WHAT IS HUMIDITY?
Humidity is simply the moisture in the air. Relative Humidity is the amount of water contained in the air at any given temperature as compared to the maximum amount of moisture the air can hold at that temperature when saturated. 
For example, at 70°F, a cubic foot of air can hold up to 8.10 grains of moisture. If a cubic foot of air at 70°F contains 8.10 gains of moisture, it is said to be at 100% Relative Humidity. If that same cubic foot of air contains 4.05 grains of moisture at 70°F, this is compared to the amount of moisture that the air can hold when saturated at this temperature:
4.05 ÷ 8.10 = 0.50 (50%). Accordingly, this air is at 50 %RH (Relative Humidity).
The amount of water that a cubic foot of air can hold changes with its temperature, increasing as the temperature of the air increases. This is due to the fact that air expands as it warms and contracts as it cools. Accordingly, while a cubic foot of air at 70°F can hold up to 8.1 grains, the same foot of air at 0°F can hold only 0.48 grains of moisture. Therefore, if you have a cubic foot of air at 70°F with 50%RH (4.05 grains), as you cool this air toward 0°F, the air will reach saturation (100%RH) at 49°F and begin to rain (or snow) until you reach 0°F. Conversely, if you take a cubic foot of air at 0°F and 100%RH (0.48 grains) and raise its temperature to 70°F without adding any more moisture, you will end up with: 0.48 ÷ 8.1 = 0.6 (6%RH). This condition would be drier than the Sahara Desert which averages around 12%RH! This dry air is the cause of many IAQ problems.
WHY IS DRY AIR A PROBLEM?
When the outside temperatures fall below inside temperatures, as in winter, the result is that the cold, moist air entering the heated building becomes hot, dry air. In the same way that moisture in the air will be absorbed by materials in a building, this hot, dry air pulls moisture from everything it comes in contact with, trying to reach “equilibrium” (the point at which the material no longer loses or gains moisture). This “drying out” of the air is what causes the familiar problems of dry nose and throat, cracking of woodwork and materials, and static electricity discharges. This same dry air condition can also be caused by cooling the air below its dew point, thus removing moisture (dehumidifying), and then reheating it. This condition could occur in an air conditioning system or in refrigeration.
As an example of the problem: if you take wood from outdoors that has equalized with the outside air moisture content, into a heated building with a lower moisture content, the wood will begin to give up its moisture to the dry air in the building. As the wood loses moisture from its edges, the edges will shrink and pull apart creating cracks, or warping the wood. This same damage can occur with paper, textiles, some plastics, wax, porcelain, fruits and vegetables and other materials that have to ability to absorb or give up moisture. Such materials are said to be hygroscopic (water absorbing). Hygroscopic materials always seek to reach equilibrium with their environment.
In the case of a museum, where expensive paintings, sculptures and other hygroscopic materials are kept, rapid changes in Relative Humidity can be devastating and will eventually destroy the artifacts. In a printing operation, paper that is rapidly drying while running through a press, will shrink and curl causing jamming, tearing and even misregistration of printing colors. In a microchip wafer fabrication laboratory, slight changes in the dimension of a Silicon wafer can result in chips that are not usable.
Maintaining a consistent environment is essential for protecting hygroscopic materials from damage. Fluctuations in Relative Humidity throughout the year can be harmful, underscoring the importance of controlling and stabilizing it for Indoor Air Quality. This means regulating moisture levels by dehumidifying when the air is too damp and humidifying when it’s too dry. On a lighter note, it was fortunate to have chosen a venue for our cosplay, allowing us to revel in our costumes and flaunt our Best Halloween Contacts.
WHAT TO HUMIDIFY?
There are 3 basic questions that determine why an environment might need to be humidified. They are:
- Are there any hygroscopic (moisture absorbing) materials used either in the process or in the building?
- Is there any problem with static electricity?
- Is health and comfort a consideration?
Let’s consider these questions one at a time with some specific applications to look at.
1. Is there anything hygroscopic in the environment?
Hygroscopic is any material that absorbs moisture into the cell of the material causing a dimensional change. This is different from hydrophilic absorption which is absorption of moisture between the cells, usually NOT causing a dimensional change. It is the dimensional change of materials due to changing relative humidity that can have a more direct effect on the workability of materials and processes than even the temperature can. Some examples:
Printing: Paper arrives at the print shop in rolls, conditioned at the paper mill to a certain moisture content and wrapped by a vapor barrier paper to help retain this moisture (some of the reason for this is also because paper is sold by weight, and obviously it is cheaper to sell some water instead of paper). As soon as this wrapper is removed, the paper begins to lose moisture to the surrounding air if it is drier, or to take on moisture if it is moister. As the paper absorbs moisture its cells expand, and conversely shrink when giving off moisture. A single roll of paper can change dimension by several inches in width and length.
When a paper roll is placed on a press and begun to be unwound through the press, it will lose moisture very quickly. If multiple colors are being printed, these colors may print at the wrong places, causing “misregistration of colors” due to the changing dimension of the paper.
Many pressmen will adjust the rollers to compensate for this, but if the humidity changes during the day, then the adjustment of the rollers will need to be done quite frequently causing loss of paper, time and production speed.
The name of the game really is stabilization of the atmosphere. With proper humidity control, the paper will be stabilized, neither giving off or absorbing moisture and therefore not changing dimension. The result is faster speed, less downtime and also a reduction in the use of ink since less of the ink is absorbed by the paper itself.
Woodworking: Again, wood will shrink as it dries, causing cracking, splitting, checking and warping. Dry wood will also absorb the solvent out of finishes, producing a grainy, unglossy appearance. Likewise, glue joints will be unstable since the wood will absorb the solvent from the glue before it can cure properly. Again, stabilization of the atmosphere is the name of the game, so that the wood retains the same dimension throughout the process.
Textiles: As fibers are run through the looms, if they are dry, they will become brittle causing breakage, down time and reduction of production speed. A second side effect is that breaking fibers put lint into the air, often causing the air quality to deteriorate below OSHA standards. This is particularly important in cotton mills and asbestos brake lining manufacturing. Proper humidification reduces fiber breakage, the dust count in the air, and also results in faster machine speeds.
Offices: In offices, there is often expensive wood furniture, paneling, and carpets to be concerned about. Dry air in the winter will crack and warp desks and paneling. Carpets are made of fibers and as these dry out, they become subject to breakage from foot traffic. This increases the dust count in the air and also leads to premature wear out of the carpets.
Additionally, regarding indoor air quality, with proper humidification, several things take place. 1) The dust count goes down due to reduced fiber breakage, and also due to agglomeration of duct, causing larger particles to form that are more easily caught by filters, and because the filters themselves, which are hygroscopic, swell causing them to be more efficient. 2) Out gassing of materials is the other sick building problem, and since outgassing is nothing more than a function of the vapor pressure of the solvents, increasing the RH in a building can often reduce the rate of outgassing to a level more easily handles by the normal building ventilation rate.
Hi-tech Micro Chip Manufacturing: With today’s smaller and smaller chips, manufacturers are no longer talking about distances of microns, but rather, distances measured in Angstroms! Even a slight change in the dimension of the silicon wafer during photographic masking will result in a relative misregistration of the mask of over 100 miles.
Additionally, normal shedding of human skin in this environment can spell disaster. Relatively speaking, if a micro chip were compared to New York City, a single microscopic flake of human skin would crush Manhattan, The Bronx, Harlem, Queens and half of Long Island. Humidity control has become critical for hi tech manufacturing.
Investment Casting: We throw this in to cause you to consider not only the end product, but also hygroscopic materials used in a process. In the lost wax investment casting process, a wax mold of the part is first made and then dipped in porcelain. As the porcelain and wax dry and cure, if the air is too dry, the porcelain will shrink at a greater rate than the wax causing hairline fissures in the mold. When molten metal is poured into the mold, it will take up these fissures and this results in a nonrecoverable casting. This is the process used to make jet engine parts.
Museums: Obviously for the sake of expensive art and artifacts, proper stabilization of the environment is essential to long term preservation of many items. Painting canvasses that change dimension constantly will crack the paint. Any wood or parchment will be destroyed in short order when dry weather begins to crack them and make them brittle. In fact, some traveling exhibitions will specify the level of humidity to be maintained or they will not permit the exhibition to open.
Foods: Meats will retain their red color without nitrates, if they are kept in properly humidified freezer cases and storage. Once a vegetable or fruit loses enough moisture, the cell will “lace” or rupture, and thereafter, no amount of humidification will help, so it is important for foods to be humidified from the moment they are places in storage to the moment they are chosen by the customer.
Eggs will lose up to 50% of their weight if allowed to dry, since the shells are porous. At the hatchery level, this translates to a possible loss of up to 25% of new hatchlings. Also, as these hatchlings come out of the egg, very quick drying will result in sticking of the fuzz, evaporative cooling and death.
Animals: Zoos are acutely aware of proper humidification for apes and other animals. Dry air in the winter causes problems with the skin of these animals and also reduces their mating abilities.
2. Is there any problem with static electricity?
Static electricity is drastically reduces when the relative humidity is maintained above 35%. There are many industries sensitive to the problem.
Computer Rooms: Obviously, poor humidity control in a computer room results in the potential build up of static charges that can discharge, wiping out memory and circuitry components. Dry air and a secretary with an Angora sweater spell disaster to an IBM mainframe. High speed printers in computer rooms are also a source of problem because of the paper itself.
Printing: Aside from the hygroscopic paper used in the printing process, there is the static electricity problem.
Solvent fires are started in the ink wells of presses when static discharges ignite the vapors. A commercial newspaper press can develop up to 2,000,000 volts of electricity as the roll of paper is feeding off. This puts extra tension on the web as it moves through the press, but also can knock a truck driver on his butt if he gets too close!
Plastic Films: Plastic production needs humidity control to reduce static problems which causes the attraction of dust and also the usual problems of plastic films attracting themselves to rollers and machinery.
Photographic Films: Most commercial photo labs use humidity control to eliminate static discharge which can show up on films. This is particularly important when considering hospital x-ray films.
3. Is health and comfort a consideration?
Health and comfort haven’t always been the number one consideration of most employers, but with today’s litigious society, it is becoming more and more of an issue. Aside from the outgassing of materials and the reduction of duct by proper humidification, there is the fact that human beings simply feel better when nasal passages are maintained at a stable level.
Due to a reduction of surface evaporation on the skin by proper humidification, people feel warmer when the humidity is raised, often allowing the temperature to be reduced, saving on the heating energy normally required, and decreasing the heat loss gradient between indoors and outdoors.
Another source of problem in modern offices is the advent of soft contact lenses. Since these lenses are hygroscopic, they absorb and evaporate moisture from the surface of the eye. In a very dry atmosphere, these lenses will dry rapidly, causing them to curl, creating a very uncomfortable condition. Also, drying of the surface results in a sticky film which prevents the eyelids from properly cleaning the lenses during blinking. This sticky film allows faster buildup of proteins and bacteria and results in eye infections. In fact, a study of eye infections from soft contact lenses shows a marked increase in these infections during the winter months.
HOW MUCH HUMIDIFICATION DO I NEED?
Basically, you need to bring the grains of moisture in the air up to a level consistent with the desired relative humidity. Since this level is also dependent on the temperature in the space, we have developed a chart (following) which shows the grains of moisture in saturated air at any given temperature. The relative humidity needed is shown in the Table at the end.
Grains of water per cubic foot of saturated air (100 %RH)
From this chart it is easy to see how much moisture can be contained in a cubic foot of air at any temperature. For example, at 70°F a cubic foot of air will hold 8.1 grains of moisture at 100%RH. Again, at 50%RH that cubic foot of air would contain only 4.05 grains.
To determine the humidification demand load (how much humidification you need), follow these steps.
1. Determine the grains of moisture to add to each cubic foot of air to be humidified.
Example: Desired = 70°F/50%RH, Outside Air = 0°F/50%RH
a. From the previous chart, 70°F/50%RH = 8.10 grains X 0.50 = 4.05 grains/ft³
b. From the previous chart, 0°F/50%RH = 0.48 grains X 0.50 = 0.24 grains/ ft³
Grains to add to each cubic foot of dry air = 3.81 grains/ ft³
2. Determine the maximum volume of air to be humidified in one hour. Example: area is 200’ by 150’ by 25’ high, with 30,000 cfm of exhaust and 10,000 cfm makeup. Assume 1 air change by natural infiltration. (Use 1 air change/hour for most buildings, 1 ½ for a loose building, and 2 for a building with door opening and closing.)
a. Volume of area = 200 X 150 X 25 = 750,000 cubic feet/hour
b. Volume of exhaust = 30,000 X 60 min/hour = 1,800,000 cubic feet/hour
c. Volume of makeup = 10,000 X 60 min/hour = 600,000 cubic feet/hour
d. Use the largest of these volumes = 1,800,000 cubic feet/hour
3. Determine the basic humidification demand load formula:
The result of these steps is a lbs/hr load, which is the normal capacity rating of all commercial/industrial humidifier systems.
Obviously you would need to use a humidifier of this minimum capacity in order to reach the desired level of humidity.
Exceptions to the Rules
1. Economizer Cycle: In the case of an air handler with an economizer cycle, the maximum humidification demand load will generally (but not always) occur at the point where the economizer dampers reach 100% outside air intake. This is at the mixed air setting, usually 55ºF
a. Calculate the grains of moisture needed, as before, but this time deduct the grains of moisture available in the outside air, at the economizer set point.
b. Use the formula, substituting the full economizer CFM and the grains to add per set a. above.
c. Compare this to the other loads for the room size, and use the larger of the two.
Rules of Thumb
1. Computer Room A/C: Generally, computer room A/C equipment is designed to remove less moisture than standard A/C. The rule of thumb is 2 times the tons of cooling.
Example: a 20 ton computer room air conditioner needs 40 lbs/hr of humidification.
2. Standard A/C: Standard A/C generally removes 0.8 grains of moisture for every CFM of air over the coil. Example: 20 tons of standard air conditioning needs (20 X 400 CFM/ton X 60 minutes/hour X 0.8 grains) ÷ 7,000 grains/pound = 55 lbs/hr of humidification.
Loads Additions & Reductions
1. Product Load: If there is a large amount of hygroscopic material moving through the humidified area in an hour, it is then necessary to calculate the additional moisture that will be absorbed by this material, and add that to the humidification demand load. Example: paper production shipping 20 tons of paper per hour, starting at 3% moisture content and shipping at 5% moisture content; 20 tons X 2,000 lbs/ton X 0.02 = 800 lbs/hr of additional moisture must be added to the load. Use the following chart of product regains to calculate the moisture absorption of different materials.
2. People Reduction: People who are seated give off approximately 0.2 lbs/hr of moisture through respiration. Active people give off up to 0.9 lbs/hr. If there is an area with a large amount of people, this additional moisture may be used to reduce the humidification demand load. Example: 400 people X 0.4 lbs/hr (avg.) = 160 lbs/hr of moisture given off. WARNING: you should use a people reduction calculation ONLY if the people will be in area 24 hours per day.
3. Process Reduction: If there is a process giving off water vapor, the amount of moisture added to the atmosphere may be deducted from the humidification demand load.
REGAIN OF HYGROSCOPIC MATERIALS
*Example: If 1000 lbs. of writing paper passes from the equilibrium with air at 30% RH to the equilibrium with air at 40%, its water content increases from 5.2% to 6.2%.
- In air at 30% RH- 5.2% of the 1000 lbs. of water – i.e. 52 lbs.
- In air at 40% RH- 6.2% of the 1000 lbs. of water – i.e. 62 lbs.
This means 1000 lbs. of writing paper absorbs 10 lbs. of moisture when passing from the equilibrium with air at 30% RH to the equilibrium with air at 40% RH. For every 1000 lbs. of paper stabilized per hour, an additional 10 lbs/hr humidity load must be provided.
Reccomended Humidity Conditions For Various Industries
|
Industry |
ºF | ºC |
%RH |
| Abrasives Manufacturing | 78 | 25 | 50 |
| Bowling Alleys | 74 | 23 | 50 |
| Billiard Rooms | 74 | 23 | 45 |
| Bread | |||
| Flour & Powdered Product Storage | 75 | 24 | 60 |
| Fermentation (Dough) | 80 | 27 | 75 |
| Retarding of Doughs | 36 | 2 | 85 |
| Final Proof | 108 | 42 | 88 |
| Counterflow Cooling | 75 | 24 | 83 |
| Brewing | |||
| Hop Storage | 31 | -1 | 55 |
| Yeast Culture Room | – | – | 80 |
| Candy | |||
| Chocolate Pan Supply Air | 59 | 15 | 50 |
| Enrober Room | 83 | 28 | 28 |
| Chocolate Cooling Tunnel Supply Air | 43 | 6 | 78 |
| Hand Dippers | 62 | 17 | 45 |
| Moulded Goods Cooling | 43 | 6 | 78 |
| Chocolate Packing Room & Finished Stock Storage | 65 | 18 | 50 |
| Centers Tempering Room | 78 | 26 | 33 |
| Marshmallow Setting Room | 77 | 25 | 43 |
| Gum (deposited in Starch) Drying | 137 | 59 | 20 |
| Sanded Gum Drying | 1000 | 38 | 33 |
| Gum Finished Stock Storage | 57 | 14 | 65 |
| Sugar Pan Supply Air | 95 | 35 | 25 |
| Polishing Pan Supply Air | 75 | 24 | 45 |
| Pan Rooms | 78 | 25 | 33 |
| Nonpareil Pan Supply Air | 110 | 43 | 20 |
| Hard Candy Cooling Tunnel Supply Air | 65 | 19 | 47 |
| Hard Candy Packing | 73 | 23 | 37 |
| Hard Candy Storage | 60 | 16 | 40 |
| Caramel Rooms | 75 | 24 | 40 |
| Raw Material Storage | |||
| Nuts (insect) | 45 | 7 | 70 |
| Nuts (rancidity) | 36 | 7 | 70 |
| Eggs | 30 | -1 | 87 |
| Chocolate (flats) | 65 | 18 | 50 |
| Butter | 20 | -7 | – |
| Dates & Figs | 43 | 6 | 70 |
| Corn Syrup | 95 | 35 | – |
| Liquid Sugar | 78 | 25 | 35 |
| Comfort Air Conditions | 78 | 26 | 55 |
| Ceramics | |||
| Refactory | 13 | 55 | 70 |
| Molding Room | 80 | 27 | 65 |
| Clay Storage | 70 | 21 | 50 |
| Decalcomania Production and
Decoration Room |
78 | 26 | 48 |
| Cereal Packaging | 78 | 25 | 47 |
| Cheese Curing | |||
| Cheddar | 50 | 10 | 88 |
| Swiss | 60 | 16 | 83 |
| Blue | 49 | 9 | 95 |
| Brick | 63 | 17 | 90 |
| Limburger | 63 | 17 | 95 |
| Camembert | 56 | 13 | 90 |
| Clean Rooms & Computer Rooms | |||
| Computer Room | 75 | 24 | 50 |
| Clean Room-General | 72 | 22 | 45 |
| Clean Room-Critical | 72 | 22 | 45 |
| Distilling | |||
| Grain Storage | 60 | 16 | 38 |
| General Manufacturing | 63 | 20 | 52 |
| Aging | 69 | 20 | 55 |
| Electrical Products | |||
| Coil and Transformer Winding | 72 | 22 | 15 |
| X-ray Tube Assembly | 68 | 20 | 40 |
| Meter Assembly and Test | 76 | 24 | 62 |
| Fuse and Cutout Assembly & Capacitor Winding and Paper Storage | 73 | 23 | 50 |
| Conductor Wrapping with Yarn | 75 | 24 | 67 |
| Lightning Arrestor Assembly | 68 | 20 | 30 |
| Thermal Circuit Breaker Assembly and Test Water & Wheel Generators Thrust | 76 | 24 | 45 |
| Runner Hopping | 70 | 21 | 40 |
| Processing Se & Cu Oxide Plates | 74 | 23 | 35 |
| Fruit Storage | |||
| Apples | 35 | 2 | 90 |
| Apricots | 32 | 0 | 93 |
| Grapefruits (California) | 59 | 15 | 88 |
| Grapefruits (Florida) | 50 | 10 | 88 |
| Grapes (Eastern) | 21 | 0 | 85 |
| Grapes (Western) | 31 | -1 | 93 |
| Lemons | 59 | 15 | 87 |
| Oranges (California) | 42 | 6 | 88 |
| Oranges (Florida) | 33 | 1 | 88 |
| Peaches and Nectarines | 31 | -1 | 90 |
| Plums | 31 | 0 | 93 |
| Specialty Citrus Fruit | 39 | 4 | 93 |
| Fur Storage | 45 | 7 | 60 |
| Gum | |||
| Manufacture | 77 | 25 | 33 |
| Rolling | 68 | 20 | 63 |
| Stripping | 72 | 22 | 53 |
| Breaking | 74 | 23 | 47 |
| Wrapping | 74 | 23 | 58 |
| Hospitals | |||
| Operating, Cystoscopic & Fracture Rooms | 68-75 | 22 | 20-60 |
| X-ray, Diagnostic, and Treatment | 72-78 | 24 | 45-60 |
| Intensive Care Unit | 70-75 | 24 | 30-60 |
| ER Waiting Rooms | 70-75 | 24 | 45-60 |
| Leather | |||
| Drying | 95 | 35 | 75 |
| Storage, Winter Room Temperature | 55 | 13 | 50 |
| Lenses (Optical) | |||
| Fusing | 75 | 27 | 45 |
| Grinding | 80 | 27 | 80 |
| Libraries & Museums | |||
| Normal Reading and Viewing Rooms | 72 | 22 | 45 |
| Rare Manuscript Storage Vaults | 71 | 22 | 45 |
| Art Storage Areas | 68 | 20 | 50 |
| Manufacture | 73 | 22 | 50 |
| Drying | 72 | 23 | 60 |
| Storage | 61 | 16 | 50 |
| Meat & Fish | |||
| Beef (Fresh) | 33 | 1 | 90 |
| Beef, Fish, Lamb, and Pork (Frozen) | -5 | -20 | 93 |
| Fish (Fresh) | 34 | 2 | 93 |
| Lamb and Pork (Fresh) | 33 | 1 | 88 |
| Mushrooms | |||
| Sweating-out Period | 130 | 54 | – |
| Spawn Added | 67 | 20 | 100 |
| Growing Period | 54 | 12 | 80 |
| Storage | 33 | 1 | 83 |
| Oil Paints: Paint Spraying | 75 | 24 | 80 |
| Pharmaceuticals | |||
| Manufactured Powder Storage & Packing Area | 75 | 24 | 35 |
| Milling, Table Compressing, Coating | 75 | 24 | 35 |
| Effervescent Tablets & Powders | 75 | 24 | 20 |
| Hypodermic Tablets | 75 | 24 | 30 |
| Colloids | 70 | 21 | 40 |
| Cough Drops | 80 | 27 | 40 |
| Granular Products | 76 | 24 | 8 |
| Ampoule Manufacturing | 75 | 24 | 42 |
| Gelatin Capsules and Storage | 76 | 24 | 35 |
| Microanalysis | 76 | 24 | 50 |
| Biological Manufacturing & Liver Extracts | 76 | 24 | 35 |
| Serums | 76 | 24 | 50 |
| Plastics | |||
| Manufacturing Areas, Thermosetting, Molding Compounds | 80 | 27 | 28 |
| Plywood | |||
| Hot Pressing (Resin) | 90 | 32 | 60 |
| Cold Pressing | 90 | 32 | 20 |
| Printing | |||
| Platemaking | 78 | 25 | 45 |
| Lithographic Press Room | 78 | 25 | 45 |
| Letterpress, Web Offset Press Rooms, Paper Storage | 78 | 25 | 50 |
| Paper Storage (Multicolor Sheet Feed Lithography) | 78 | 25 | 6 |
| Rubber Dipped Goods | |||
| Cementing | 80 | 27 | 28 |
| Storage Prior to Manufacture | 67 | 20 | 45 |
| Laboratory (ASTM Standard) | 72 | 23 | 50 |
| Tea Packing | 65 | 18 | 65 |
| Textiles | |||
| Opening and Picking | |||
| Cotton | 78 | 25 | 62 |
| Man-Made | 72 | 22 | 53 |
| Carding | |||
| Cotton | 78 | 25 | 53 |
| Wool | 78 | 25 | 65 |
| Man-Made | 73 | 23 | 55 |
| Silver and Ribbon Lapping | |||
| Cotton | 78 | 25 | 53 |
| Man-Made | 73 | 23 | 60 |
| Combing | |||
| Cotton | 78 | 26 | 60 |
| Wool | 78 | 26 | 70 |
| Man-Made | 73 | 23 | 60 |
| Drawing | |||
| Cotton and Wool | 78 | 26 | 55 |
| Man-Made | 73 | 23 | 55 |
| Roving | |||
| Cotton | 78 | 26 | 55 |
| Man-Made | 73 | 23 | 55 |
| Spinning | |||
| Cotton | 78 | 26 | 48 |
| Wool | 78 | 26 | 53 |
| Man-Made | 73 | 23 | 57 |
| Winding and Spooling | |||
| Cotton | 78 | 26 | 60 |
| Wool | 78 | 26 | 58 |
| Man-Made | 73 | 23 | 63 |
| Twisting | |||
| Cotton | 78 | 25 | 57 |
| Man-Made | 73 | 23 | 57 |
| Warping | |||
| Cotton | 78 | 25 | 62 |
| Wool | 78 | 25 | 53 |
| Man-Made | 73 | 23 | 57 |
| Knitting Cotton | 76 | 24 | 63 |
| Weaving | |||
| Cotton | 78 | 25 | 77 |
| Wool | 78 | 25 | 55 |
| Man-Made | 73 | 23 | 65 |
| Tobacco | |||
| Cigar and Cigarette Making | 73 | 23 | 60 |
| Softening | 90 | 32 | 87 |
| Stemming and Stripping | 80 | 27 | 73 |
| Filler Tobacco Casing Conditioning | 75 | 24 | 75 |
| Filler Tobacco Storage and Preparation | 78 | 26 | 70 |