aerial photo of the building outlined in green
The building runs east west, so the windows are north and south facing. I had a mix of single and 28 year old double pane windows on the second floor of the building and we put triple pane windows on the north side because of the traffic noise, and double pane windows on the south with the extra reflective coating to reduce the heat.
The sound suppression of the triple pane windows has been extraordinary, so much so that I'll now have to put in a mechanical ventilation system in those offices because the tenants want to keep their windows closed for the quiet they offer, but need something for ventilation when the windows are shut.
And the summer heat reduction from the southern windows has been equally impressive.
Now we are into winter we are seeing the benefits of the insulating qualities of the windows. The building is heated with a gas fired hot water system but many of the tenants also used electric heaters to keep warm. No more!
Perhaps most dramatic of all is to compare this years hydro consumption to last year. The graph compares month by month hydro consumption for 2012 in dark blue, to 2013 in light blue, from June 1st to November 30th. See how hydro consumption in kWh used to rise in October as winter came on and now it does not.
Some of the success of the windows was that I was able to select from Milgard the windows that suited my needs instead of just going for the standard double pane windows - I used the triple pane for the noise off and the extra reflective on the south. In hindsight that was really smart, and I think the insulating values of the triple pane windows, even in our temperate climate, are not properly appreciated. I forget the actual difference between the triple pane and the double pane but I would do them again in a flash. I had been a little concerned on these north facing windows if they might reduce the light but that was not the case - what we found was a slight tinting of the light that was pleasant to the eye. And on the south side a receptionist who works with her back to the windows reported a lot less glare on her computer screen. The effect in the office is noticeable both in summer and winter. It is cooler in summer, and in winter the whole office feels uniformly warm and comfortable - there are no cold spots or drafts.
The only minor irritation with the windows was the drain holes were at the very bottom which made them difficult to caulk around - even a 1/4" lip to caulk to would have made a big difference! But that was a minor irritation (although very frustrating at the time!) when compared to how comfortable the windows have made these offices.
The key, I am convinced, is to take advantage of the customization Milgard offers with double pane and triple pane, and the range of coatings, and to select each window in a building separately according to its orientation and use of the room. With the choice you can offer, it is a waste for people to unthinkingly use standard double pane windows all around.