Latest Findings

Latest Findings   Despite more than two decades of research, there is still not enough evidence to draw solid conclusions about duct cleaning’s benefits on indoor air quality, occupants’ health, HVAC system performance, or energy savings, according to a 2010 review of scientific studies on duct cleaning.1 The review did find clear evidence that ductwork can be contaminated with dust and can act as a reservoir for microbial growth under normal operating conditions. Yet, even when duct cleaning was extremely efficient at removing contaminants within ducts, the effectiveness of reducing indoor air pollutants was highly variable, and in many cases, post‐cleaning levels of contami

Operatives to commence

Operatives to commence cleaning of the ceiling. Cleaning to be carried out systematically ensuring that each area of ceiling is cleaned and any excess solution wiped off immediately from surrounding surfaces.
11  Operatives to pay extra care and attention where water or solution drips on to floors or may leak to basement areas below.
12  Operatives to rinse off cleaned section using clean water before progressing to next section.
13  On completing cleaning operations, operatives to descend from access equipment and carefully remove cleaning equipment back to floor level, observing safe manual handling techniques.
14  Operatives to carry out a visual check of the ceiling from ground level to ensure all areas have been cleaned as per the specification.
15  Operatives to dispose of all waste chemicals and materials on site and remove all cleaning equipment, chemicals and signage to company vehicle.
16  Operatives are not to leave the site until authorised by Supervisor.

Blind Cleaning – Metal

Blind Cleaning – Metal
1 Operatives to check all PPE, cleaning equipment and chemicals required for the task. Refer to COSHH assessments supplied for chemicals being used. Operatives to set out all ‘Caution/Warning’ signage required and cordon off cleaning area prior to work commencing.
2  Operatives to ensure that all furniture and trip hazards have been moved away from windows to provide a free access as possible. Team leader to perform walk through to ensure safe working and to identify any potential hazards. Please see site specific risk assessment on working with heights. Removal of blind
3  Operatives to erect access equipment e.g.. stepladder or ladder in the correct and safe manner. Ladders to be erected at the correct angle of 1:4 (75º). If working between 2-6 metres height ladders must be footed or an approved ladder stopper or stabiliser used.
4  Remove blind by loosening support screws. Team leader to ensure that two operatives are involved in removal. Cleaning
5  Remove as required and clean utilising a mystol dilute cleaning solution (diluted 1:10).  Back pack vacuum cleaner and brush systems may also be utilised

A serious concern

A serious concern in Florida is that the dirt that gets into air conditioning ducts often becomes caked and will be difficult to remove by cleaning methods currently available. When an air conditioner is operating, the air in the ducts is cool and saturated with moisture. Dirt particles exposed to this humid air take up moisture and can stick together and to surfaces in the ducts. Fiberglass lining in ducts make cleaning virtually impossible. The following comments were made at the Symposium, 1990 Indoor Air Quality in Homes: Synthesizing the Issues and Educating Consumers." In answering the question Can you minimize problems from furnace ducts by cleaning them?, Dr. Thad Godish2 replied: "A lot of fiberglass ducts are used, and in high humidity environments, they are going to trap organic dust which can result in mold and bacteria growing on them. In response to that, a number of companies are selling service which really is not going to do much good simply because the ducts get recontaminated so quickly. It is not possible for the cleaning to be as effective as it needs to be. One of the problems with fiberglass ducts is that they have a very rough surface which makes an excellent trap for dust. A lot of dust is organic dust, and if you have organic dust you are going to get the growth of mold and bacteria."

WHY IS IT IMPORTANT

WHY IS IT IMPORTANT? Studies indicate that 10%-30% of the heated or cooled air is lost—along with the money spent to heat or cool that air—through leaky ducts. Properly sized, installed, and sealed ductwork will make your heating and cooling systems significantly more efficient. Energy loss is not the only concern. Duct systems can also involve the comfort of your family, employees, tenants, or customers, as well as your indoor air quality. Testing the ducts will locate leaks or damage and focus repair work in the right areas. A properly operating heating, ventilation, and air conditioning (HVAC) system will help reduce overall energy use—especially during hot summer days when air conditioners are working harder and putting a strain on the electric system—and will deliver greater comfort and cleaner air to every room

major role

major role by using renewable energy as well as power generated by renewable energy sources such as wind and hydro.
The Tokyo Electric Power Company has been one of the forerunners in the use of heat pumps in several sectors of society. They led the way and played a key role in the success of heat pump and air conditioner use in Japan. In his keynote presentation, Mr Katsuhiko Narita discussed how heat pump technology has contributed to Japan’s modernisation. Being a Japanese champion in promoting heat pump technology, he described the entire history of heat pump technology, starting in the 17th century. During the last decade, global warming has become a major concern. Protecting resources and the environment is more relevant than ever, while at the same time, a growing number of people need to improve their living conditions, and the need for more comfort continues to grow. Humanity must reflect on how it uses its energy resources and on its commitment to sustainable development.
Mr Narita told the audience that against the background of future constraints on resources and the environment, heat pump technology will play a major role in the 21st century. He considers further improvement in heat pump technology and an expansion of its range of applications to the very realistic possibilities. Recent technical progress shows that air-source heat pumps can achieve a Coefficient Of Performance (COP) of nearly 6. This is the result of the so-called Top Runner initiative, aimed at improved equipment performance. More can and should be done to popularise heat pump technology in mature markets. It creates a pleasant urban living environment. Wider use of heat pump technology should be promoted as a matter of policy. A social system that effectively takes advantage of the diversity in time and temperature of its energy resources for heating and cooling buildings will be able to create a more pleasant urban living environment for its members.

Ground-source

Ground-source heat pumps Ground-source heat pumps have become a success story in several countries and climates, especially in colder regions. Market growth estimates range from 10 to 30% annually. Development of this technology has made significant progress during the past decade. However, further improvements in designing and reducing costs can be made. Reduction of initial cost has mainly been achieved through improved performance, which allows smaller, less costly heat exchangers, and more accurate design analyses. The conference devoted an entire session to this topic.
Ground-source heat pumps have not only seen significant market growth and broadened application; they are becoming recognised as a cost-effective standard for energy conservation. Key factors behind this success are soundness of the technology, improved design and installation infrastructure and the response of the heat pump industry. Current developments focus on five areas: • reducing initial costs of ground heat exchangers; • determining soil thermal properties; • modelling ground-source heat pump systems; •development of hybrid systems (ground heat exchanger combined with above ground heat rejecter/ absorber); • further development of design methodologies; •faster, lower cost pipe-joining methods; •new pumping configurations (variable speed, multiple and zoned on-off pumps).
In the US, there are three ARI certification standards, which rate so-called water-source heat pumps (water source, groundwater source and ground-source closed loop). The worldwide installed capacity and energy produced with ground-source heat pump systems is estimated at 6,675 MW and 23,270 TJ annually

compression cycle

compression cycle, which uses a rotary vane compressor with oil cooling, needs additional research and development. Given the large retrofit market potential for houses with hydronic heat distribution, scroll compressor manufacturers might do well to take up the challenge of developing specific products for this market.
Working fluids Much research has been and continues to be carried out in the field of new and alternative refrigerants and their application in air conditioning, heat pumping and refrigeration. Readers of this newsletter have been kept up to date on this topic. It might by now be superfluous to emphasise the importance of selecting the optimum refrigerant so as to achieve the design performance of a system under safe and environmentally benign operating conditions. It is obvious that the air conditioning and refrigeration industry have been impacted by environmental regulations to an extent not heard of before.
Under current circumstances, the conclusion is that no single fluid can be recommended as the best optimum solution for air conditioning, heat pumping and refrigeration systems. This means that designers are continuously faced with the problem of evaluating several refrigerants and trying to select the best one for any specific application. However, it is expected that in future environmental factors will increasingly influence the selection process.

is continuing its heat pump strategy

Vattenfall is continuing its heat pump strategy focusing on system efficiency, environmental benefit and economy for both the customer and the company.
Energy and environment Why heat pumps? Energy efficiency and environmental benefit are the key drivers for heat pump application and further research and development. A simple projection of world energy consumption and dwindling energy sources in the next decades shows that society faces a major challenge. There is a general awareness of this rapidly approaching problem, but society as a whole does not seem to be responding accordingly, assuming that there is sufficient time to find solutions. However, it is

The forthcoming

The forthcoming EU 6th Framework Programme contains several new major elements compared to previous programmes. A major new feature of FP6 is the aim to bring together a critical mass of resources and skills. New means of participating, with Networks of Excellence and Integrated projects will help to pool resources and increase focus on a reduced number of priority areas. This should help to create the European research area (ERA), which is an integral part of FP6. Universities, companies and research centres have responded to a call for Expressions of Interest and submitted more than 15,000 research ideas, including at least 4 on heat pumps. In an effort to promote partnering and collaboration, the commission will publish all expressions of interest over the summer on their web site http://www.cordis.lu/fp6/eoi-instruments/ home.html. An analysis of ideas received will be made public in September 2002 and will be used as input for drafting the detailed work programmes, which form the basis for the calls for proposals to be published at the end of 2002.

Program compliance

Program compliance of all subcontractors and making customers aware when work will be subcontracted • Customer approval of any changes from original estimate or installation design • Installing improvements to meet minimum program requirements for the installation of a heat pump; also, the QCN member is responsible for installing weatherization improvements in conjunction with the heat pump installed under the program to meet minimum requirements.  If an inspector determines that more than the minimum requirements were pre-existing, additional installed improvements will not be financed. • Providing quality workmanship performed in a workman-like manner in compliance with all specifications listed in the program guidelines • Submitting a detailed invoice of the heat pump installation, which separates costs for the heat pump, ductwork, weatherization, extended warranty, programmable thermostat(s), electrical upgrades, and/or other applicable and acceptable costs • Practicing good business ethics and ensuring customer satisfaction to best of their ability, including leaving the premises in a “broom clean” condition after the installation • Honoring all service and warranty commitments made to customers
Customer Responsibilities. Customers participating in the energy right Heat Pump Plan are responsible for: • Providing a copy of a deed or other evidence of ownership of the dwelling to meet a condition of financing eligibility under the program • Entering into an agreement with a member of the QCN for the installation of a heat pump  • Notifying the distributor to arrange for the loan closing or inspection • Ensuring that the heat pump is installed to the customer’s satisfaction • Signing the Work Completion Form after the work is completed to the customer’s satisfaction

A suitable, unobjectionable means

A suitable, unobjectionable means of disposal of the ground water source heat pump discharge water shall be utilized. This may include a natural stream bed, dry well, body of water, or a recharge system. The discharge cannot enter a septic tank, drainage field, sewer system, or flow onto the property of others. − The ground water source heat pump refrigeration system heating capacity, exclusive of resistance heaters, may be sized to meet not more than 100 percent of the heating requirements of the structure at the heating indoor design conditions stated in Equipment Requirements subsection, item 2, utilizing the manufacturer's published capacities for an entering water temperature (EWT) within 10 percent of the ground water temperature of the local area. The ground water source heat pump shall also be sized to provide a minimum of 100 percent of the sensible and latent load requirements at the cooling indoor design conditions stated in Equipment Requirements section, item 2; however, the total cooling capacity shall not be more than two times the total cooling load. The gallon per minute flow rate shall be within the range as specified by the manufacturer. A suitable means shall be provided by the contractor to determine the flow rate of the installed heat pump (i.e., flow meter or pressure/temperature test ports at the heat pump). 2. Earth Coupled Heat Pumps (ECHP) − The earth coupled heat pump refrigeration system heating capacity, exclusive of resistance heaters, may be sized to meet not more than 100 percent of the heating requirements of the structure at the heating indoor design conditions stated in Equipment Requirements section, item 2, utilizing the manufacturer's published capacities for an entering water temperature of 40°F (heating). − The earth coupled heat pump shall also be sized to provide at least 100 percent of the sensible and latent load requirements at the cooling indoor design conditions stated in Equipment

Heat Pump Plan Weatherization Standards for Existing Homes

Heat Pump Plan Weatherization Standards for Existing Homes
Attic Insulation
Applicability. Attic and ceiling insulation shall be installed when the existing effective insulation value is less than R-19 or when vertical walls surrounding conditioned rooms in the attic area do not have effective existing insulation.
Material Specifications for Blocking Materials. The following materials shall be used to provide any required blocking around heat-dissipating objects, attic accesses, pull-down stairways, chimneys, vent pipes from gas- or oil-fired appliances, etc.: • Mineral fiber batts • Sheet metal • Gypsum board (sheetrock) • Wood • Other materials approved by TVA prior to their installation

Support Materials for Floor Insulation.

Support Materials for Floor Insulation. In general, support materials shall be rot-proof, rust-proof, stretch-free and strong enough not to break when affixed to the underfloor structure. • When netting and staples are used as support, netting shall be knotted, looped, woven, or heat fused at all junctions; staples shall be the type commonly used to support insulation batts.  • Wire staves shall be made of a single piece of 13-gage (0.087 inch diameter) or larger “hard drawn” steel wire, pointed at both ends. Staves shall be manufactured especially for the purpose of supporting underfloor batt or blanket insulation.
Section 2C   01/16/2007
 16
• Staves shall be of good quality steel with sufficient spring to return to their original shape with little or no deformation when released.  • Wire staves shall have a length between 1/2 inch to 2 inches longer than the inside joist spacing on which the staves are used.  • When the wire staves are cut to a shorter length to fit smaller joist spacings, the cut shall be on a diagonal in such a way to produce a barb that will more easily secure the wire stave into the joist.  • Wire, nylon string, or other equivalent permanent materials of sufficient strength shall be used to support the insulation material.  • Nails with small heads, such as brads or casing and finishing nails shall not be used.
Installation Requirements. The QCN member for each weatherization item covered under Floor Insulation shall be responsible for ensuring that all materials used and work done comply with the installation procedures and criteria outlined in these standards. • Preparation Work—Work identified as preparation work shall be completed prior to, or in conjunction with, installing floor insulation.

Using manufacturer's

Using manufacturer's performance data, determine the water flow rate (GPM) and the heating capacity of the installation using the measured PD and the measured EWT.
e) Determine heating capacity by using the following formula: Btuh = TD x 1.1 x CFM TD =  temperature difference between supply air and return air 1.1 =  air properties constant CFM =  Cubic feet per minute air calculated, from funnel, temperature rise, or return air method
f) Verify that system capacity is + 10% of the equipment manufacturer's rating at the test conditions.
3) Check system cooling capacity as follows: (Major)
a) Allow system to operate for at least 15 minutes
b) Measure water pressure drop (PD) between water-in and water-out test plugs at heat pump. (Use same instrument to measure both to reduce error).
c) Measure entering water temperature at water-in test plug.
d) Using manufacturer's performance data, determine the water flow rate (GPM) and the cooling capacity of the installation using the measured PD and the measured EWT

Responsibilities Distributor

Responsibilities Distributor Responsibilities. Distributors participating in the energy right Heat Pump Plan are responsible for the following: • Arranging for all program-required inspections • Coordinating QCN member participation with TVA Customer Service Center personnel. If the distributor believes a QCN member participating in the program in their area has violated program criteria, the distributor may collect any evidence to support the claim, and may present such evidence to the appropriate Customer Service Center TVA personnel • Notifying all QCN members participating in the program in their service area of how the heat pump program will operate in their area, if any incentives or rebates are available and what percentage of inspections will be performed Contractor (QCN) Responsibilities. TVA will maintain a list of heat pump contractors who apply and qualify for membership in the Quality Contractor Network (a group of contractors listed by TVA). Only QCN members shall participate in the energy right Heat Pump Plan. If a QCN member, or representative, has any questions about weatherization measure(s), installation criteria, inspection procedures, or forms, the inspector should be notified prior to installation.

Switching

Switching off indoor fan during defrost (for units with a single compressor) This module provides the option of stopping the indoor fan during the defrost cycle. The option is only for cases where it is not possible to fit an auxiliary electric heater. - With the JP-19 bridge in place (as sent out from the factory) the indoor fan will continue operating during defrost. - With the JP-19 bridge open (jobsite modification) the indoor fan is switched off. Switch-off delay of the indoor fan (for single compressor units) The indoor fan will continue functioning for one minute more after the stop order. This uses up the energy accumulated in the inside interchanger and saves energy. This option can be deactivated at the jobsite, if preferred, by leaving the module JP-20 bridge open. Miscellaneous. - Connector for computer switching. - Possibility of lowering timer to 2 minutes. - Buttons

If the declared

Where Tj is the outdoor (bin) temperature and Tdesign is the lower temperature limit of the selected climate.
If the declared capacities of a unit matching with the required heating/ cooling demand the corresponding COP/EER value is to be used. This may occur with staged capacity or variable speed capacity units. If the declared capacity is higher than the heating/cooling loads, the unit has to cycle on/off. Then a degradation factor (Cd (air/air or Water/air) or Cc (others)) has to be used to calculate the corresponding COP/EER values. Cd and Cc can be determined by testing; else a default value of 0.25 and 0.9 respectively is used.  
The bivalent temperature, which is the lowest temperature when the heat pump can deliver 100% of the heat demand of the building, is necessary to use the excel sheet. The design heat demand of the building is a consequence of the stated bivalent temperature. The reference annual heating demand, kWh/a, is given by the product of the full load in heating Pdesign and the equivalent number of heating hours.  
The operation limit of the heat pump is set to the lower temperature limit for which the heat pump can operat

Introduction

Introduction The existing calculation tools for 1) design and 2) comparison need to be further developed to show the potential with new technology such as capacity controlled systems and more efficient system for combined operation with space heating and domestic hot water production. The overall aim is to develop existing tools for future needs. The outcome from the calculation tools should be useable for calculation of environmental impact. The purpose is to compare existing tools for calculation of seasonal performance factor and annual energy savings in order to propose needs for further development. For validation of the calculation tools existing data from laboratory and field measurements will be used. Seasonal Performance Factor, SPF, is a term used mainly for real installations, compared to the Coefficient of performance, COP, which is evaluated in controlled lab environment. How SPF is estimated depends on the situation under which it is evaluated, see Figure 1 below

shows an air supply

Figure 5 shows an air supply duct arrangement to distribute the 2137 cubic foot per minute air flow to the rooms of the building in proportion to the heat gain in each room.  The flow quantities are shown at each outlet diffuser. Since the pressure available is .2 inches of water and the pressure loss at each outlet diffuser is assumed .04 inches, there is .16 inches of water pressure for the ducts.  The ducts will be sized to make the total pressure loss equal in each run.  Lengths of each duct segment are shown in feet.  Additional length must be added to each run to account for losses in elbows and the entrance at the air handler.  From Reference 2 the entrance is found to be equal to 10 feet of straight duct and the elbows equal to 35 feet. Duct sizes will be found for round and rectangular shapes.  Equivalent round and rectangular ducts can be found in Reference 1 or online at the website

Aguide listof

Aguide listof tests to perform mightinclude the following: •What are the symptoms? The study should specify the type of discomfort experienced by occupants,such temperature,dust,smells etc.Their reactions require analysis to identify the cause ofdiscomfort. •Where and when does the problem occur? The frequency of problem needs to be identified,intermittentor constant,to detectthe contamination source. •How is the building maintained? •How is air distribution managed? Is itefficientand with sufficientair replacement? • Are the air handling units working correctly? Equipment needs to be inspected to determine if batteries, filters and humidity systems work correctly and are properly maintained. Excessive humidity is especially relevant. •Is supply air properly filtered? Are fans positioned correctly? •Are there any irregular indoor contamination sources? • Is building use consistent with that intend in the initial design? It is important to check that decoration materials,furniture and working material (printing and copying machines for instance) arenotasourceofexcessivecontamination.
Although Indoor Air Quality issues are usually due to some of the above,contaminated ducts can also be a sourceofproblems.Thatis why the interior of the ducts has to be carefully inspected.
However,two importantpoints should be noted:
•Mould will notdevelop inside ducts unless specific conditions of dirtand humidity exist. •Adustlayer may occur on the inner surface (in contactwith airflow) of all types of ducts,including metal ones.However,if the inspection reveals the presence of more than a thin layer,itis time to clean the duct.
Personal Protection
During inspection the HVAC system should be switched off.To prevent potential exposure of the building’soccupants todirtor cleaning products,the cleaning teams have to proceed with caution (and whilstatwork,wear gloves,eye protection and masks).

After the stable

After the stable reading the display will show “PASS” then revert to the
weighing mode. If the calibration does not pass the display will show “FAIL”
and shut off.
7) The calibration is now finished. If the calibration is correct, the display will
show the weight value.
NOTE: If the calibration fails retry, if it still fails then there may be damage to the
mechanics or an issue with the power. If you do not follow the procedures in a
timely manner the machine will automatically switch off and the calibration will
not be accepted. 6 | P a g e © Adam Equipment Company 2013
7.0 TROUBLE SHOOTING

Volume and Pressure of Air

Volume and Pressure of Air
The amount of air available to provide comfort to the rooms is determined by the equipment
selected to meet the loads of the house. In energy efficient houses with lower loads, properly
selected equipment will have less capacity to supply air, and the performance of the system is
dependent upon making the best use of the available air. The volume of air the equipment is
rated to deliver is determined at a specific pressure. Every item, including the ductwork used in
the airway, adds to the pressure loss within the system.
2.1.2 Ductwork Materials and Configuration
The ductwork that is used to achieve the delivery of air from the equipment to the room can have
a great impact on comfort in the room. The capacity of a duct to carry air is affected by the
resistance within the duct. Typical materials used to make up ductwork are galvanized steel that
can be formed into round or rectangular shapes, foil-faced fiberglass duct board that can be
formed into angular shapes in the field, or an insulated flexible fabric round duct. Due to the
varying friction factors of the different materials, the type of material must be considered in the
design process. Increased friction or duct length adds to the total pressure loss. Galvanized steel
material ductwork has a lower friction rate than that of flexible duct due to the smoother inside
surface of the steel duct; therefore, the fittings chosen will have a greater impact on friction
losses in the system. Because air travels easiest in a straight line, a turn in the ductwork will
increase the effective length of the duct by more than just the physical length of the turn. For
example, a 90° bend will add as much as 35 additional feet of effective length to a duct run,
depending on the construction of the ducts. Effective length values for common fittings are listed
in Appendix 3 of ACCA Manual D (Rutkowski 2009).

Fire closures

Fire closures of multi-blade design may be accepted provided they meet at least the following
design criteria:
 The fire closure shall consist of not more than 5 single plates, whereas the clear height of each plate
should be at least 20 % of the total clear height of the damper but not less than 200 mm.
 Each damper plate should have an overlap of at least 5 % of its height.
 A circumferential resting bar should be provided.
 Each damper plate should have a thickness depending on its cross section as specified in Table 1.2.
 The construction should be of robust design to avoid vibrations.
Prior to installation, drawings showing construction details of the multi blade fire closure have to be submitted
for approval. The construction is to be tested to the satisfaction of a GL Surveyor.
Special attention shall be paid to a regular service of the multi-blade fire closures.

Fire closures,

Fire closures/dampers
D.4.1 Fire closures at main inlets and outlets
D.4.1.1 The main inlets and outlets of all ventilation systems shall be capable of being closed from
outside the spaces being ventilated. The means of closing shall be easily accessible as well as prominently
and permanently marked and shall indicate whether the shut-off is open or closed.
D.4.1.2 Fire closures at ventilation inlets and outlets located at outside boundaries need not be of approved
type.
D.4.1.3 Fire closures, which are not of approved type, are to comply with the following requirements:
 The thickness of steel fire closures is shown in the following Table 1.2.
 If measures to increase the strength are taken, the thickness may be reduced with agreement of GL.
The construction of approved closures shall comply with the tested ones.
 The means of control is to be capable of being locked in open and closed position.
 When shut, the fire closures shall have close contact with a steel strip throughout their circumference.
All closures shall be easily accessible and capable of being operated easily and safely.
 Hinges and bearings of the fire closures are to be largely maintenance-free and easily accessible for
inspections and repairs.
 The controls and the "open" and "closed” position of the fire closures are to be clearly and permanently
marked.
 Power-driven controls and remote operated controls for fire closures must be provided with a second,
independent power-operating system or manual control operable from a safe position outside
the space to be protected or the closures are to be of fail safe type

Weathertight closing appliances

Weathertight closing appliances
D.3.1 Inlet and exhaust openings of ventilation systems are to be provided with easily accessible
closing appliances, which can be closed weathertight against wash of the sea. In ships of less than 100 m
in length, the closing appliances are to be permanently attached. In ships exceeding 100 m in length, they
may be conveniently stowed near the openings to which they belong.
D.3.2 For ventilator posts which exceed 4.5 m in height above the freeboard deck or raised quarterdeck
and above exposed superstructure decks forward of 0.25 L from F.P. and for ventilator posts exceeding
2.3 m in height above exposed superstructure decks abaft 0.25 L from F.P. closing appliances are
required in special cases only.
D.3.3 For the case of fire draught-tight fire dampers are to be fitted.
D.3.4 Weathertight closing appliances for all ventilators are to be of steel or other equivalent materials.
Wood plugs and canvas covers are not acceptable in these positions.
D.3.5 Closing appliances are to be examined and tested for weathertightness by water jet (from a
12.5 mm dia. nozzle and a minimum hydrostatic pressure of 2.0 bar from a distance of 1.5 m).
D.3.6 For special strength requirements for fore deck fittings, see D.2.2.
D.3.7 Rotating type mushroom ventilator heads are unsuitable for application in the areas defined in

Strength requirement

Strength requirements for ventilator pipes and their closing devices
D.2.2.4.1 Bending moments and stresses in ventilator pipes are to be calculated at critical positions: at
penetration pieces, at weld or flange connections, at toes of supporting brackets. Bending stresses in the
net section are not to exceed 0.8  y, where y is the specified minimum yield stress or 0.2 % proof stress
of the steel at room temperature. Irrespective of corrosion protection, a corrosion addition to the net section
of 2.0 mm is then to be applied.
D.2.2.4.2 For standard ventilators of 900 mm height closed by heads of not more than the tabulated projected
area, pipe thicknesses and bracket heights are specified in Table 1.1. Where brackets are required,
three or more radial brackets are to be fitted.
Brackets are to be of gross thickness 8 mm or more, of minimum length 100 mm, and height according to
Table 1.1 but need not extend over the joint flange for the head. Bracket toes at the deck are to be suitably
supported.

Minimum coaming heigh

Minimum coaming height [mm] for ventilators according to LLC 66 as amended
D.2.1.5 The thickness of ventilator posts shall be at least equal to the thickness of coaming as per
D.2.1.4.
D.2.1.6 The wall thickness of ventilator posts of a clear sectional area exceeding 1600 cm2 is to be
increased according to the expected loads.
D.2.1.7 Generally, the coamings and posts shall pass through the deck and shall be welded to the
deck plating from above and below. Where coamings or posts are welded onto the deck plating, fillet
welds subject of GL Rules for Hull Structures (I-1-1), Section 19, B.3.3 shall be adopted for welding inside
and outside.
D.2.1.8 Coamings and posts particularly exposed to wash of sea are to be efficiently connected with
the ship's structure.
D.2.1.9 Coamings of a height exceeding 900 mm are to be specially strengthened.
D.2.1.10 Where the thickness of the deck plating is less than 10 mm, a doubling plate or insert plate of
10 mm thickness is to be fitted. Their side lengths are to be equal to twice the length or breadth of the
coaming.
D.2.1.11 Where beams are pierced by ventilator coamings, carlings of adequate scantlings are to be
fitted between the beams in order to maintain the strength of the deck.

Ventilator coamings

Ventilator coamings
D.2.1 General requirements
D.2.1.1 The height of the ventilator coamings on the exposed freeboard deck, quarter deck and on
exposed superstructure decks in the range 0.25 L from F.P. is to be at least 900 mm, see Fig. 1.1.
D.2.1.2 On exposed superstructure decks abaft 0.25 L from F.P. the coaming height is not to be less
than 760 mm.
D.2.1.3 Ventilators of cargo holds are not to have any connection with other spaces.
D.2.1.4 The thickness of the coaming plates is to be 7.5 mm where the clear opening sectional area of
the ventilator coamings is 300 cm2 or less, and 10 mm where the clear opening sectional area exceeds
1600 cm2. Intermediate values are to be determined by direct interpolation. A thickness of 6 mm will generally
be sufficient within not permanently closed superstructures.

Special strength

Special strength requirements for fore deck fittings
D.2.2.1 General
The following strength requirements are to be observed to resist green sea forces acting on ventilator
pipes and their closing devices located within the forward quarter length.
D.2.2.2 Application
These Rules apply to all ship types of seagoing service of length 80 m or more, where the height of the
exposed deck, within the forward 0.25 L, in way of the item is less than 0.1 L or 22 m above the summer
load waterline, whichever is the lesser.Rules I Ship Technology
Part 1 Seagoing Ships
Chapter 21 Ventilation
Section 1 Ventilation
Edition 2014 Germanischer Lloyd Page 1–7
D.2.2.3 Applied loading for ventilator pipes and their closing devices
D.2.2.3.1 The pressures p [kN/m2] acting on ventilator pipes and their closing devices may be calculated
from: