Let's analise, what is the proper connection of a plate heat exchanger, what is the correct flow direction, which channel is for hot side etc.
✅ Nordic Tec plate heat exchangers have arrows on the nameplate, which are intended to remind the installer that the method of connection must consider the counterflow principle. This means that fluids flowing through the exchanger in its two channels must flow in opposite directions. Failure to adhere to counterflow is one of the most common mistakes when connecting, resulting in a significant decrease in heat transfer efficiency, meaning - an installation with such a connection of the exchanger does not work properly.
However, sometimes we don't really like this method of connection. We would like to connect the device counter-currently - but preferably in the opposite way to the arrows on the label... No matter how we rotate the exchanger - we don't really like the connection according to the arrows, and we are not willing to undergo laborious modifications to the installation...
✅ The answer is simple - we can freely reverse the flow direction, as both channels of the exchanger have the same capacity in both directions (at least if we're talking about NORDIC TEC plate exchangers). The arrows are only a reminder and are not binding for the installer or user. However, it is important to remember that when changing the flow direction of one channel, we must always change the flow direction on the other channel of the exchanger to maintain the counterflow principle.
✅In case of Nordic Tec plate exchangers you can choose freely the channel for a hot side, up to your convenience, as both are the same. In case of exchangers by other brands - the situation can be different, however if one channel is destinated for a hot side - it should be definitely marked.
Not entirely, there are also other rules for connecting the heat exchanger. Remember that regardless of the situation - ✅ the plate exchanger should be mounted vertically.
❌ We don't advise to mount a heat exchanger in horizontal position. Mounting horizontally does not ensure proper venting of the device, and an airlocked exchanger often becomes clogged or completely blocked.
We recommend using mounting brackets dedicated to plate heat exchangers, which will ensure a vertical position and secure, vibration-free placement. If not using them (other solutions can be sought, of course), it should be remembered that the exchanger will not function properly in a sideways or horizontal position. Mounting brackets by Nordic Tec are universal and can be used with all the brands from the market.
The plate exchanger diagram for a connection is quite simple as long as we remember the above principles - counterflow and vertical position. This can be roughly seen in the diagram below. It shows the heat source side (red arrow) and the consumption side (blue arrow). The connection diagram for counterflow plate heat exchangers from Nordic Tec is simplified, but it effectively covers this issue.
✅ According to the diagram, fluids in the exchanger cannot flow in the same direction; they must flow in reverse. Only then will the counterflow exchanger achieve its efficiency."
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Eng. Adam Zborowski - specialist in plate HE and pool heat exchangers. Daily dealing with technical aspects of inquiries related to these devices, mainly focusing on their selection.
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