sound right? I figured these things would be more expensive...

09-14-17, 12:05 PM	#8
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	OK, so I've been doing some homework on brazed plate heat exchangers. I've found the entire sizing process is dominated by two types: A: Gurus who will give you 3 answers to the same question B: Spec sheet readers who say only one specific model in the universe will work Being somewhere in between these two types, I have come to these conclusions: -Smaller surface area per plate units cost a lot less than larger ones -Extra plates don't cost add much cost if you want them -Similar units are not rated the same between manufacturers or market sectors (on the surface) AT ALL -Cross-referencing and comparing similar units must be done using engineering data, charts, graphs, math, and combinations of these elements Considering these factors and parsing through way too many articles and sheets, I've found that for my situation, there is a fairly large range of products that will fit my 2 ton unit. Total indoor-side efficiency and destination temperature are the two main factors that play against each other. At higher destination temperature, a larger heat exchanger is needed. On the small and somewhat less efficient side, for condensing duty only, a 3x12x24 plate unit will do the job. This is SWEP B8 size. In this width, running the BPHE in evaporator or condenser duty, a longer profile is needed for good heat transfer. From the guru angle, less longer plates are better than stacking more shorter plates. So in the 3 inch width, an 18 inch long 20 plate unit (SWEP B15 profile) is needed. On the larger and more efficient side, a 5x12x16 plate unit will do the job as a condenser. For better heat transfer at not much expense, a 20 plate is better. For dual duty, a 5x12x30 plate unit (GEA FP5x12-30) is good for lower temp water, while a 40 plate unit is better for higher temp water. The 30 plate GEA model crosses to a SWEP B10-50 unit or an Alfa Laval CB25-34 or CB26-34 unit. The 40 plate GEA model crosses to a SWEP b10-50 unit or an Alfa Laval CB25/26-44 model. From these few models, pretty much all of the knock-off units can be compared. The price range of most of these BPHE units starts out around $150 shipped to my door. Some of the larger units are right below $200. Prices go up from there if you are looking for name brand stuff. Taking a chance on used or old stock units is closer to $120 and up. Does this sound right? I figured these things would be more expensive...