Tilt and Turn Window
Growing up in Germany, I am very familiar with the Tilt and Turn window. This type of window is the most common window in Europe. We had them throughout our house, and even as a child, I frequently used their multiple functions.
For those interested in the technical function of the Tilt and Turn, please continue reading below. For those who would rather hear stories about the Tilt and Turn, please skip the Technical discussion to End of Technical discussion, On to Stories!
The Tilt and Turn Window has three modes of operation. A lever on the side activates hardware concealed inside the window. When the lever is in the down position, multiple locking plates are engaged, and the window is locked tight with a complete air seal. When the lever is raised 90 degrees to the neutral position, the window will swing open to the inside, as an inswing casement. Finally, when the lever is rotated 180degrees to the top position, the window will tilt towards the inside, where it acts as a ventilator.
Each of the three modes has a significant function. To better understand the functions, I will define a couple of terms that will help make understanding the Tilt and Turn easier.
The Tilt and Turn is comprised of two major parts. The first is the sash. The sash is the hinged and moveable panel that holds the glass. Most of the operating hardware is built into the sash. The operating handle or lever is also attached to the sash.
The sash is attached to the second major part of the window, which is the frame.
The frame is installed into the wall, and does not move. The sash, through a series of ledges and gaskets, nests snugly inside of the frame. The unique tilt and turn hardware attaches the sash to the frame at several points. The hardware allows the sash to be either locked into the frame, swing out of the frame as an inswing window, or to tilt towards the interior as a ventilator.
When it is desired to close and lock the window, the sash is pushed by the lever into the frame, and the lever is turned to the down position. When the lever is rotated down, it activates numerous locking bolts which surround the sash, and which engage into corresponding locking plates mounted around the perimeter of the frame. With the lever down, the sash is effectively pulled tight into the frame, compressing each of the three individual gaskets, creating an airtight seal.
The multiple locking bolts are adjustable, so the installer can fine-tune the compression if necessary. Because the locking bolts are on all sides of the sash, the system cannot be penetrated. There is no way to pry a sash away from a frame without destroying the window. The security of the locked sash also means it has an incredible air seal, which is the most important consideration in energy efficiency.
It is this airtight quality that is the goal of the growing number of homeowners who are targeting energy efficiency. All three gaskets in the triple gasket system surround the entire perimeter of the sash. This creates both an air and watertight seal, greatly facilitating temperature controls within the home. When there is no air seepage and no thermal bridging, there is also much less transfer of heat.
Thermal bridging is another key term that we will return to when we discuss cladding.
The lever in the neutral position allows the window to swing on two hinges to the inside of the room. This has two distinct advantages over any other window.
The first advantage is that when opened, the window is protected from weather because it swings to the inside of the building. The leading cause for disintegration of windows is because they open to the outside, exposing the edges and hardware to rain or sun. Windows that swing to the exterior experience degradation such as warping from rain or snow falling on the sash. Damage from sun and wind is also common. These environmental problems are eliminated by the inswing Tilt and Turn window.
The second advantage of the sash that swings to the interior, is that the glass is accessible on either side. It doesn’t matter what floor the Tilt and Turn window is on, the homeowner can easily open the window to wash both inside and outside surfaces, mitigating the cost of professional cleaners. Especially significant are the cost savings where access to windows require ladders or rappel systems to clean.
The final component to the Tilt and Turn is the tilt mode. This is an amazing function, that facilitates better ventilating flow inside a building than any other type of window. The reason for this, is that when the sash is in the tilt position, because the plane of the window is penetrating into the inside air, a venture effect takes place. Outside air begins to mix with the inside air, creating a convective exchange of air. At any time of day or year, it is possible to tilt and ventilate the home. If air seems stagnant or stuffy due to cooking odors etc., put a couple of windows in tilt position, and witness the quick exchange of air throughout the room.
The window in tilt position is also still secure. The tilt is not far enough for an intruder to reach through the window. There are still many locking plates engaged, as well as top-hung hardware keeping the window secure in its frame. Furthermore, the handle cannot be rotated in the tilt position. There is a sash positioner that is activated once the window is closed. Only in the closed position, can the lever be activated.
Finally, in tilt position, it is possible to leave the window open during rain. Rain will fall on the glass, run down the window, and is then transported back outside of the window with a neat feature known as the rain apron. The rain apron is an extruded part that is mounted in the sill, to catch any drops of moisture, to redirect the water, and to protect the sill.
End of technical discussion, on to stories!
The reason I came up with the Tilt and Turn window, was that for years we had been making the European Overlay Door, the Lift and Slide and Slide and Fold, and I wanted to add a window to our line. Why not add the Tilt and Turn, Europe’s most popular window?
It was during the Recession, and cabinetry was becoming so competitive, that it was difficult to run a business making custom cabinetry in our area. I decided to focus on the products coming out of our shop that were unique to the local market, and unique to the American market in general. I invested in the tooling, which meant that I purchased the sophisticated cutting tools necessary to build these windows from Germany, and got to work.
Our shop shapers run the tools. We purchased four 3-phase industrial shapers to dedicate specifically to our European door and window products. We developed efficient organizing systems, so that we can quickly mount various cutters on the machines, and start building doors and windows immediately. This allows us to by-pass the expensive Computer Numerical Control (CNC) machines that convert computer programs directly to process. Instead, by lining up four and five shapers with dedicated cutters, we can replicate and exceed the efficiency of the CNC machine at a fraction of the cost.
The way we exceed the capability of expensive CNC machines, is by the flexibility we have in creating any size window or door we want, with little changeover time. The CNC machine will become important when we begin to create thousands of windows of programed size at one time. Also of importance to us, is keeping the operating and overhead costs to a minimum. This allows us to produce doors and windows of our type at a competitive price.
I made the first prototypes, and soon discovered that the exterior cladding was going to be extremely important. With a little research into what the best companies were doing in Europe, I discovered that to create a truly high-functioning window, we needed to create a window with no thermal bridging.
Thermal bridging is an important term in the discussion of energy efficiency. When trying to insulate an interior body from the elements outside, there cannot be any hard elements that transfer the heat or cold from outside to in. Think of a person climbing Everest Mountain: That climber has worked hard all day, she is exhausted, and badly in need of rest. She arrives at Camp 4, high up on the mountain, sets up her tent, and crawls inside to get warm. Climbers in high elevations will get into their sleeping bags immediately to preserve what body heat they have generated through their exertions, and to prevent rapid heat loss and hypothermia from the extreme sudden cold that besets the mountain once the sun drops.
Her sleeping bag has the highest possible content of fill and loft, which are the terms that describe the materials and the thickness of the sleeping bag walls. After taking her boots off, putting them in a dry bag so they don’t freeze at night, she slides in to her high-tech sleeping bag. Instantly the bag begins to work. Her body heat warms the inside of the bag. There is no heat loss, and since her body is a natural furnace, the bag continues to keep her warm throughout the night.
Climbers have to get inside their bags even before going to sleep. The climber will read inside the bag, converse and strategize with teammates from inside the bag, and cook from inside the bag. The bag is essential for survival in that environment. The bag works, because of the copious insulating materials surrounding the body of the climber. The bag works because it is a Thermal Barrier that is uninterrupted in any way. The heat source is inside, the cold is outside, there is no Thermal Bridging conducting the heat out, or the cold in.
Now imagine the same bag with numerous metal parts that allows the cold to penetrate! She would have a much less comfortable night! This same thermal bridging is what we decided to address in the construction of our window.
In the building of a window, there are lots of metal parts, metal fasteners, all of which can become bridges to bring the frosty exterior directly inside the home. We decided to address this issue. Using some of the European windows as models, we came up with the standoff metal cladding solution.
What I mean is that we wanted an air space between the metal, and our window, so we invented a system that holds the metal away from the wooden portion of our window through a series of nylon spacers. In addition, we use a non-metal composite spacer between the panes of glass for further insulation. There is no material that runs directly through the window. By creating the standoff cladding, the airspace causes the heat or cold to dissipate on the outside of the window. We have created the expedition style sleeping bag of windows. Let me tell you from the windows on our house, they really work!!!
Thanks for bearing with me with the discussion on the technical aspects of the Tilt and Turn, now I want to tell you a true story of how the Tilt and Turn has worked in our own home:
After providing our windows to clients for about four years, I finally had the time in the shop, and the resources to produce them for our own home. 15 years ago, we had done an extensive remodel of our home (a carpenters home is always in process, is it not?), and had put the best windows and doors available in at that time.
They were a high-end (shall not be named) wooden interior, aluminum-clad exterior window from one of the most esteemed window manufacturer in the country. They were mostly either outswing casement windows, or double hung windows, the most common window configurations in the US. Because of wet weather and sun, they had all failed, and were leaking miserably. In order to shut them for the winter, I had to go around to each window in the fall, push on the window to get it to seat in its frame, and have a helper throw the latch from the inside.
We even had to get ladders out to push the second story windows closed!
With great pleasure, I had my crew rip these window out, destined for the used building materials store.
Our new windows went in, with great care in the installation, so that the installation followed the same attention to thermal bridging that the windows did. Immediately we began to see their value.
We installed the windows in the summer, while the temperatures were still hot outside, and we wanted the house cool. In the mornings, we open the windows in their wide-open mode, to let the cool air flush out the entire house. Then we close them, so the highly efficient triple pane windows hold the nice cool air in. The house will stay the temperature of the imported air, which here in Colorado is a nice cool 60 to 65 degrees. Evenings as temperatures drop again, the windows go into tilt position for a beautiful airflow throughout the house.
In the winter we have noticed the following: The windows are so snug, there is an incomparable heat retention. Mornings, an outside/inside thermometer typically shows a 40 to 50 degree temperature difference, with far less heating required. An example of this is -3 outside, and 68 inside. On winter evenings, where we do a lot of cooking, or have people over and more bodies in the home, we will often have to tilt a few windows to let out some of the heat!
We know our windows are a success, and the function coupled with the high degree of craftsmanship and aesthetic beauty, will truly alter the feel of any home for the better!