Survey photography has certainly evolved through the past few decades and I can even remember lugging a bulky Polaroid camera onto the odd site. The photos were of awful quality, but they were instant, and usually quite adequate. I still have that Polaroid camera proudly displayed next to now obsolete cordless phones and other museum pieces. Of course it wasn’t that long ago when we took hundreds of photos with film cameras and fed the industry that was photo processing. I have written about digital camera use in the past and I still roll my eyes when I think back to my first device – it was manufactured by Kodak (of all companies – wow they dropped the ball) – and it also took awful photos, was about as big as the Polaroid, and I gave it away before long.
Proper surveying usually means judicious use of a long tape measure, propelling pencils, erasers, clipboards and all sorts of other paraphernalia. The likes of which are generally tedious to use, and fairly dreadful on a November rooftop. Most of us have similar experiences where we are hoping it isn’t raining, and if we are lucky the wind is not going to take our hard work away. It was nearly ten years ago when I first realized that you could actually perform the survey function with not much more than your smartphone. By about 2010 they were equipped with perfectly acceptable cameras that if used effectively, could give you just about everything you need to produce acceptable record drawings. There are some provisos to this of course – such as existing drawings that already lock-in the position of equipment and your task is just to update the drawings. So my first such project was the replacement of some exhaust fans on laboratory roofs – and all I did was to take many photos, take some pertinent measurements of existing equipment (which I typed into my Memo app on the phone), and proceeded to produce the tender drawings. All of this without the inconvenience of handling a clipboard and mini-plots on a cold and blustery day.
Things have moved on considerably from that experience. I have been involved with NRC Building S-77 on Sussex Drive in Ottawa since the early 1990’s. This heritage multi-storey building was modelled on Buckingham Palace which explains its magnificent facade. It has been a Science building from the beginning, and when I first became involved, its roof was literally covered with centrifugal exhaust fans serving labs below, typically exhausting fume hoods. Of course there were also about five major outdoor air replacement air handlers at roof level, and nothing to recover any of the energy loss. It’s best not to think too much about how much this place was costing NRC to run.
Jump forward to about 2012 – Ameresco were engaged to manage a complete energy refit of the building that not only upgraded the fume hood situation, but replaced nearly all of the rooftop exhaust fans with an extensive collector exhaust system – involving multiple large exhaust air handling units equipped with energy recovery coils. This energy is now transferred across to preheat the incoming outdoor air, and the cost savings are immense. The ducting systems were designed by a local engineering consultancy, and they were expertly installed by one of Ottawa’s leading contractors. The design drawings were created at 1:100 scale (don’t get me started), and the final installation matched the design in concept, but not reality. Unfortunately, a requirement for “as-built” drawings was not included, so NRC did not have accurate records of the many changes that ensued in the labs, or indeed of the extensive system now in place at roof level.
NRC Science labs can be busy places, and it is common for researchers to request larger spaces, which sometimes make themselves available. However just because a space is there for the taking, it doesn’t mean that the existing building systems can accommodate your requirements. A big concern was that even though exhaust risers were visible, the records of what exactly was connected to each riser on each floor were inadequate, and certainly not trustworthy. This is where Rodders CAS was brought on-board and I was given a contract to survey all of the exhaust risers and create riser diagrams for each and every one of them (there are hundreds). So I walked the site and marvelled at the extent of the exhaust upgrades on the roof, and decided there and then that what NRC really needed was a proper set of record drawings for the entire building, at 1:50 scale, that would show everything accurately such as the air valves serving the fume hoods, and the fume hoods themselves. This was not quite what I had been contracted to do, but it would have driven me a little crazy to have ignored the value of such drawings.
Back to Smartphone Surveying! It was of course late October, the weather was tending towards inclemency, and I didn’t fancy the idea of taking this on with a measuring tape. Of course I was able to survey all of the systems inside the building in comfort, so I started there. The answer was hundreds and hundreds of photos, and the golden rule became “keep snapping away” because digital photos are FREE. You soon learn that if you take a number of photos of the same ducting branch from different angles, you can locate it pretty well on the drawings. I had mini-plots of the original ducting layouts and marked these up as I went along. I kept wishing there was a way you could easily add a note to a photo you just took (never found one). I also realized early on that the first photo you take for a room system should be of the room number on the wall, outside the room. Otherwise you can end up with loads of photos and no idea what room they are from…
Eventually moving to the roof, and met with ominous clouds scudding across the sky, I set about recording the collector ducts. The riser duct penetrations through the roof were easy to accurately locate because the CAD for the floor below was trustworthy, showing the riser shafts. It took two survey sessions and almost a thousand photos; the roof is BIG, and it was fairly easy to lose your position, but a saving grace was that someone had thought to provide permanent metal riser tags that corresponded to the removed exhaust fan tag (thanks!). Taking photos from many angles was the key. Remember the client was not paying me to measure any of this – they wanted the riser diagrams. What they got was a full set of 1:50 as-built record drawings, and a separate 11×17″ PDF of each riser with all exhaust devices and an Excel table of (probable) airflows.
When finished I handed it all over and the client was more than happy. Back in the 90’s when I carried a pager, I used to say we need one device that does everything. My NRC S-77 surveys were achieved using a Samsung Galaxy S5, and I thought then that the photos were superb. Now I use a Google Pixel – and ducting never looked as good!