The mandatory air conditioning inspections and the subsequent reports that will offer advice to the building operator on how to maximise the energy efficiency of the system. In many cases the issues that impact an air conditioning system ’ s operating and energy efficiency can be fairly simply addressed. I thought it would be of interest and perhaps some amusement to illustrate some example of what the assessor might discover .
Design/Installation fault This is described as a design fault but equally it is an installation issue. It should have been realised that the cassette fan coil unit here is positioned too close to the walls (assuming the walls were there when the system was design/installed!). Here the cassette is not only installed so close to a wall that it will impede optimum discharge pattern of the airflow but in this case that discharge pattern will influence the room temperature sensor seen arrowed and result in control issues.
Design/Installation fault Again a system design fault but equally an installation issue. This inappropriate “internal positioning of what are designed to be outdoor air-cooled condensing units will starve the system of ambient air onto the condensing units and the restricted discharge will cause recycling. In this position the units would never operate efficiently in heating/cooling modes and unless urgently addressed will reduce the life of the compressors due to repeated stop start activity.
Installation error This Slide shows just how tight some installations can become. I am not sure how long the engineer on the left was trapped by his own handywork but I am assured that he was eventually extracated! In this case we have a technical problem that perhaps even a well qualified assessor might not even find let alone identify the fault. In the foreground you can se some insulated refrigerant pipework for a VRV/VRF air conditioning system. You may be able to make out 3 ‘ Y ”’ shaped sections - 2 in more or less a vertical plane and one over at an angle on the vertical. The problem is that they should all actually be in the horizontal plane or no more that 15 degrees either side of the horizontal. Applying to most VRV/VRF type systems, these are purpose designed branch joints that enable refrigerant flow to be smoothly diverted to different fan coil units or groups of fan coil units. They are designed to ensure a laminer flow with minimum turbulence. In the vertical or near vertical position this will create an oil trap and cause turbulence resulting in poor refrigerant flow to the fan coil units and consequently poor operational performance.
System Maintenance fault Coil Corrosion can quickly lead to significant reduction in cooling capacity. There are also signs that this condensing unit coil has never been cleaned, seriously impairing its efficient operation. The effect will be an increase in head pressure, which will translate to a reduction in the cooling capability.
Equipment installation This is not typical of what an air conditioning inspection will reveal as this a picture was obviously taken in the early stages of installation and before the completion of the building. However, its purpose is to show that it is common for equipment to become damaged during the installation process and have often been found in this condition long after commissioning. In this case we have a chassis style fan coil unit that will ultimately be enclosed behind an architectural or feature casing with a horizontal outlet grill. It is also extremely common to discover that no direct connection has been made between the fan coil outlet and the discharge grill.
System Maintenance fault A fan coil unit filter completely clogged with dust and debris. So simple to address but the effect is a reduced air flow due to resistance with a consequent loss in performance and/or an increase in fan power to overcome the added resistance. Not to mention the possible health consequences!
User error A heat source (computer) positioned by the user adjacent to the room temperature sensor arrowed will restrict or prevent the system from switching to heating mode and or keep system in cooling unnecessarily. Routine maintenance should pick this up and of course is relatively easy to resolve.
User error One of the most common problems where the efficient operation of fan coil units is compromised is by post occupation fixed and casual obstructions. Nice new offices don ’t usually come with convenient shelving! Potentially uncomfortable for the occupants but also the effect is a reduced (or completely blocked air flow) due to resistance with a consequent loss in performance and/or an increase in fan power to overcome the added resistance.
User error Of course if you really want to waste energy why not invest in air conditioning and then open all the windows! None of the illustrated examples are particularly uncommon and in most cases can be resolved relatively painlessly. However, as each and every one can lead to increased operating costs and in consequence the carbon footprint of a building, one might begin to understand what can contribute to unnecessary energy consumption statistics and why air conditioning inspections will serve to address this.
It is estimated that well over a third of all commercial air conditioning systems are more than 15 years old. This presents an opportunity to upgrade or replace old stock with more energy efficient modern systems - particularly where covered by the ODS Regulation which introduced use restrictions/bans on the use of ozone depleting refrigerants. Air conditioning inspection reports should advise on the serviceability of existing plant due to legislative restrictions Will introduce opportunities to clarify potential for energy efficiency improvements through replacement equipment. EPBD requirements are intrinsic to current Part L Building Regulations and will be extended in the ongoing revisions. There is a possible synergy with the Directive 2005/32/EC on the Eco Design of Energy Using Products still in the consultation phase. but which will be one of the most powerful Directives the EUP is expected to increase the effectiveness and synergies of all other EU legislation and initiatives concerning efficiency aspects of energy using products - particularly in the built environment
It is estimated that by the year 2010 well over a third of all air conditioned building areas will be more than 15 years old. This presents a great opportunity to upgrade or replace old stock - particular where covered by the ODS Regulation which Banned or introduced a phase out programme for the use of ozone depleting refrigerants. Air conditioning inspection reports should advise on the serviceability of existing plant due to legislative restrictions Will introduce opportunities to clarify potential for energy efficiency improvements through replacement equipment. EPBD requirements are intrinsic to current Part L Building Regulations and will be extended in the ongoing revisions. There is a possible synergy with the Directive 2005/32/EC on the Eco Design of Energy Using Products still in the consultation phase. but which will be One of the most powerful Directives the EUP is expected to increase the effectiveness and synergies of all other EU legislation and initiatives concerning efficiency aspects of energy using products - particularly in the built environment
Mike Nankivell Marketing & Business Development Director
Space Airconditioning plc
Is Energy Efficiency Up to the Measure? Energy Performance In Buildings Directive Article 9
Space Air HQ, Guildford 30 Years 1980 - 2010 Intelligent Distribution Largest Independent Distributor Guildford Birmingham Bristol Leeds Manchester SPACE AIRCONDITIONING plc UK DAIKIN DISTRIBUTOR
The CIBSE guide TM44 contains all of the information required for the inspections and includes:
Summary of system types
Suggested reporting format
DCLG Information Available from DCLG website http://www.communities.gov.uk/publications/planningandbuilding/airconditioning http://www.communities.gov.uk/archived/publications/planningandbuilding/airconbusinessesguide