typical dry air application standards

Typical Application Standards

Application

Typical Conditions

Notes

Temp °F

Humidity

Aerosols

80

2 gr/lb dry air

Use hood over Freon charging nozzle and purge hood with very dry air

Brewing and Distilling Hops Storage Fermentation Rooms Filter Rooms Grain Storage

35 60

60%RH 45%RH 45%RH 40%RH

To reduce mold growth on walls To reduce mold growth on walls

Baking Sugar Storage Icing and Glazing Cookie Drying Filled Cookie Setting Potato Chips

80 80 65 20-30 75-80

35%RH 35%RH 20%RH 20%RH

Dry Air to minimize defrost requirement

Candy Caramel Cooling Bar Cooling Chocolate Hard Candy Making Hard Candy Packing Sugar Storage

60 0 90 75 75 80

40%RH 40%-50%RH 13%RH 35%RH 35%RH 35%RH

Care should be exercised in the systems design to insure against recirculating air-borne sugar dust in the system

Concentrates Molasses Grinding Honey Grinding Instant Coffee Packing Citrus Crystal Packing

80 80

Less than 25%RH Less than 25%RH 20%RH 15%RH

Do not recirculate – Pre-cool and dry to 20-25 gr/lb

Ferrous Cupola Dry Blast

40 gr/lb dry air

Crystal Growing

Varies

Dependent on particular salt

Crystal Cutting

Varies

Dependent on particular salt

Coils-Electronic

Lowest possible 1-3 gr/lb dry air

Prevent moisture absorption by insulation

Coils – TV and X-Ray

72

15%RH

Transformer Manufacturing and Rebuilding

80

5%RH

Elec. Appliances

72

15%

In blankets and pads with Nylon sheathing or insulation, moisture causes shorting and change in electrical characteristics and moisture absorbed in sealed sheath heating elements can cause failure and even explosion

Lightning Arrestor (Assembly)

60

20%RH

Typical Application Standards

Application

Typical Conditions

Notes

Temp °F

Humidity

Switch Gear Assembly

68

20-24%RH

Lamination

80

20%RH max

Paper, cloth or wood, glass fibers, etc. bonded with plastic, shellac, varnish or glue. Store material at 20%rh to insure good bond. Store finished goods at less than 80° F at 20%RH to prevent adhesion.

Chinchilla Raising

32-35

18-25%RH

High humidity is a health hazard. Low temperature and humidity provide denser and better pelts.

Matches

70

40%RH

For drying

Paper Coating

80

20%RH

For paper storage prior to coating with wax, plastic, adhesive, etc. To insure bond (See lamination) (Limit paper to 4% moisture)

Paint Spraying and Lacquering

80

50%RH or less

Control spray booth or cabinet to prevent blushing caused by moisture condensing on evaporative cooled surface (evaporation of paint or lacquer solvent) Do not recirculate.

Paper & Fiber Molding

80

20%RH

Finished-good storage to prevent sticky condition and loss of shape

Printing & Binding

90

30%RH

Paper storage to prevent excessive moisture content (4-6% maximum) and resultant high static electric charge. Changes in moisture content between impressions causes poor register.

Pharmaceuticals Ampoule Mfg. Penicillin Packaging Capsule Storage Colloids Cough Syrups Cough Drops Effervescent

80 80 75 70 80 70 90

30%RH 5-15%RH 35-40%RH 35%RH 40%RH 30%RH 15%RH

Hygroscopic Product Gelatin softens and distorts at higher temperature and humidity Similar to hard candy Powders or tablets

Extracts – Glandular Liver

70-80 70-80

5-10%RH 5-10%RH

Tablet Coating

80

5-30%RH

Tablet Compressing

70-80

10-30%RH

Powder Storage

70-80

15-30%RH

Powder Mfgr

70-80

15-30%RH

Powder Milling

80

35%RH

Plastics, Nylon, etc.

3-15%RH

35%RH

For drying and storage prior to molding

Plastics, Manufacturing Area for Thermo Setting and Moulding Compounds

80

25-30%RH

TV-Radio Broadcasting

70

20%RH

Tape head life extension

Typical Application Standards

Application

Typical Conditions

Notes

Temp °F

Humidity

Plastics, Laminated Built-up areas Parchment storage

70 70

20%RH 35%RH

High efficiency filters required to eliminate dust and fumes

Plywood

90

15-25%RH

Cold pressing

Rubber Products

Dipped Goods

75-90

25-30%RH

Dew point of air must be below evaporation temperature of solvent

Cementing

80

25-30%RH

Tire Cord

125

7%RH

For storage to prevent moisture absorption & resulting loss in adhesion with rubber

Glass Laminating

68-70

15-20%RH

To insure good long life bond

Explosives Gun Powder, Solid Fuels

35-75

10-50%RH

Range is great dependent on material, but storage is critical – e.g. – solid fuel power is calculated with consideration of time stored at given condition

Freezer Tunnel Vestibules

75

10-20%RH

Introduce air as curtain in front of tunnel opening

Pipe Galleries

40-80

40-50%RH

Maintain space dew point below piped fluid temperature to eliminate condensation. Maintain temperature to eliminate corrosion.

Telephone & Electrical Cable Wrapping

80

5 – 20%RH

Extra high voltage cable wrapping has no lower limit on moisture. Upper limit is about 5%RH.

Seed Drying & Storage

35-80

10-25%RH

Low temperature drying and low RH storage preserves germination potential

Food Drying Bins

95-105

2 gr/lb dry air

Spices – condiments

Transformer (Electric)

90

10-25%RH

Transistors

72-75

25-40%RH

Tubes – Radio

TV – Lighting

90

15-25%RH

Drying inside coating – There is no minimum moisture level – The dryer the air – the better

Missiles

35 80

35%RH 25%RH

Purging and cooling Assembly

Fertilizer Storage

AMB

40-50RH

Deliver air, 1-1/2 air changes/hour at 25%RH when corrected to ambient dry bulb.