Thermal insulation for a plate heat exchanger - is it necessary?
Thermal Insulation for Plate Heat Exchanger - Is It Even Necessary?
If we use a plate heat exchanger in a central heating system or for hot water (domestic hot water) - the heat exchanger, like any device, loses a certain amount of thermal energy, which, penetrating the external walls of the device, ends up outside and heats our boiler room. This is nothing but unnecessary heat loss, it works like a small radiator heating a place where we don't particularly want it to be heated (and we'll pay for that heating). The heat that the heat exchanger gives off outside does not go to the house, radiators, or underfloor heating. So if we want to have heating without such weak elements and minor heat losses, we should insulate the heat exchanger.
Heat losses in a plate heat exchanger
It is worth noting a simple relationship here.
✅ The amount of heat released by the heat exchanger outside is directly proportional to the external surface area of the heat exchanger. In this situation, the larger it is, the potentially greater the heat losses in the case of uninsulation.
Modern heating systems are those equipped with insulation
Currently, there is a tendency to create efficient, economical hydraulic systems, which largely boils down to excellent insulation of heating devices. There is actually a trend to insulate every element of the system that is not in a place where we want the air temperature to be raised. This includes every half meter of pipe in the boiler room or other room that we do not want to heat.
✅ Exceptions are made only in rooms where heat loss (i.e., actually heating the room) does not bother us, e.g., if we decide that we don't mind some of the heat from uninsulated pipes escaping into the garage. In that case, we simply don't treat it as a loss. Similarly, an uninsulated plate heat exchanger will work approximately like a radiator fin when it comes to heating the room it is in (let's assume we're talking about a heat exchanger the size needed to heat a 150-250m2 house). If this is accepted or desired in a particular room, thermal insulation is not needed. However, remember that in this case, less heat reaches us in the living room or other living space.
Insulating heat exchangers fits into this trend.
The cost of insulating a heat exchanger
Regarding the purchase of insulation - it usually costs around 25-40 € for a plate heat exchanger for a single-family house. In the case of large industrial devices, insulation can reach much higher prices, even up to 100-150 € for a set.
✅ It is best to think about insulation when purchasing a heat exchanger - then it can often be bought much cheaper, as part of a set. Adding thermal insulation later - usually costs 20-40% more than in a ready-made offer with the heat exchanger.
If we decide to purchase thermal insulation for an already owned heat exchanger - we must remember that heat exchangers from different manufacturers do not always have the same dimensions. Just because insulation from a certain manufacturer is intended for a 30-plate heat exchanger does not mean it will fit all 30-plate heat exchangers, especially models from other manufacturers. Similarly, if the insulation is intended for a 30kW heat exchanger, this does not mean that this measure is the same for every manufacturer.
✅ It is worth checking the exact dimensions of the heat exchanger and insulation before purchase - or ask the seller.
☑️ It is also worth choosing insulation made of materials that provide good insulation - which is not such an obvious choice. Some insulation materials on the market have good aesthetics, pleasing to the eye, but have poor parameters when it comes to insulation (sometimes they serve a more decorative than insulating function). In the case of heat exchangers, the best insulation material on the market is polypropylene.
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Adam Zborowski - specializing in heat exchangers, their selection, and HE accessories on a daily basis.