CTT | Humidity In Balance


When analyzing the benefits of the Zonal Drying™ System in operation, it has to be pointed out that all benefits cannot easily be related to Dollars and Cents, some benefits are also connected to passenger comfort and aircraft reliability. The main improvements experienced when operating an aircraft with the Zonal Drying™ System installed are:


– Increased Aircraft reliability
– Reduced aircraft weight
– Reduced fuel burn
– Lowered emissions
– No water or ice in insulation blankets
– Reduced change rate of insulation blankets
– Sustained insulation blanket performance
– No build up of fungus and bacteria in insulation blankets
– No “rain in plane”
– No wet seats or carpets
– No brown or fogging windows
– No frozen emergency exits or frozen emergency slides
– Less airframe corrosion
– Less rectifying work connected to corrosion
– Less electrical failures or arcing
– Less rectifying work connected to electrical failures or arcing
– Sustained or increased residual value of the aircraft

However the main issue is that; having uncontrolled water pouring around in an aircraft close to electrical wirings, electrical connectors and computers is not in line with operating an aircraft in a safe environment.

Lower fuel consumption. Less emissions. The less fuel burned the cleaner the atmosphere. Imagine saving up to 65 tons of CO2 – per aircraft per year! – as is the case with a narrow-body aircraft. Or up to 160 tons with a wide-body aircraft in regular service.

The calculations further back also show significant reductions of nitrogen oxides, hydrocarbons and carbon oxide.

Let’s calculate!

Example 1 Boeing 737NG – can save: 65 tons CO2*, 21 tons less fuel consumption* Reduced emissions – per aircraft and year: CO2 65 ton, NOX 190 kg, HC 35 kg, CO 460 kg

*Based on 3,000 flight hours per year. 200 kg less weight gives a fuel saving of 7 kg per flight hour with a 90% load factor, fuel efficiency factor of 3.5%. Source: www.luftfartsverket.se (Figures are approximate)

Example 2 Airbus A330-200 – can save: 165 ton CO2*, 52.5 tons less fuel consumption* Reduced emissions – per aircraft and year: CO2 165 ton, NOX 630 kg, HC 1 kg, CO 85 kg

*Based on 5,000 flight hours per year. 300 kg less weight gives a fuel saving of 10.5 kg per flight hour with a 90% load factor, fuel efficiency factor of 3.5%. Source: www.luftfartsverket.se (Figures are approximate)

Carbon dioxides (CO2). Contributes to the greenhouse effect that results in an increase of the earth’s average surface temperature. Nitrogen oxides (NOx). Contributes to acidification and over fertilization of land and water. Hydrocarbons (HC). Ground-level ozone that is created by reaction with sunlight can harm vegetation and affect human health. Carbon oxide (CO). Detrimental to human health.



The payback period is shortest for operators with high aircraft utilization and high passenger load factors. The values of operational reliability, passenger comfort and the effects on the environment are not even taken into account.Our calculations, based on experience from actual installations and reports from operators of our systems, show that the payback period for a Zonal Drying™ System in an aircraft can be as short as 1 to 2 years, depending on the type of operation and aircraft.

The competitive advantage

In terms of fuel: Up to 52 tons per aircraft and year.*

In environmental terms: Up to 160 tons of CO2 per aircraft and year. Not to mention other emissions such as: NOx, HC, and CO.*

In maintenance terms: Less downtime due to repairs, man-hours and material costs substantially reduced.

In terms of competitive strength: Better climate on board. Better work environment. Better adherence to flight schedule.

*in case of wide body aircraft

No matter how you look at it – installing a Zonal Drying™ System gives you a competitive advantage over airlines who keep their “rain in the plane”.

Less electrical failures.

Many of the electrical wires in the aircraft are located in the space between the inner lining and outer skin – right where condensation accumulates. This triggers warning signals and short circuits in sensitive equipment, resulting in delays and component replacements – if not worse.

Longer life cycle.

Corrosion mainly affects the areas around aircraft windows, doors, antennas and belly structures. Floor beams and electrical connectors are also exposed. This means extra expense for the airlines, since they often have to replace structural parts at D-checks. If moisture is removed, the risk of accumulating corrosion on the airframe is minimized.

No “rain in the plane”.

During take-off and landing, passengers and crew are often exposed to what is commonly called “rain in the plane”. Especially during descent or take-off, when water seeps along fissures in ceiling panels and people on board are exposed to dripping water. This is caused by water floating on surfaces on top of the overhead panels. It is condensed water that has not been drained out of the aircraft. This is not news. The news is that you can actually prevent this from happening.

Effective insulation.

Mould. The only thing that benefits from wet insulation. Condensed water permeates the insulation making it heavier and significantly reducing its insulation effect. When people on board feel cold draughts at windows and doors, this is one of the explanations. Also, since wet insulation is the perfect environment for mold, fungus and mildew, passengers as well as crew and maintenance staff may develop allergic reactions. During maintenace, parts of the insulation may have to be dried or replaced. This entails extra costs for the airlines, while still only providing a temporary solution to the problem – once the aircraft re-enters service the insulation will soon be soaked again.

A first indication of a wet plane is foggy windows.