| How
does the Megadoor withstand high wind loads? |
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The
Megadoor can be designed to withstand virtually any wind loading condition.
The principle is quite simple. The aluminum structural intermediate
beams between the two layers of fabric transfer the horizontal wind
forces to the guide rails mounted on the structural steel jambs provided
by the building supplier or, in the case of multiple leaf doors, to
the swing-up mullions provided by Megadoor. The design for the Megadoor
door leaf is similar to the design of a floor system. The influencing
factors are: |
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The
thickness of the intermediate beam web and flanges |
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The
depth of the intermediate beam |
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The
spacing between the intermediate beams. |
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Megadoor
has designed doors for wind speeds of up to 250 miles per hour. The
cost of the door system is based partially on the wind load requirements
and would naturally increase as the wind loading increases. |
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| How
is the door lifted? |
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The
bottom beam of the door is lifted by means of a belt or a wire rope
attached to either a belt or a wire rope hoist. To see the actual
operation of the door go to "Engineering Principles"
on the web page. |
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| How
long does the fabric last? |
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The
life span of the fabric depends on several factors. The UV exposure
is a factor with doors in Northern climates outlasting the ones in
the South. Doors in Southern climates could expect a life of between
15-20 years, and for Northern climates in excess of 20 years. Heavy
usage and some local environmental factors could also affect the life
of the fabric. Replacing the fabric is comparable to painting a standard
steel door system. On the average, the standard door painting would
have a life cycle of 5 to 7 years as compared to the 15 to 20 year
life cycle of the door fabric. Therefore, the cost of the fabric replacement
in comparison could be much less over the life of the door. |
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| How
does the fabric fade due to UV? |
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There
will be some dulling of the fabric color after a number of years,
but not as drastic as one might expect. We have several doors in place
in hot climates over 15 years that have maintained much of their color.
If fading is a big concern we suggest you go with the lighter color
fabrics such as white, tan and gray. |
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| What
about security with a fabric door? |
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The
door system is rarely the first level of security. It is obviously
possible to use a sharp object to cut through the fabric and enter
by crawling between the intermediate beams and over the bottom beam
that can be 18” to 24” in height: however, this is not
such a big issue in most situations. If your building has windows
or a door this would be the most likely place an intruder would select
instead of the cumbersome way of cutting through the door fabric.
There are motion detectors and other devices that could be installed
to detect unlawful entry into the building. We also have an option
for steel reinforced that could be suitable under certain conditions. |
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| How
much headroom does the door need? |
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The
headroom need depends on several factors: |
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The
total height of the door |
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The
wind load required |
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The
width of the opening |
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Swing-up
mullion requirement |
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If
you give us these specifications, we can easily calculate the exact
headroom required for your particular condition. As a rule of thumb,
a System 800 door requires 3-4 feet, a System 1000 requires 5-6 feet,
and a hangar door requires 5-7 feet, depending on the factors described
above. |
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| How
energy efficient is the door? |
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The
Megadoor is very energy efficient. A testament to that is the fact
that Alaska is one of our best markets. Our origin is from Northern
Scandinavia and the North Sea coast, so we are very familiar with
cold weather requirements. The main reason for the energy efficiency
of the door is the tightness. There is almost no draft coming through
the door. Studies have proven that approximately 80% of the heat
loss on a large door comes from air infiltration. So, a tight door
is more important than one with a lot of insulation.
The
air infiltration follows this formula:
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Leakage
(CFM) per leaf = (Total Door Ht. In feet) X (2) |
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The
R-Value is approximately 3.0. There is also another important factor
in hangar doors when the Megadoor is compared with the sliding door.
Due to the vertical operation of the Megadoor, it can be opened to
any height to accommodate a smaller airplane or other equipment. This
will save on heat loss inside the hangar by not depleting the heated
air and thus saving on recovery time |
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| What
happens if a belt or cable breaks? |
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The
Megadoor has a unique and patented safety arresting system designed
into the door. A stainless steel safety arrestor is attached to the
bottom beam of the door and would prevent the door from falling in
case of a belt, wire rope or hoist failure. The break works much the
same way as arrestors found on elevators. The safety arrestors are
cycled every time the door is operated ensuring dependable operation
in case of an emergency. We do, however, suggest annual maintenance
be performed to ensure dependable operation. The safety arrestors
are tested per the German "TÜF" Standards. |
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| How
would you operate the door in case of a power or motor failure? |
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There
are several ways the emergency operation could be accomplished. |
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Connecting
the door to a power generator would eliminate the problem in case
of a power failure. |
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A hand
crank that attaches to the output shaft of the motor is available
for manual operation. In cases of very large doors, this is not a
feasible way of opening the door. |
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A pneumatic
back-up hoist motor is available on certain doors. |
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Having
critical spare parts readily available in case of emergency |
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| How
does the cost compare to sliding doors? |
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The
Megadoor can be very competitive with standard steel sliding door
systems, particularly on the larger doors. The ancillary items required
for the sliding door usually offset any additional expense on the
structure required by Megadoor. In comparing the two door systems,
consider the following items that are not required by the Megadoor: |
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The
sliding door requires door pockets at one or both ends of the structure
or the inconvenience of blocking a portion of the opening preventing
full use.
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The
sliding door requires a concrete grade beam to support the door and
track system. This normally requires a multiple pour operation. |
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The
sliding door requires a top track system mounted to the structure
of the building. |
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The
manufacture and installation of the sliding door could require several
contractors for completion. The Megadoor is completely manufactured
and installed by Megadoor personnel |
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Please
contact us and we will be happy to send you a comparison. Just call
and give us the specifics on your project and we will do the analysis
for you. |
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| What
are the advantages over a sliding door? |
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There
are many operational advantages over the sliding door: |
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No need
for door pockets |
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Faster
operation |
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More
energy efficient |
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Open
any part of the door |
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No blocking
of opening |
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Fewer
bird problems |
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No bottom
track that collects snow, ice or debris. |
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| How
does the swing up mullion work? |
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Megadoor
has over 20 years experience with our electrically operated swing-up
mullion system. Click Here to view an animation
that shows the operation of the mullion. |
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| How
much does the door weigh? |
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The
weight of the door is dependent on several factors such as wind load,
door width and door height. It is less than most architect/engineer
expect. On larger hangars with wide spans the truss can normally carry
the weight on the door without any additional steel added. |
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| What
happens if you have a tear in the fabric? |
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It
is very easy to repair and can be carried out at the customers
convenience. There is rarely an emergency with a large tear in the
door fabric. |
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| What
kind of fire rating does the door have? |
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The
Megadoor does not have a fire rating; however, the door has a flame
resistant fabric that is self-extinguishing. We have various tests
made such as ASTME 84. |
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| Can
the door be made for explosion proof environments? |
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In
certain cases it is possible to use an explosion proof motor on the
door. We strongly recommend, however, that every effort be made to
avoid using explosion proof motors. They are expensive, not possible
to manually operate, and have a shorter life than regular motors.
In most cases we have found that the motors can be placed in a non-explosive
area on the opposite side of the door or above the ceiling area. Venting
the motors is another less expensive solution as well. |
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| Can
you put a man door into the door? |
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Absolutely,
we can do this by using a solid panel at the bottom of the door. It
will add to the headroom required for the door, but with some planning
the solid panel could go into a section of the door where the headroom
is not quite as critical |
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| How
much side room does the door take? |
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The
Megadoor takes very little side room - only about 4-6 inches in most
cases. It is critical, so please contact us and we can give you the
exact dimension. |
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