We don’t need Inverter for process cooling as only constant load is required – TRUE or FALSE?
Unfortunately, misbeliefs can become common, and in time, can sediment in peoples’ minds very easily. No sector is immune to this. But we believe that big brands like Daikin can do their part by putting their expertise and knowledge at the service of people. This is what has led us here, writing this first article of a series where we are going to be ANSWERING MISBELIEFS.
So, there are different myths in the commercial heating, cooling and ventilation sector (HVAC), and we would like to help people recognizing them and knowing what is true and what is not. There’s a lot of information, for instance, about Inverter or VFD (Variable Frequency Drive) technology. We all know the Inverter is an electronic power component that, by varying the frequency of the motor power supply, modulates the compressor rotational speed (RPM) and in such a way, controls the compressor capacity.
Read more here about the benefits of using inverter technology
This technology is recognized being responsible for helping chillers and heat pumps delivering great efficiency performances, especially when it comes to part load efficiency, but it also seems to have to face the belief that it is not needed in applications that only require constant load.
Read more here about why part load efficiency is important
So, for example, we don’t need inverter chillers for process cooling as only constant load is required, and the unit/s will not have to operate at partial load, ever.
Is that TRUE or FALSE?
Well, the answer is false.
Applications like data centers, food process applications or projects requiring the cooling of industrial machineries are usually characterized for requiring constant cooling/heating loads during the year. But that does not mean the chiller will operate in the same conditions throughout the whole year. In fact, in order to ensure that the load request in a data center or a food process application is always satisfied, the chiller is designed to provide the proper cooling capacity in the worst operating condition for the specific climate region (design conditions). But while the load request is constant during the year, the ambient temperature is not.
The unit selected will have to be able to provide the needed capacity at design condition, but for most of the year will operate at different (more favorable) outdoor ambient temperature conditions than those specified as design conditions. This will require the chiller to operate at part load during most different moments of the year and this is exactly why Inverter technology might still have a lot of sense in applications requiring constant cooling/heating loads during the year. Because during those times the chiller will operate at conditions different than design, it will also perform differently in terms of energy efficiency without the help of inverter technology.
Here is an example!
Let’s consider the case of a fresh milk storage application. Milk is produced all year round, and the application is one of those that require constant cooling, load just like mentioned above. Considering a 3,000 kW system with 3 chillers delivering 1000 kW of cooling capacity, each. Daikin Inverter technology ensures a far better performance than fixed speed technology, which also translates into substantial savings on operating costs.
Check the tab below for the numbers!
|Location||ENERGY SAVINGS||SAVINGS ON OPERATING COSTS||ROI|
|South Europe||262542 kWh/year||39460 EUR/year||8 months|
|Central Europe||251770 kWh/year||25177 EUR/year||12 months|
|North Europe||223752 kWh/year||13716 EUR/year||22 months|
Are you working on a project requiring Inverter technology for great energy efficiency? Then, get in touch with the form below!