Air Conditioning Inspections for Buildingscourses.stroma.com/postaircon4/content/Training Slides...a...

.

Air Conditioning Inspections for Buildings

CIBSE TM44 Reporting Methodology

PRESENTED BYNIRAJ MISTRY

[email protected]

SA AC REGIONAL 1 © STROMA CERTIFICATION LTD V1.0

EPBD AC Definition

ALLOW TEMPERATURE TO BE CONTROLLED OR LOWERED

ALLOW TEMPERATURE TO BE CONTROLLED OR LOWERED

WATER AND AIR DISTRIBUTION

CONTROL HUMIDITYPROVIDE AIR

CLEANLINESS HEAT RECOVERY

SUPPLY AND EXTRACT

EPBD DEFINITIONINCLUDES

COMPONENTS WHICH PROVIDE:


AC System Types

Air conditioning systems with rated cooling capacities of over 12kW could be:

� Individual Split Systems;

� Multi-Split Systems;

� Distributed Heat Pump Systems;

� Centralised Systems.

� Where common control is present the cooling output can be considered as exceeding 12kW.


Guidance

BS EN 15240:2007, BS EN 15239:2007 & CIBSE TM44:2007

� Aimed at Article 9 implimentation.

� Guidance for accredited inspectors.

� For AC system capacities >12kW.

� Assessment and reporting methodology.


The Aim of the Inspection:� To provide building operators and owners with information regarding

building and plant performance.

� To identify opportunities for energy saving and hence operating cost

reduction.

Inspection to be carried out by visual observation of:� air-conditioning plant;

� refrigerant sight glasses;

� pressure, temperature or filter gauges;

� test readings where these are not available:

� BS EN 14511:2007.

Scope


Scope

Health & Safety Issues

� Inspectors have a duty to:

� Comply with relevant health and safety legislation.

� Draw building owner or manger’s attention to obvious instances of inadequate maintenance or neglect.

� Especially where these might have implications for the health and safety of the building occupants or members of the public.


Scope

Health & Safety Issues

� Inspectors must ensure that:

� They are familiar with current guidance concerning the health and safety implications of owning and maintaining air conditioning systems.

� Seek to satisfy themselves that adequate precautions and maintenance practices have been taken by the building owner or manager to minimise such risks.


System Efficiency

Assessment of Efficiency

� May require a complex process requiring considerable investment oftime, equipment and expertise; to obtain a good estimate of efficiency.

� Intended to provide a broad view of system design and operation.

� Addresses where this has been compromised.

� Does not put a numerical value on peformance.

� Include a view on the size of the system with respect to the cooling load, and on alternative solutions; as required by the EPB Regulations.


System Efficiency

Factors Affecting AC System Efficiency

� Operating efficiency is dependant upon:� inherent efficiency of the system;� state of maintenance;� effective control.

� Can be affected by efficiencies of:� refrigeration equipment that removes heat;� chosen refrigerant fluid and its charge within system;� heat rejection to atmosphere;� delivery of cooled air or water to, or other means of absorbing

heat from, the treated spaces;� any associated ventilation air supply and/or extract system.


Provision of Advice

� The provision of advice is required by the EPB Regulations, however no requirement to act upon this advice is required by the system owner or manager.

� The benefit of the inspection to the system owner or manager is the provision of appropriate advice with regard to:

� possible improvement or replacement of the air conditioning systems;

� alternative solutions that would increase efficiency and reduce energy consumption.


Inspection Preparation

INFORMATION MAY BE HELD OFF-SITE

INFORMATION REQUIRED FOR

INSPECTION?

SIMPLE PACKAGEDSYSTEM

CENTRAL SYSTEMS

SECTION 2.1

CIBSE TM44

SECTION 3.1

CIBSE TM44

INFORMATIONENERGY

CONSUMPTION

H&S FILES

F-GAS

PLANT ASSET LIST

BUILDING LOG BOOK

MAINTENANCE

INSTALLATION

O&M MANUALS


Extent of Inspection

Time Required for Inspection

Note: Risk assessment may be required for some tasks (e.g. examining inside ducts and AHUs) and should be carried out in collaboration with building owner or manager.

– Outside operational hours.

– Shut down systems.

SIMPLE 12kW SPLIT ‘PACKAGED’ UNIT

~ 2 HOURS

COMPLEX SYSTEMS

• INDOOR/OUTDOOR COOLING PLANT

• AIR HANDLING UNITS

• CONTROLS

• TERMINAL UNITS, ETC.

SMALLER INSTALLATIONS

LARGER INSTALLATIONS

> 1 DAY

> 2 DAYS


Extent of the Inspection

Inspection Sampling

INDIVIDUAL OR MULTI-SPLIT UNITS

MINIMUM OF 3 UNITS

+2 IF OBSERVATIONS INCONCLUSIVE

SERIES OF INDIVIDUAL OR MULTI-SPLIT UNITS

10% SAMPLE MINIMUM OF 3 UNITS

+2 UNITS IF OBSERVATIONS INCONCLUSIVE

COMPLEX SYSTEMS

• VAV TERMINALS

• FAN COIL UNITS

• ACTIVE CHILLED BEAMS

• ROOM HEAT PUMPS, ETC.

1 OR 2 UNITS

(OR ENOUGH TO SUFFICIENTLY EXAMINE STATE OF MAINTENANCE)

SMALLERINSTALLATIONS(FEWER UNITS)

LARGER INSTALLATIONS

>100 UNITS

2% SAMPLE (1 IN 50)


Energy

Consumption and MeteringLARGER ITEMS OF PLANT EQUIPMENT

ENERGY METERS/ HOURS RUN METERS

(IF RECENT WILL COMPLY TO ADL2)

CAN HELP

ASSESSMENT IF DATA HAS BEEN

RECORDED

METERS BUT NO RECORDS

RECOMMEND REGULAR

READING AND

RECORDING

INSPECTOR TO TAKE METER READING AND

LOG TIME/DATE

KEPT BY OWNER OR MANAGER

FOR NEXT INSPECTION

GUIDANCE ON METERING PLANS IS AVAILABLE IN CIBSE TM39

NO METERS INSTALLED

ADVISE OWNER/ MANAGER TO

REVIEW SCOPE

TO MOST ENERGY

INTENSIVE IF NOT ALL

SUBSEQUENT RECORDING OF

METER

READINGS

REGULAR ANNUAL CONSUMPTION

RECORDING

DEDUCE EXCESSIVE USE

PLANT RATED INPUT POWER

MORE FREQUENT CONSUMPTION

RECORDING

ALLOWS COMPARISON TO SEASONAL

EXPECTATIONS

IDENTIFICATION OF CONTROL ADEQUACY

AND/OR APPROPRIATE USE


Extent of Inspection

Existing Inspection and Maintenance Regimes

� Aspects of inspection could be simplified or reduced by evidence of a good practice programme of inspection and maintenance (e.g. filter/heat exchanger blockage).

� Refrigerant leakage should be checked for as may begin at any time and inspection may help identify potential leak.


Guidance

Good Practice Inspection and Maintenance

� Preparation of advice for building owner or manager regarding improvement of system performance or maintenance.

� Should include recommendation of scheduling frequent inspection and maintenance regime, where not present.

� Some users may not understand need for regular maintenance:� especially in non-critical applications;

� less experience of principles and equipment;

� unaware of responsibilities;

� may not realise consequences.

� May be combined with F-Gas and Pressure Systems Safety Inspections if inspectors are appropriately qualified.


Inspection Procedure

� BS EN 15240:2007 outlines the procedure for the inspections.

� Further guidance is available in CIBSE TM44.

� Packaged system procedure: split and multi-split systems.

� Centralised system procedure: larger centralised systems with plant rooms, water circuits, air handling and more sophisticated controls.


AC Systems

Packaged Systems

� Indoor units containing refrigerant-to-air heat exchangers and an integral circulation fan.

�Either integral with outdoor units containing refrigerant compressor, refrigerant to outdoor air heat exchanger and air circulation fan;

� or connected to the outdoor units by refrigeration pipework.


Packaged Systems

Figure 1.1 (Part 1) Summary of system types and their component parts (CIBSE TM44:2007).


Packaged Systems

Unitary Packaged Units� Indoor and outdoor components in self-contained

‘unitary’ package.

� Installed as ‘through the wall unit’.

� May be reversible heat pump.

� May have electric resistance heater.


Packaged Systems

Individual Split Systems• Also referred to as ‘split packaged units’.

REFRIGERANT CIRCUIT

COOLING

COOLING

INDOOR UNIT OUTDOOR UNIT

HEAT REJECTION

HEAT REJECTION

REFRIGERANT CIRCUIT


Packaged Systems

REFRIGERANTCIRCUIT

HEAT REJECTION

MULTIPLE

INDOOR UNITS

SINGLE or MULTIPLEOUTDOOR UNITS

Multi-Split Systems• Also referred to as ‘multi-split packaged units’.

DISTRIBUTION PIPES


REFRIGERANTCIRCUIT

Packaged Systems

Variable Refrigerant Flow (VRF) Systems• Allows variable control of different branches.

HEAT REJECTION

MULTIPLE

INDOOR UNITS

REFRIGERANT CIRCUITS(CAN HAVE VARIABLE FLOW)

BRANCH CONTROLMANIFOLD

SINGLE or MULTIPLE

OUTDOOR UNITS


Complex Scenario

Complex/Integrated Packaged Systems

� Extensive VRF systems:

� Multiple indoor units

� Multiple outdoor units

� Interlinked systems controls

� May require further skills to assess:� seek advice from more experienced inspectors, or those which are

familiar with centralised systems.


Centralised Systems

Refrigeration equipment delivers cooling via air handling unit(s) and/or pumped water circuits, which include:

� constant volume (CV) systems;

� variable air volume (VAV) systems;

� fan coil unit (FCU) or induction systems;

� active or passive chilled beam systems.

� Will incorporate more complex zoning;

� with more sophisticated controls strategies as appropriate.


Centralised Systems

Figure 1.1 (Part 2) Summary of system types and their component parts (CIBSE TM44:2007).


Centralised Systems

Constant Volume (CV) Systems

SUPPLY AIR EXTRACT AIR

FRESH AIRINTAKE

EXHAUST AIR

AIR HANDLINGUNIT

AIR COOLED

PACKAGED CHILLER

CHILLED WATER CIRCUIT

HEAT REJECTION

OCCUPIED SPACE


Centralised Systems

Variable Air Volume (VAV) Systems

FRESH AIRINTAKE

EXHAUST AIR

AIR HANDLINGUNIT

WATER COOLED

CHILLER

CHILLEDWATERCIRCUIT

SYSTEMCONTROL

MOTORISED CONTROL DAMPERS


OCCUPIED ZONE 2


OCCUPIED ZONE 1

T T


ZONE 1: VAV

Centralised Systems

Fan Coil Unit (FCU) System

FRESH AIRINTAKE

EXHAUST AIR

AIR HANDLINGUNIT

CHILLEDWATERCIRCUIT

BEMS SYSTEM

CONTROL

MCDs

CHILLER

CHILLEDWATER CIRCUIT

FAN COIL

UNIT

ZONE 3: FCU

T

ZONE 2: FCU

TT


Centralised Systems

Induction Systems� Air recirculation induced by pressure difference.

CHILLEDWATERCIRCUIT

CHILLER

OCCUPIED ZONE

T


Centralised Systems

Active & Passive Chilled Beams

PASSIVE

CHILLED BEAM

ACTIVECHILLED BEAM

OCCUPIED ZONE 1

OCCUPIED ZONE 2

SUPPLY AIR

CHILLER

Air supplied to chilled beams directly serving zones. Air is

conditioned at terminal units.

• Controls

• Positioning

• Design Philosophy

CHILLEDWATERCIRCUIT


Centralised Systems

Distributed Heat Pump SystemsWater loop/reversible heat pump systems

� Individual reverisble water-to-air heat

pumps linked to common heat injection

boiler and heat rejection cooling tower.

� Also known as ‘versatemp-type’

system.

BOILERHEAT

INJECTION

DRY AIR COOLERHEAT REJECTION

HEAT EXCHANGER


Combined Systems

� May have multiple systems per zone.

� May have multiple systems in building.

� Consider all present systems.

� Ascertain functionality.

� Observe systems.

� Sample from all systems.


Reporting

Part 4, Regulation 22 of EPB Requires:

a) address of the building in which the system is located;

b) the name of the energy assessor;

c) the name and address of the energy assessor’s employer, or if self-employed, trade name and address;

d) date on which the inspection occurred; and

e) the name of the approved accreditation scheme of which the energy assessor is a member.


Reporting

Required Details of the System:

� physical description of system;

� type of system;

� inventory of equipment;

� location of equipment and areas served.

Include comments on:� any results of any measurements or calculations made during inspection.


Reporting

Additional Advice

� Sources of good practice publications:� DCLG

� Carbon Trust

� DECC

� DEFRA

� CIBSE TM44 Reference List


Inspection Report


Reference Material

“Improving the energy efficiency of our buildings – A guide to air-conditioning inspections for buildings”, Department for Communities and Local Government, July 2008

“Health and Safety at Work etc. Act 1974”, Office of Public Sector Information

“Improving the energy efficiency of our buildings – Energy Certificates and air-conditioning inspections for our buildings”, Department for Communities and Local Government, 2008

“A guide for businesses – Reducing the energy usage and carbon emissions from your air conditioning systems”, Department for Communities and Local Government, 2007

“Fluorinated Greenhouse Gases Regulations 2008”, Statutory Instrument 2008 No.41, Office of Public Sector Information

“Inspection of Air Conditioning Systems”, CIBSE TM44:2007

Air Conditioning Inspections for Buildingscourses.stroma.com/postaircon4/content/Training Slides...a...

Documents

Transcript of Air Conditioning Inspections for Buildingscourses.stroma.com/postaircon4/content/Training Slides...a...