Filters & air cleaning units
Delivering efficiency through air intake screens
Daniel Betts explains how specifiers, building services engineers and facilities managers can reduce the energy consumption of HVAC equipment through essential maintenance
While it’s clear that effective
maintenance is essential for system efficiency, many companies leave it to the last minute and don’t see it as money well spent
28 | July 2014 | HVR
a study carried out by Johnson Controls in 2012, best practices in building mainte- nance and operations can reduce energy usage by 10 to 20 per cent, with poor maintenance increasing energy usage by 30 to 60 percent; startling figures that should make any company considering cutting their budget for related activities, think twice.
The study covered some of the main components of chiller and HVAC equipment in general, examining likely issues and the effect of an appropriate planned maintenance programme. Keeping centrifugal chiller tubes clean by appropriate water treatment, for example, can improve efficiency by 15 per cent if microbes are
eliminated, with this figure poten- tially going up to 35 per cent in extreme cases where iron deposits are present.
When the condenser flow rate is reduced by 20 per cent, full load energy consumption is increased by three per cent in mechanical and absorption chillers used in chemical process cooling. Common causes of reduced flow are partially closed or damaged valves, clogged hot-deck nozzles in the cooling tower, clogged line strainers, sediment in the condens- er tubes and air in the system. One of the key problems causing this ‘clogging’ is airborne particulates. This debris – leaves, dust, feathers and insects – can contaminate internal coil fins, per-
ishable filters and other compo- nents. Clogging restricts the move- ment of air, which means plant has to work harder to draw in its required airflow, using more ener- gy and therefore costing more money to run, with an increased risk of breakdown and downtime. To combat this problem, HVAC systems use filters, which are effec- tive to varying degrees and require changing on a regular basis. Pre- filters will last longer and need fewer changes, providing the strain on them can be reduced, but it’s important that they’re replaced according to pre-determined main- tenance schedules. Ignoring main- tenance periods of increased debris (between spring and autumn), can cover or ‘face-load’
Daily news update at
www.heatingandventilating.net
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40