In the summer, the windows felt like heating elements and was very unpleasant to sit near them. The air conditioner was overwhelmed and was unable to keep up with the demand for cooling. We expected some improvement in controlling the afternoon sun; but never expected the significant change that Koolshade made.
- BC Transit
THE MOST ASKED QUESTIONS ABOUT EXTERIOR SUN CONTROL SCREENS:
Q1. Why Put The Sun Control Screens On The Exterior Of The Windows '?
Sunlight is made up of short wave radiation. Short wave radiation will pass through clear glass windows virtually unchanged. There are some differences through tinted and or reflective glass or reflective film, but the principles are the same.
After the short waves pass through the glass, they will strike an object, such as people, drapes, furniture, walls and floors. These objects will absorb the short waves and then re - radiates them in the form of long wave radiation. Every type of glass is opaque to long wave radiation, and will not permit the heat to pass to the exterior, thereby trapping it. In most cases this solar heat will be removed from the building by mechanical equipment.
This entry of solar heat is the reason why a greenhouse works or why a car parked outside in the winter time, will get very hot inside, if the sun is shinning on the car windows.
An exterior mounted sun shade is considerably more effective than any type of tinted, reflective glass, reflective film or interior shading devios, in reducing solar heat gain.
Performance data on KoolShade is shown in the ASHRAE Handbook of Fundamentals. This reference book is used by all mechanical engineers when they are calculating solar heat gain through sun facing windows.
Q2. How Does The Buildings Owner Clean The Windows With KoolShade ?
The easiest way is for the window washer to use a power washer machine containing a dish washing detergent like ‘Cascade’. With the power washer the screens and the windows are cleaned at the same time and will drip dry, without the need for a squeegee.
The KoolShade screens could also be mounted using hinges or top and bottom tracks with the sun screens having top corner mounted nylon ball bearing wheels.
Q3. How Much Does KooIShade Sun Control Screens Cost '.?
Each project is priced according to the special conditions, unique to that particular building Items that effect the cost are: the number of stories, the use of a ladder, scaffold, swing stage or powered man lifts; the time of year or the temperature and weather conditions at the time of the installation can be a factor. Installation usually takes a little longer in very hot or very cold weather and 1’ or wet conditions; the method of attachment of the screens; the building's configuration, orientation and latitude; the quantity and the number of different sizes of the sun control screens, will also also effect the final pricing.
The screening comes in widths from 42" to 72" in 6" increments. If the screening width required, for example, is 43", then the job is priced based on using a 43" wide roll of screening. Waste can be a factor in the pricing.
The use of standard colours, as opposed to custom colours will effect the pricing. Screens with a sloped or curved top will cost more than a rectangular or square screen.
There will be exceptions, but almost any multi - storied building can receive KoolShade screens for a supplied and installed price of $22.00 to $30.00 per square foot of screening, in 2012 dollars. In every building project that I have been involved with, the cost of exterior sun control screens have been much less costly for both first costs and for operating costs, than for the cost or mechanical air - conditioning.
For example, the two, two story oflice building, where I installed KoolShatle sun screens to 4259 and 4299 Canada Way in Burnaby, British Columbia, the mechanical engineers, Sterling Cooper, had estimated that the cost to supply and install additional mechanical air - conditioning equipment to correct a serious problem of solar heat gain would cost about $350,000, and that the annual energy costs could increase by as much as $10,000. The end result was the KoolShade sun screens were installed for $200,000 and the building's owners, the Sun Life Assurance Company, reported a year later that their annual energy costs for these two buildings had dropped by $33,000,or about 33%.
This represented an saving of $150,000 and an annual saving of $43,000 in energy.
Q4. What Is The Life Expectancy Of Koo1Shade Screens ?
Under favourable weather conditions the screens have lasted 50 and more years on many buildings. In some sea coastal areas, with a high level of salt in the air, and in areas of high pollution, the life expectancy maybe reduced some what.
Q5. Will Koolfihade Sun Control Screens Reduce Glare ?
Yes, and I have installed KoolShade screens to several university buildings where glare and not solar heat gain was the problem- The screens corrected the glare problem.
Q6. Will KoolShade Sun Control Screens Reduce The Rate Of Heat Loss Through Glass ?
Independent tests have shown that if the screens are mounted within an inch of the glass surface the rate of heat loss can be reduced by up to 15%. This reduction in heat loss is achieved in two ways: First the screens will stop the glass surface from "seeing" the open night time sky, which usually has a lower temperature t:han the surrounding ambient air. Secondly the screens will reduce the rate at which the cooler night time air or wind, will "wash" the heat off of the glass surfaces.
Q7. Can The KoolShade Sun Control Screens Be Damaged ?
Yes they can, just as a glass window can be broken, a screen could be damaged. In my experience this hasn't happened very often. In one building, located in Oklahoma City, a severe hail storm broke many hundreds of window, in many buildings, in the city. The broken windows allowed rain to enter and caused severe water damage. On one building, with Koo1Shade screens, none of the windows were broken and just a couple of the screens were damaged and were quickly repaired.