| 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:
- The
thickness of the intermediate beam web and
flanges
- The
depth of the intermediate beam
-
The spacing between the intermediate beams.
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:
- The
total height of the door
- The
wind load required
- The
width of the opening
- Swing-up
mullion requirement
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:
Leakage (CFM) per leaf = (Total Door Ht. In
feet) X (2)
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.
- Connecting
the door to a power generator would eliminate
the problem in case of a power failure.
- 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.
- A
pneumatic back-up hoist motor is available
on certain doors.
- 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:
- 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.
- The
sliding door requires a concrete grade beam
to support the door and track system. This
normally requires a multiple pour operation.
- The
sliding door requires a top track system mounted
to the structure of the building.
- The
manufacture and installation of the sliding
door could require several contractors for
completion. The Megadoor is completely manufactured
and installed by Megadoor personnel
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:
- No
need for door pockets
- Faster
operation
-
More energy efficient
- Open
any part of the door
- No
blocking of opening
- Fewer
bird problems
- 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 customer’s 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 ASTM–E 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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