The advantages and possible further use of the developed monitoring tool were also discussed in the Task Force Workshop “Ventilation and AC inspections in Cold Climate countries” organised during the Annual Meeting. The presentation of experts from Nordic countries showed that there is a clear need for further practical guidance for member states – including the ones considered as more advances in this field, which have already implemented the EBPD regulation on the monitoring of AC systems. In the following REHVA Technical and Research Committee it was agreed that the AC Inspection Task Force will include instructions and guidance about the monitoring of AC system based on iSERV in its upcoming AC inspection Guidebook.

http://www.rehva.eu/publications-and-resources/hvac-journal/2014/032014/power-demands-of-heating-ventilating-and-air-conditioning-components-in-eu-buildings/

Power Demands of Heating, Ventilating and Air Conditioning components in EU Buildings

The importance of understanding energy use at HVAC component level

A previous paper in the January 2104 REHVA Journal (Knight, 2014) proposed that detailed monitoring of energy use at HVAC component level was likely to be a key element in achieving sustained reductions in energy use in EU buildings. To use this detailed monitoring to its full potential it needs to have benchmarks against which it can be compared, and Power Demand benchmarks are a key component for identifying Energy Conservation Opportunities.

The iSERVcmb project (www.iservcmb.info) is producing what is believed to be the first public dataset of measured energy and power consumption of HVAC components operating in European Buildings. This paper presents a brief overview of a subset of this data, normalised Power Demands, to illustrate some of the forthcoming outputs from the project this summer.

The Power Demands presented here are from measured data obtained during the iSERVcmb project. It was taken from 1700+ HVAC systems and components drawn from across Europe, which are servicing a variety of activities and floor areas. This measured data is a key element in the HVAC system benchmarking process proposed and tested by iSERVcmb across 16 EU Member States.

With such a large dataset it is inevitable that the data covers a wide range of years, and as such will continue to be analysed at finer levels of detail before the end of iSERVcmb to explore different ways of examining the data. However, the full dataset present at the time of this paper is used to provide the largest data source possible for analysis here.

Due to the analysis work still to be completed, this paper therefore provides only an overview of the ranges of Power Demands being found in practice by HVAC Component Type normalised by Area serviced by that component. Note that this floor area is derived from the iSERV spreadsheet and is therefore much more accurate than simply relating power demand to total building floor area.

Measured Energy Use by HVAC components

The iSERVcmb process philosophy is based around physically quantifiable parameters i.e. energy, space, activity types, and HVAC system components. A HVAC component could be, for example, a fan, pump, air handling unit, cold generator, etc. There are subcomponents of these component types…..To read the full article, download the attachment below.

The workshop allowed participants to take a world first look at the energy end use of HVAC components in practice across the EU. The aim of the workshop was to disseminate the final iSERV project findings with regard to HVAC system inspections, energy savings, IAQ findings, case studies, processes and practices. The workshop covered the following themes:

-Inspection of HVAC Systems through continuous monitoring and benchmarking

-iSERV, Inspection and Policy

-Parallel discussions about the deployment of iSERV results

-Use of iSERV Benchmarks

-Legislating for use of Intelligent Metering.

Hywel Davies, CIBSE’s Technical Director opened the workshop and welcomed all participants. After providing the audience with a short overview of the workshop, Prof. Ian Knight, Coordinator of project iSERV explained the background of energy consumption of HVAC systems in Europe, the iSERV methodology and highlighted the outcomes and questions arising from the project. He was followed by the BRE’s Roger Hitchin, who set the iSERV project aims and outcomes against the backdrop of current inspection practices and policies in the UK..

Subsequently, two roundtable discussions took place:

1) iSERV for HVAC system operators, manufacturers and owners

Group 1 was moderated by Prof. Ian Knight and was given a detailed presentation of the iSERV reports provided to end users participating to the project. Participants were primarily interested in the type and variety of benchmarks produced by the iSERV approach, the use of the building’s fabric and solar gain in the calculation of the benchmarks, the compatibility of building description data from other sources to the iSERV spreadsheet and the content of the iSERV reports. The topics that were discussed are presented in detail below:

Question from the audience:Can iSERV produce benchmarks that are more popular in commercial buildings:

•Energy use against occupancy

•Energy use against rental price sqm

•Energy use against G.I.A.

Response:The iSERV platform has the ability to produce these benchmarks. However this will require end users to provide more data about their buildings. In the life span of the project, we chose to restrict the amount of information required from the end users to the process of describing their building as a structure of spaces, HVAC systems and components. We hope that the iSERV benchmarks will act as a starting point to further discussion with stakeholders and project work that will allow for the production of additional benchmarks.

Question from the audience:Do the iSERV benchmarks and reports take into consideration the building fabric and solar gains?

Response:Within iSERV there is an allowance for gathering more information about outside conditions from internal building sensors in order to calculate energy signatures but the project deliberately does not consider fabric explicitly due to the unacceptable data demands this would impose during the project. Within iSERV the building fabric is treated as part of the Energy Conservation Opportunities. It is possible for iSERV to evolve to consider fabric issues if needed, initially by using assumptions regarding the building fabric based on the location, type and construction year of the examined building.

Question from the audience:Can iSERV provide conclusions on the range of savings deriving from oversized plants?

Response:iSERV is currently reporting electrical energy savings of up to 60% in individual systems and 5 – 33% were expected on average. Those savings have derived from understanding the building and improving system control. We do not aim at identifying oversized plants as something that is a bad approach; we are looking at producing ranges of what systems consume without differentiating between oversized and non-oversized plants. However, where installed load data is provided, we can examine the relationship between installed load, power demand and energy use.

Question from the audience:Going beyond legislative frameworks, what is the vision in using the information produced in the iSERV project?

Response:iSERV is hoping to contribute towards establishing standards regarding the collection and use of building services data. In particular, it hopes to provide an online benchmarking resource for such data which will be continually updated.

Question from the audience:Is there a way to automatically import building description data from to other platforms (e.g. BIM, TM22) to the iSERV spreadsheet?

Response:Although we recognise that such a feature would help in reducing the time and effort needed to fill the iSERV spreadsheet for those who do have building description data in other formats, this has not been part of the project’s scope. We hope that the iSERV findings with regard to building data collection and quality will contribute to the creation of relevant standards to reduce such hurdles.

Question from the audience:Does iSERV allow for the calculation of costs from operating specific HVAC components?

Response:The iSERV platform can provide end users with HVAC components running costs as long as the end user can provide a tariff unit.

Question from the audience:What are the expected typical costs to describe a building using the iSERV spreadsheet?

Response:The iSERV spreadsheet is an asset register that can be viewed as a time and cost investment. We have calculated a conservative cost of filling out the iSERV spreadsheet of approximately €1/m2 based on observations during iSERV.

Question from the audience:From the perspective of conducting inspections, how does the iSERV spreadsheet compare to TM44?

Response:The iSERV spreadsheet can be used as a detailed asset register to support TM44 requirements during inspections.

Question from the audience:What do the iSERV reports consist of?

Response:There are a number of standard reports contained within the HERO database. If these are not sufficient then bespoke reports can be designed according to the end user needs by logging into the HERO database and selecting the information to be included.

2) iSERV for legislators, policy makers, professional bodies & associations

Group 2 was led through the discussion by Roger Hitchin. The group agreed that the financial advantages of energy efficiency are valuable to all stakeholders; however if incentives were available in order to push end users to introduce more energy efficient measures, some inspector’s neutrality could be questionable by dint of financial reward. Moreover, participants suggested that the information deriving from inspections tends to be too technical for certain audiences. It was pointed out the iSERV approach shows savings to end users in a clear and understandable way that allows them to embrace it as they start to understand their buildings better.

Some participants proposed the iSERV method to be rolled out nationally in schools amongst which many have BMS or metering but no means of analysing the metered data. The iSERV approach could be applied not just for air conditioning but for all energy and water usage, benchmarked by type of school, as this could become a good transparent tool for bursars. For this to be achieved, participants agreed that it is crucial for BMS data to be compatible to the iSERV spreadsheet.

Overall the group concluded that the iSERV spreadsheet would be invaluable despite having to be completed by or with the help of a competent person and should expand to include more detailed lighting description, water usage etc. Most importantly, for an iSERV type of approach to become more popular there is a need for metered data to exist in open protocol and BMS terminology should be standardized.

+++

The scope of the conference will be to offer various stakeholders – researchers, industry, building owners, end users, consultants, engineers, architects, policy makers – a platform for the exchange of scientific knowledge and innovative technical solutions.
REHVA community endorsed and disseminated already the HARMONAC project and is looking for the learn about the final results about the H.E.R.O tool, HVAC system benchmarks across iSERV partner countries and the future exploitation of the online tool. iSERVcmb results will be presented by Ian Knight based on the final outcomes of iSERV partners joint work.

The conference programme and registration details are available in the REHVA website.

Public workshops for stakeholders (building owners and administrators, HVAC system designers, manufacturers and inspectors and legislators) are a key part of the iSERV communication strategy. The concept is to briefly introduce the work previously done, with focus on relevant tools and findings for the audience. Afterwards the participants are split into discussion groups, each supported by iSERV researchers, where they can ask questions and discuss about the applicability, ideas and concerns related to the project. This helps them to learn more about the methods used and at the same time they provide valuable feedback to the project team. Each internal iSERV project meeting is combined with such a public workshop.

Please register on www.iservcmb.info if you wish to attend and ask questions of the project team.

Author: Ian Knight (Cardiff University)

Recognizing that system and plant performance is a global issue this joint CIBSE and ASHRAE symposium will give a platform to best practice and research from around the world.

The annual Technical Symposium, now in its fourth year, encourages the participation of both researchers and industry practitioners at all stages in their career to share experiences and develop networks. It will explore both active and passive building systems that will shape an effective future for the built environment and maximise energy efficiency.

Professor Tim Dwyer, who has helped organise the Symposium content, says: “The Symposium will consider a range of topics that underpin the engineering assessment, design and operation of systems that integrate with the aim of delivering future cities that not only provide inhabitants with acceptable and maintainable conditions but strive to mitigate their environmental impact.

“We have seen part of this challenge brought into sharp focus over the past 12 months with continued urban density growth in fast developing nations and incidents such as air quality issues in China, political and consumer reactions to rising energy costs in the UK, and the resilience of buildings in the freezing weather conditions recently experienced in North America.”

Over 60 papers, posters and case studies will be presented in sessions covering:

• The effectiveness of systems in use.
• Evaluating the performance gap.
• The reality of setting ‘thermal comfort’.
• Measuring and managing energy use to reduce impact.
• Balancing energy use with user expectation.
• Mind the gap – modelling towards reality.
• Benchmarking to enable improved building design.
• Taking the heat off the grid – local heat and power systems.
• Assessing and delivering designs that aspire to nothing.
• The urban truth of delivering sustainable cities.

The event expands CIBSE President, George Adams’s Presidential address “Whole Life Thinking”. In this address he commented that engineers working in the built environment had an urgent responsibility to help reduce energy consumption and provide for adaptation of buildings and cities to respond to the challenges of climate change whilst accommodating the needs of rapidly growing populations.
http://www.cibse.org/index.cfm?go=events.view&item=4703

Author: Anastasia Mylona (CIBSE – Chartered Institution of Building Services Engineers)

In Supermarket stores more than one IAQ kit is not necessary in the way these stores are currently operated, except from the aisles with detergents, animal food etc., where VOC levels could significantly differ.

In some office buildings, IAQ measurements recorded lower levels of CO2 during operating hours in contrast with the higher levels that occurred during non – operation hours, due to the presence of people in the area, suggesting that the ventilation system works properly during normal working hours and not during the rest of the day which is necessary for the specific building. Moreover, the VOCs levels in most buildings were higher during non-operation hours, because of the emission of materials and the reduced operation of the ventilation system.

The results also showed that in most buildings regardless of the type, CO2 concentrations are higher during the winter season, due possibly to reduced ventilation rates to conserve energy or to more intense mobility of people at this period compared to the summer. In Supermarket stores a more stable trend of CO2 was observed, during the summer season, in contrast to the winter season where more fluctuations occurred. Furthermore, regarding VOCs, no relationship was observed between the pollutant and the corresponding periods in any type of building.

According to the physical inspections undertaken by MacWhirter Ltd, in most Greek buildings the operation of the A/C equipment, considering its type and age, would be deemed as satisfactory. Using the information gathered from the inspections, in some cases, the HVAC systems could be only radically improved by investing in the latest equipment, which might not be economically sensible. Results obtained so far from simultaneous measurements of HVAC parameters and IAQ indicated that a link between them depends on the use of the building, the maintenance of the HVAC system, and the age of the HVAC system. There was no clear link with energy consumption.

In conclusion, IAQ appears satisfactory in most buildings tested and there are no obvious links with energy consumption in the systems tested to date.

The Inspections allow the collection of data to establish if the iSERV prediction of performance is borne out by the actual operation and condition of the systems. The Inspections also allow us to identify any obvious defects or features that would give rise to the performances indicated, and to check that the description of system, activities and building corresponds to those in the iSERVcmb database.

We do not compare the Inspection findings to the monitoring at this stage, to prevent prejudicing the Inspection findings, but interesting trends have been found from the 44 inspections undertaken in United Kingdom, Greece, Austria, Portugal and Slovenia to date.

We have observed, for instance, a distinct contrast between Northern and Southern Europe as follows:-
Installed capacity
In Northern Europe, both Chilled Water and (Direct Expansion) DX systems alike often suffer from oversizing (with the attendant control and energy implications) – other than in perhaps the retail sector – by reason it seems of not appreciating or ignoring the need for basic room load calculations. In one case where a ‘one size fits all’ approach was used, this might not have been such an issue if inverter compressor models had been available at the time.
In Southern Europe, when there might have been overcapacity provided it was usually needed for flexibility of building/zone use. Multiple split DX systems were often installed which enabled load shedding, in contrast to using one large AHU, where by the fan input power would be excessive.
Maintenance
In Southern Europe maintenance visits appear to be more frequent, albeit they may be mainly minor inspections – monthly in respect of the retail sector and quarterly elsewhere. Whilst in Northern Europe, other than in the retail sector where monthly visits are the norm, the frequency of maintenance ranges from zero to twice annually. In parallel with our observations of far more issues with refrigeration systems in Northern Europe, this finding shows that the level of maintenance in Northern Europe should be re-assessed and both areas’ regimes would be enhanced if the ethos of the F-gas and ODS Regulations was embraced fully.

Visual evidence of refrigerant leak from an oil equalizing line on a compressor insulating jacket.
Energy Conservation Opportunities (ECOs)
Most of the Energy Conservation Opportunities flagged by the Inspections were found in Northern Europe i.e. four times as many as in Southern Europe. The main ones were:

• Maintain proper evaporating and condensing temperatures
• Consider modifying the supply air temperature (all air and, air and water systems).
• Replace or upgrade cooling equipment and heat pumps.
We can conclude, in general terms, that the Inspections to date reveal a wide range of operation of A/C systems, from good design, installation and maintenance, through to the other extreme. However, in all cases, the verification of energy efficiency in operation was most definitely absent.

Author: Dave Wright (MacWhirter Ltd)

iSERV has collected data from HVAC systems and buildings from 15 Member States of the European Union. This data, collected through continuous electrical monitoring, is then analysed so as to support end-users to improve energy efficiency of their own systems. That aim can be achieved by means of detecting different ECOs (Energy Conservation Opportunities) based on either real data metering or modelling.

A number of ECOs, capable of being addressed in this manner, have been selected and prioritised to offer an efficient financial ratio for the end-user in terms of investment and payback. These ECOs might consider e.g. the modification of regulation to adjust internal setpoints or HVAC system schedule. ECOs based on real metered data or modelling are used depending of the level of data available from the end-user and integrated within the HERO database (the online application tool of iSERV). Mathematical models have been developed and compiled for integration into HERO enabling automatic detection of these modelled ECOs for a specific building system. Approximately 15 ECOs modelled in this manner will be available at the end of the project to prove the concept.

Input requirements for modelled ECOs are mainly based on data available in HERO. For instance, if not available, power needed for lighting and appliances are estimated from activity (e.g. office building). Modelling ECOs are divided into two categories, depending on whether they need a monthly heating and cooling needs calculation. In the latter case, electrical consumption for HVAC system including auxiliaries is derived from heating and cooling needs.
The main Methodology used consists in considering a reference building case, which is pre-computed through the model core based on ISO standard 13690. Then the considered ECO is applied by varying one or more parameters, which allows assessing an estimation of potential savings (e.g. minimum savings, average savings, and maximum savings).
The following example illustrates the implementation of a simple ECO with high priority because of low investment and high payback.

ECO example: Shut off A/C equipment when not needed

Note: this ECO could be derived from the real metered data and/or from modelling depending on the level of data available for the considered HVAC system (i.e. with sub-metering or hourly data or not)
Definition
This ECO mainly aims to reduce energy used for the global AC system by applying an occupancy working schedule.
Action 1:
This reduction may apply by reviewing the operation schedule of the A/C system considering the building’s occupancy schedule. Thus the cold generator could be shut off during the unoccupied period, giving potential savings from:
• Night operation
• Week-end operation
Action 2:
Furthermore, the cooling equipment could be shut off during cold conditions, if it is not currently the case and if applicable (e.g. a data center needs cooling during the whole year).
To which systems does this ECO apply ?
This ECO could apply to any Air Conditioned equipment, including pumps when the cold generator includes pumps.

Tools
Model based on ISO 13790. Fully simulated ECO.

Pre-conditions : check & validation
• This ECO doesn’t apply if real metered data is available for the system. An alternative algorithm will assess the potential savings using the real data in this case
• AC equipment is working during unoccupied periods (night/week-end) and/or cooling is working during winter season
Description
1/ Preconditions check:
• Look at the schedule and occupancy to check whether the AC equipment is used during unoccupied period of the building (night/week-end).
• Check if AC equipment is working during winter season for cooling and check activity
Then, if pre-conditions are validated:
2/ The « ISO 13790 » core of the model is first computed with available data from the HERO database, especially schedules. Then the model is recomputed by reviewing the schedules:
a) Cooling/Heating schedule starts one hour before occupancy schedule and stops at the end of occupancy
b) If activity agrees (e.g. zone served by AC system is not a data centre), and if cooling is applied during winter, then cooling is considered capable of being shut off during the winter season.
Results
Results are expressed as a percentage of simulated energy savings.
Potential of energy savings:
• … % of cooling
• … % of global HVAC consumption
• … % of building consumption

Author: Julien Carton (University of Liège)

The results shown have arisen from the data monitoring of ten buildings. Systems monitored are the HVAC system, lighting, positive temperature and negative temperature cooling cabinets. The main sale area has refrigerated cabinets served by two centralized systems. Both systems have reciprocating electric compressors and are air condensed.
The buildings analyzed are served by all-air HVAC system based on rooftop units. Some buildings have gas boilers and air condensed chillers which respectively provide hot and cold water to the rooftop heat exchangers. In some case the rooftops have a gas boiler and an electric chiller onboard.

Yearly data show a moderate variability of global electric specific consumption among the different shops. The variability is high for HVAC and other systems, demonstrating that electric consumption could not be forecasted just based on square meter of sales area (other typical factors affecting consumption are occupation, climatic conditions and internal loads).

Monthly consumption analysis shows different behaviors for specific loads, depending on climatic conditions and working days. The lighting consumption shows an almost constant trend, demonstrating that the buildings analyzed do not have automatic control of light flux. Since the average consumption is about 86 kWh/m2 per year, the possibility to dimmer the lighting power in accordance with measured light intensity has to be evaluated. HVAC system consumption shows the highest variability, as expected, demonstrating that the systems control are working at least sufficiently, decreasing the consumption during the middle season. Two of the buildings analyzed show exceptionally high consumption during summer. The high consumption is related to the specific condition of the chiller units, which suggests an inspection and verification.

Lighting systems have shown in some shops an ineffective control during nights, as seen in figure below. Energy analysis requires hourly monitoring data to focus on the most promising energy efficiency measures.