D1.7: Measuring and diagnosis solutions for inspecting MEP/HVAC components
Research on measuring and diagnosis solutions for inspecting HVAC/MEP components concentrates on developing practical measurements protocols supported by hardware and software tools for self-inspection of HVAC/MEP components. Together with already presented protocols, presented by D1.6, the new protocols cover all phases of a building project (within the scope of the INSITER project). The main objectives of this deliverable are:
- To integrate the calculation and simulation methods (such as TRNSYS and Vabi Elements) in the BIM approach of the INSITER methodology;
- To define methods to determine the uncertainty of each key performance parameter measured and its impact on the global building performance;
- To define methods to determine thresholds for deciding on performance deviations of components and systems;
- To integrate the new approach in the quality control process.
From the research that is done in D1.1 (Best practices and shortcomings), D1.4 and D1.6 (Calculation and analytical methods for building & HVAC/MEP components) this document builds on the measuring and diagnosis solutions for inspecting MEP/HVAC components. D1.7 and its counterpart D1.5 for the building envelope cover the whole self-inspection techniques and quantifying methods for building and HVAC/MEP components. Findings from T1.3 have impact on the self-inspection process and thus also on the 8 steps methodology. Findings and related recommendations have been integrated in the self-inspection process.
Mass-production HVAC/MEP components
The most components of HVAC/MEP systems are mass-produced products. Generally speaking these mass-production components undergo very dedicated quality control processes. We talk in this case about prefabricated elements. Besides, complicated components and subsystems (such as heat pumps) are installed by dedicated teams including manufacturer specialists. They deliver well-functioning components including all requested inspection reports. The most crucial quality issues related to mass-production components are related to using proper settings and right mutual interaction between the connected components. These issues are, currently, a part of the initial commissioning (Cx) that has to be performed by the commissioning authorities; not by the workers themselves.
Current commissioning services are based on inspecting the work done by workers during construction activities. In the most projects, commissioning covers the stage between the end of the construction stage (including installing and mounting of HVAC/MEP systems) and the handover stage. According to services developed by DWA, commissioning is based on four pillars of inspection: quantity, quality, functionality and performance.
The INSITER project aims to increase building quality and energy performance through supporting workers faultlessly performing their work and properly self-inspecting the quality on solid basis. The new INSITER methodology strengthens the initial commissioning approach by re-structuring the inspection processes by the workers and supporting them by more self-instruction and self-inspection methods and tools. Besides, talking about responsibility issues, it is transferring more responsibilities tot workers during to the construction phase.
T1.3 builds up on already existing inspection and initial commissioning practices. It provides solutions to overcome difficulties in the current (self-) inspection and commissioning processes. Construction workers get better possibilities to improve their work and making the right decisions based on experience, software and hardware.
Difficulties in the current self-inspection process
Actual performance of the building and related HVAC/MEP systems (considering energy efficiency or building quality KPI’s) is a function of several factors including quality of building envelope/elements, performance of (all) HVAC/MEP systems (and all related subsystems & components), weather conditions and use & user influence. Therefore, functional tests in many cases depend on the completion of the system.
For example, the functional test of the control system must be largely completed and tested before being able to perform functional tests on the heat pump. Another example is the impact of seasonal/weather conditions and building occupancy on the actual performance of the HVAC/MEP systems. Therefore it takes, in the most cases, one year after delivery and occupancy to decide if the whole building, including all HVAC/MEP systems, is performing as designed.
There is thus a need to develop methods supporting inspection and decision making processes during the construction and self-inspection processes by the workers themselves.
In D1.7 as a part of T1.3, a simulation based approach has been developed to cover this performance gap.
A new diagnosis approach
D1.6, as a deliverable of T1.3, has already reported on self-inspection methodology based on insights from past experience. It contains lists of common errors and critical components. Workers can, herewith, effectively and efficiently self-inspecting components and subsystems. D1.6 provided also measurement protocols and quantitative methods supporting self-inspection by workers. For performance measurements and evaluation of possible performance deviations a new diagnosis approach is developed based on simulation techniques.
The new approach is based on simulating (total) building performance using deviated performance of critical components/systems as input. By doing that, actual performance under measured deviations will be mimicked by simulation techniques. Figure 2 illustrates the use of simulation techniques for the new diagnosis approach.
The simulation step will be repeated using a range of performance deviations. This will result in a relationship between measured performance and its impact on KPI in target. This relationship can be visualised in a graph; a diagnosis diagraph. Workers use such graphs during self-inspection processes to decide on impact of possible deviation on building performance and if the measured deviation will be accepted or rejected.
Updating the self-inspection process
Simulation-based self-inspection is a valuable approach for the total quality control process introduced by the INSITER project. Together with Experience-based self-inspection and Monitoring-based inspection, performance gap between design and realisation can be closed (see Figure 3). However, the latter two are outside of the scope of the INSITER project.
The self-inspection process is integrated in INSITER’s 8 step methodology. This methodology describes a detailed procedure where newly developed methods, tools and techniques contribute to INSITER’s goal to close the gap between design and realization. Self-inspection on MEP/HVAC components takes place in different steps of the methodology and in different phases throughout the building process. Figure 4 illustrates an updated version of the 8-step methodology and related self-inspections.
All inspection revolves around the same concept: to eliminate errors that have major influence on a definite list of KPIs.
Because of the complex multitude of actions, INSITER’s methodology will follow a structural approach. This method follows a bottom-up concept of eliminating errors. The levels of inspection are defined as ‘components’, ‘subsystems’, and ‘systems’ van bottom to top following::
01. Prevent that damaged or polluted components are installed;
02. Prevent that wrong components are installed;
03. Ensure that components are installed incorrectly;
04. Ensure that components are provided with the wrong settings; and
05. Ensure that components properly interact with each other.
The new approach is applied, where possible and valuable, in Chapters 4, 5, 6 and 7. Just like D1.6, D1.7 considers four leading MEP systems in the building, together covering for over 90% of all MEP systems with a relation to indoor environment and energy usage. These systems are: Heating & cooling (with heat pump); Mechanical ventilation (with heat recovery); Solar hot water and LED Lighting
The diagnosis solutions have been applied for the four HVAC/MEP systems in Section 4, 5, 6 and 7. The new simulation-based diagnosis approach is only applied to the COP of the heat pump because of the complexity of performance measuring of the heat pump. The INSITER project concentrates only on solutions that support workers performing self-inspection processes without burdening their process. Issues related to the applicability of the approach and related limitations have been extensively discussed.