17 Aug Building Efficiency through Energy Modelling
From our previous blog on energy auditing, we mentioned that there are three (3) levels of ASHRAE energy auditing, each level being more extensive than the last. For two of the BEA cities that we’ve worked with, we have conducted an ASHRAE Level III audit wherein we have added a building simulation model for a more detailed analysis of the buildings. Due to the COVID situation however, we were not able to collect more data physically which could help in developing the model more accurately.
Energy modelling can serve as a tool to estimate building power consumption even for new buildings that haven’t been constructed yet. This can help developers and other stakeholders check their designs to see if these would fit the existing national policies such as the National Green Building Code and the Energy Efficiency & Conservation Act. Aside from this, local government units can develop corresponding local green building ordinance policies with the help of various energy modelling tools.
The eQuest software was used to estimate baseline building energy consumption for the cities of Mandaluyong and Santa Rosa, from which various energy conservation measures (ECMs) were recommended according to their economic viability.
A building energy model would require an array of parameters in order to obtain its overall power consumption. The main factors would usually be 1) Building envelope, 2) Heating, ventilation, and air-conditioning (HVAC), 3) Operation schedule, and 4) Other building loads such as lights and office equipment. Data gathered from the previous walkthrough energy audit as well as building pre-audit information such as floor plans and electricity bills were used to estimate these parameters.
The baseline building consumption was then used as basis for ECM comparison. Various energy conservation measures were tested against the model, from using better performing glass for windows to replacing air-conditioning units with more efficient ones. Aside from this, packaged energy solutions were also done wherein two or more ECMs were modelled at the same time to show the effect of shared energy savings. It is important to know that the law of diminishing returns applies here, wherein the shared effect would not equate to the summed effect of the individual ECMs.
To analyze whether the ECM would be financially viable to the stakeholder, a quick economic analysis was done which looked into the simple payback periods (SPP) of all measures. A lower SPP would usually translate to a better investment deal, which means that even with a large capital investment for a certain ECM, this may still be a good deal if the estimated savings are high enough.
There is not one set energy conservation measure/s that can fit all buildings. Though there can be rule-of-thumb estimates, it is still best to conduct an energy audit with building model simulation to see what ECMs would be most effective in achieving the desired cost savings.
To find out more about energy modelling and our consultancy services, check our our website at https://greensolutions.ph.