Technical-Economic Evaluation of the Effectiveness of Measures Applied to the Artificial Lighting System of a School

Round 1

Reviewer 1 Report

The article should be supplemented by the following:

1. Often old lighting installations do not realize the required illuminance levels. The article does not demonstrate (measure) whether the currently installed lighting in the rooms meets the requirements of the lighting standard.  
2. The article does not refer to the change of potential problems arising from the power supply with limited power of LED systems. There is often a significant reactive power component, which significantly affects the final cost of electricity.
   It is suggested to refer to the change in consumption of three types of power, active , reactive and apparent for the entire system. In addition, the reduction of power in LED lamps causes in the power grid the problem of distortion of the current drawn and the appearance of higher current harmonics. There was no mention of the risks associated with the introduction of LED solutions.
3. The positive and negative effects of long-term (e.g. 15 years) operation of the lighting installation (e.g. maintenance, damage) were not compared.

Author Response

1. Often old lighting installations do not realize the required illuminance levels. The article does not demonstrate (measure) whether the currently installed lighting in the rooms meets the requirements of the lighting standard.  

R1. Thank you. All the illuminance values are reported in Annex section. In particular, the required data are indicated in Table 7. 

2. The article does not refer to the change of potential problems arising from the power supply with limited power of LED systems. There is often a significant reactive power component, which significantly affects the final cost of electricity.
It is suggested to refer to the change in consumption of three types of power, active , reactive and apparent for the entire system. In addition, the reduction of power in LED lamps causes in the power grid the problem of distortion of the current drawn and the appearance of higher current harmonics. There was no mention of the risks associated with the introduction of LED solutions.

R2. Thanks for your comment. That’s true and certainly relevant mainly in the case of outdoor lighting systems.
However, the contribution of the light load to monthly consumption is not so high, therefore, an increase in the absorption of reactive power is not able to significantly change the average monthly power factor on which the penalties are calculated for the users of the electricity system. Therefore, it was therefore to not consider this aspect for the sake of simplicity. We have added a new comment in the manuscript.

3. The positive and negative effects of long-term (e.g. 15 years) operation of the lighting installation (e.g. maintenance, damage) were not compared.

R3. Being a recent technology, there is not much data and information about the long-term effect. We have added some comments in the conclusions regarding the advantages of the LED systems. Furthermore, it has been clarified that a Maintenance Factor of 0.8 has been considered in the simulations.

Reviewer 2 Report

Thank you for this interesting article.

Maybe you can add the unit of DA in Table 2, and the colour temperature of the LED retrofits (just to be complete :-)).

Author Response

Thank you for this interesting article.

1. Maybe you can add the unit of DA in Table 2, and the colour temperature of the LED retrofits (just to be complete :-)).

R1. Thank you for your comment and your suggestions! The unit of the DA and the CCT have been added.

Reviewer 3 Report

Please write the legend for following parameters: DAav, DAmin, DAcon,av

Please explain how you obtain the date from tab 2 and what are the difference between rooms, and bathrooms. How did you obtain the no. of calculation point?

According with tab. 6, in case of gym, no. of lamps in case of post-intervention was reduce. Why?

An interested paper. Congratulation to the authors!

Author Response

1. Please write the legend for following parameters: DAav, DAmin, DAcon,av

R1. For simplicity we prefared to avoid the colours in table 2. 

2. Please explain how you obtain the date from tab 2 and what are the difference between rooms, and bathrooms. How did you obtain the no. of calculation point?

R2. As explained in section 2.2. 2 “The calculation points set in SketchUp are used by the Daysim software to calculate the average DAav, DAmin, DAcon,av for each room.”. The grid has been set with a step of 0.50 m placed at 0.80 m from the floor in order to know the values on the workplane. We selected the rooms located on the ground floor, characterized by different orientations and different intended uses: room 5 (South), library 1 (West), gym (East), bathroom (North). We’ve added more comments in the manuscript.

3. According with tab. 6, in case of gym, no. of lamps in case of post-intervention was reduce. Why?

R3. Thank you for your comment. In the verification of the status quo (pre-intervention phase) it was noted an oversizing of the system in terms of both the number of lamps installed and in power. In addition, as can be seen from Table 8, the gym reaches optimum lighting levels for most of the day without turning on the lamps. It was decided, therefore, not to use a row consisting of 3 lamps.

Round 2

Reviewer 1 Report

The corrections applied jump in to complete the article with the reviewers' comments.
The article may be accepted for publication without further revisions.

Reviewer 3 Report