Security camera report: Protective vents vs. desiccants
When condensation forms inside a security camera, it can
blur lenses and compromise image quality. Condensation
that remains within the enclosure can also corrode
electronics, causing premature failure of the camera. Gore
compared two IP66-compliant methods for reducing condensation: desiccant
within a sealed camera enclosure, and a protective vent installed in an
identical camera. Results showed that the protective vent was significantly
more effective at dissipating moisture over time. The vent also protected
the enclosure from seal failure and subsequent water ingress.
There are several conditions that will promote the formation of condensation
within a sealed security camera enclosure. These include exposure to
frequent or heavy rains, exposure to large daily temperature swings, sudden
temperature changes due to extreme weather, and repeated pressure differentials
that stress seals to failure, allowing moisture ingress.
Historical Approaches to Reduce Condensation
Initially, an open diffusion port (through-hole) in the camera enclosure was
viewed as a cost-effective way to dissipate interior moisture. These ports,
which readily allowed ingress of contaminants such as dust, sand, water and
other liquids, could not meet today’s IP66 standards for ingress protection.
Subsequently, sealed camera enclosures were adopted to meet IP66 requirements.
Since the sealed environment itself promoted the formation of
condensation, desiccant packs were introduced before sealing the enclosure.
However, desiccant packs have a limited effective life, and end-users
must periodically replace them. This can be time-consuming and costly,
due to the installation height of most outdoor security cameras.
Alternatively, a GORE protective vent can be installed over a throughhole
in the enclosure. The GORE vent provides IP66 protection against ingress
of particulates and liquids, while rapidly equalizing pressures, and
reducing condensation, within the enclosure.
These vents incorporate the proprietary technology of the GORE membrane.
Its microporous structure allows bidirectional passage of gas and
vapor molecules, while blocking ingress of particulates and liquids.
Made of 100 percent expanded polytetrafloethylene (ePTFE), the chemically-
inert GORE membrane is resistant to virtually all acids, alkalis and
detergents. It is also highly resistant to UV degradation, for extended service
life in outdoor applications.
The Study Methodology
Two identical outdoor security cameras were purchased. One camera was
left in its original state: sealed, with a desiccant pack inside. For the other
camera, the desiccant pack was removed and an adhesive vent was installed
over a through-hole.
Both cameras were mounted within a climate chamber, with each camera
powered and connected to the network under manufacturer-recommended
operating conditions. Each camera was focused on, and equidistant
from, its own target image.
Two separate climate chamber tests were performed:
- Test No. 1 compared image quality and humidity levels within the two
- Test No. 2 compared the effects of harsh conditions on the two camera
enclosures, and the related effects on camera function and reliability.
Climate Chamber Test #1: Comparative Image
Quality and Humidity Levels
This test employed a temperature and humidity cycle extending from
-15 °C / 0 % RH to 55 °C / 85 % RH. This cycle incorporated a 10-minute
water shower, to simulate rain.
Over the course of eight such cycles, we recorded images from each
camera, as well as the humidity inside each camera enclosure, in order to
monitor the levels of condensation.
As for image quality results, images captured during multiple subzero periods
demonstrate a dramatic difference in clarity. Image quality from the
camera with desiccant continued to degrade, as more condensation formed
on its lens with each cycle. By Cycle 8, the image is significantly blurred. Image
quality from the camera with the vent remained much more consistent,
because it did not experience a similar accumulation of condensation.
The recorded comparative humidity levels within each camera enclosure
also showed important differences. While humidity within both enclosures
increased in response to climate chamber conditions, the camera with
desiccant shows a significant increase, beginning at Cycle 6. This is because
the desiccant moisture-absorption process reverses itself after several cycles
of high humidity. At Cycle 6, the desiccant was fully saturated and began
releasing water back into the camera enclosure, creating the condensation
it was intended to combat.
Climate Chamber Test #2: Camera Reliability
Under Harsh Conditions
The objective of the second test was to compare the performance of the two
cameras under harsh conditions. The results were examined in terms of
their effect on the camera’s function, as well as their implications for camera
reliability over the long term.
For Test #2, the climate chamber was set up to reflect more challenging
environmental conditions. A 10-minute water shower was applied twice
daily to each camera enclosure, to simulate rain or pressure-washing.
The chamber remained at a constant temperature and relative humidity of
55 °C / 85 percent RH throughout this 10-day test.
During the 10 days, humidity levels remained consistent in the camera with the vent. In the sealed camera
with desiccant, humidity accumulated
quickly over the first three days,
and jumped dramatically on the
fourth day. From Day 4 onward, the
sealed camera with desiccant experienced
serious condensation, with
related degradation of image quality.
To understand the dramatic “Day
4” jump in humidity, it is useful to
examine the corresponding pressure
and humidity data for that camera.
After Day 2, pressure differentials
in the sealed camera diminished
dramatically. Subsequent examination
showed that the strong initial
pressure differentials had stressed
the seal to the point of failure.
The subsequent temperature
drops created negative pressure
within the enclosure, drawing ambient
air and shower water in through
the failed seal. The desiccant could
not counteract this trapped moisture.
Thus, excessive condensation
formed on the lens, seriously degrading
the image quality.
Of greater concern are the large
fluctuations in internal pressures
that are produced in totally sealed,
for example, non-vented, camera enclosures.
Such pressure fluctuations
cause severe and repeated stress on
seals, leading to premature seal failure.
This in turn allows ingress of external
contaminants and water, and
accelerates the formation of condensation.
This will degrade image
quality, and promote corrosion of
sensitive electronic components. Either
or both of these conditions will
negatively impact the performance
reliability of the camera.
Our tests demonstrate the performance
advantages of incorporating
a GORE protective Vent in security
camera enclosures. Results show
the GORE vent, which provided
IP66 level protection against water
and environmental contaminants,
dissipated moisture much more effectively
than the sealed enclosure
with desiccant. By reducing the severity
and duration of condensation
events, the vented camera enclosure
continued to deliver consistent image
quality and clarity over time. The
likelihood of condensation-induced
corrosion damage was correspondingly
Additionally, the vent provided
superior response to pressure differentials
caused by changes in ambient
conditions. Within the vented
enclosure, pressure fluctuations
were rapidly equalized, minimizing
stress on seals and the chance of
premature seal failure.
By protecting the camera’s image
quality and the enclosure’s seal
integrity over time, the installation
of a protective vent can effectively
enhance the long-term reliability of
a security camera.
This article originally appeared in the April 2015 issue of Security Today.