Ok, to start then, lets look at the start of the energy auditing series.
1) Energy Balance.
Perhaps the one of the single most important aspects of an energy audit. The energy balance will identify about 80% of where your investigations will begin. As mentioned before this is very time consuming in terms of site visits and also desktop studies. The time invested in an energy balance can not be underestimated however and without this one would question the legitimacy of an energy audit. Suffice to say I have read some energy audits from the Carbon trust, written by so called CIBSE members that are are appalling and do not include an energy balance - how can this be from a CIBSE member?
Bloody shocking, but true. CIBSE is internationally recognised as the benchmark for Building Services Engineers. To me, the buck stops with CIBSE, pretty much what they say and their members is the fundamentals behind engineering, however, it is still possible to get shite energy reports from a registered member. The message is simple, even one of the most respected and regulated chartered associations has some that "slip through the net"
Anyway enough of griping (sorry to 99% of CIBSE engineers by the way) lets look at the energy balance in its naked form.....
The basics are simple -
- record every item on site that has an electrical consumption
- Through site investigation, experience and data recording, calculate electrical loads of the site
- Every electrical item needs to be recorded on site !
- calculate the phantom & running load of every electrical item
- The operational times need to be identified
- Staff and client population for the site needs to be identified
- Discover seasonal electrical trends
- Identify energy use types. E.g. Electric, gas, compressed air etc
- Start a 24 hour seasonal energy table - cross reference with half hourly data
- and so on.....
For example you may be in the process of an energy audit for a 30 storey high rise. This may seem daunting at first, but the same principles apply as if it where a 2 storey office complex.
- Record all electrical/gas/compressed air systems on site - tabulate your results.
- from the initial site visit, determine which processes require recording - i.e. data loggers
- installation of recording equipment - at the same time site interviews can be conducted
- group electrical items e.g, ICT equipment, lighting, HVAC, specialist equipment.
- start your spreadsheet !
- list the energy consuming groups against 30 minute intervals over a 24 hour period
- I usually start with the summer season. E.g in the northern hemisphere I will have my spreadsheet for energy consuming groups for mid month July.
So, this is your estimation of the running loads of each electrical group for example. This has been derived at by your site visits, your professional experience, data logging equipment, site interviews, information available from electrical retailers, etc, etc. This is NOT a best guess, it is data that you have arrived at by a number of evidential (quantitative) and experience/observations/interviews based (qualatative) measures.
Now, this is where you sort the wheat from the chaff, so to speak. This preliminary table is not complete...it needs to be benchmarked against the actual, in other words, you have to qualify your data interpretation further and review according to actual half hour data available from the retailer/supplier, and remember this is only one energy stream for one point in time in the summer season. You will need to formulate your energy balance for the winter & summer, for ALL energy sources....gettin the picture now?
Well, I was hoping to at least get this part of the energy balance completed on this post, but the other half is starting to "nag".
Till the next post then,
Snapa
