1. Regional Manager for Munters
Lennart Bosman
Benefits of Humidity Control in Low Temp Spaces
38 years in the industry primarily with the food, pharmaceutical and archival markets to reduce and control humidity within production and storage facilities. Provides engineering and sales support to solve problems or implement strategies to improve or streamline facility operations.
Regional Manager for Munters
Placeholder SLIDE
Dealing primarily with the food, pharmaceutical and archival markets to reduce and control humidity within production and storage facilities

2. Lets start by defining low temperature spaces, separating them into three zones: Cool ~ 60 F and up (30 to 60%RH, 29 to 46 dew point) Labs, operating rooms, surgical suites Cold ~ 33 F to 59 F Storage, loading docks, processing rooms Frozen – below 32 F Long term storage

3. Cool, Cold or frozen rooms?
Cool/Cold rooms
Loading docks
Meat processing rooms
Meal assembly rooms
Laboratories
Lasik and other surgery suites
In all the above if the dew point delivered is above 40 F, the use of refrigeration is most likely the best solution.
Frozen rooms, below 32F…
Process Freezers
Hardening tunnels
Cold storage
In all frozen rooms or if the dew point desired is below 40F, you should use desiccant.

4. Psychrometric-terms... Refrigeration viability only above the line
Grains/lb
Refrigeration viability only above the line

5. Methods of dehumidification...
Cooling based (condensing)
DX refrigeration, sub-cool and reheat
Chilled brine
Ammonia
Co2
Desiccant based (adsorbtion)
Stacked tower
Liquid spray systems
Wheel systems

6. In either case, cold rooms or frozen rooms, first, determine the load...
The humidity loads are;
Permeation
Infiltration
Internally created
Then size the dehumidifier to match the project needs and loads

8. Munters company presentation
Design conditions
May 4, 2019
Munters company presentation

9. Munters company presentation
Permeation
May 4, 2019
Munters company presentation

10. Munters company presentation
People load
May 4, 2019
Munters company presentation

11. Munters company presentation
Pass through
May 4, 2019
Munters company presentation

12. Munters company presentation
Air lock or vestibule
May 4, 2019
Munters company presentation

13. Munters company presentation
Cracks
May 4, 2019
Munters company presentation

14. Munters company presentation
Total Internal load
May 4, 2019
Munters company presentation

15. So, how much dryer do we need?
This is the difference between what we want in the space and what the dryer can supply
May 4, 2019
Munters company presentation

16. For cool rooms we would use Cooling-Based Dehumidification

17. Reducing humidity or Eliminating Ice
To reduce or eliminate ice accumulation the moisture level (dew point) must be low enough to prevent condensation on cold surfaces, so dehumidification is required.
To understand the limitations of condensation control in low temperature spaces one must first recognize the differences between the two methods of dehumidification – cooling versus desiccant.
Both technologies remove moisture from air. The primary difference is the dew point of the air that each can effectively deliver.

18. Psychrometrics of Cooling-Based Dehumidification
Air is circulated over a cold coil and cooled to saturation
Further cooling condenses moisture on coil fins
Dew point reduction is limited by minimum practical coil temperatures (freezing)
Subfreezing areas that utilize this method must deal with ice build-up on evaporators, walls, floors, ceilings, door frames, etc.
Regularly scheduled defrosts are needed and have become the standard operating procedure.
NOTE: Primary objective is temperature control, dehumidification is a byproduct.

19. Typical Cooling Coil Performance
Cold Air Discharge From Coil At 50°fdb, 95% Relative Humidity
51 gr./lb. = 49oF dewpoint
Humid Air Entering Coil At 75°f, 70% Relative Humidity
92 gr./lb. = 65oF dewpoint
Cooling Coil (CW or DX)
Moisture Condensed Out By Lowering Air Temperature
(92-51 = 41 gr./lb. in this example)

20. Typical Coil Performance Below Freezing
FROST AND ICE BUILD UP ON COIL CAUSED FROM SURFACE TEMPERATURES BELOW 32°F
FROST
FOG
HUMID AIR ENTERING COIL AT 40°FDB, 70% RELATIVE HUMIDITY
COLD AIR DISCHARGE FROM COIL AT 25°FDB, 95% RELATIVE HUMIDITY
MOISTURE CONDENSING LIMITED BY COIL TEMPERATURE FREEZING 32°FDB

21. Psychrometric Plot Typical Cold Storage
PSYCHROMETRIC PLOT OF CONDITIONS IN PROCESS FREEZER & COLD STORAGE APPLICATIONS WITHOUT DESICCANT DH 40
140 35
120 30
PACKAGING AREA
AT F
100
Enthalpy - Btu per Pound of Dry Air 25 80
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb) 20
Fog 60 15
Frost 40
Ice 10 20
-10
-10 10 20 30 40 50 60 70 80 90
100
110
Dry Bulb Temperature °F

22. Desiccant-Based Dehumidification

23. Psychrometric Plot Cold Storage with desiccant DH
PSYCHROMETRIC PLOT OF DESIGN CONDITIONS IN PROCESS FREEZER & COLD STORAGE APPLICATIONS WITH DESICCANT DH 40
140 35
120 30
100
Enthalpy - Btu per Pound of Dry Air 25 80 20
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb)
Humidity Ratio Grains of Moisture per Pound of Dry Air (gr/lb) 60 15 40 10 20
-10
-10 10 20 30 40 50 60 70 80 90
100
110
Dry Bulb Temperature °F
DEHUMIDIFY TO 5.5 GR/LB
( -20 F DEW POINT)

24. Desiccant Dehumidification:
Wheel carries desiccant
Desiccant wheel removes moisture from process air
Wheel rotates to reactivation section. Heated air drives moisture away
Supply (dry) air has dew point below surface temperatures
Dry air acts as a sponge, preventing moisture from condensing on surfaces.
Defrost cycles extended considerably, evaporators operate efficiently.
NOTE: Primary objective is dehumidification

25. Working in cold storage… is not always easy

26. Applications in cold environments…
Loading docks - large infiltration loads from truck doors
Cold storage freezers - moisture from loading dock and process area
Spiral freezers – moisture from product and the environment
Plate freezers – moisture from environment
Process freezers – moisture from product and environment
Meat processing - moisture from various sources causing overhead condensation

27. Control the Dew Point
Reduce temperature - moisture will condense on machinery, walls or product.
Relative Humidity (RH) compares how much moisture is in the air and how much it can hold
100% RH is saturated air
Over 60% RH results in condensation and then mould growth
Dehumidification prevents condensation and reduces mould growth

28. Effects of Door Openings on Freezer
Fog and condensation
Ice on Floors, Walls, Doors & Evaporators
Extensive cleaning time
Food warms (food quality / safety)
Refrigeration plant over worked
Increased energy consumption
Increased defrosts (inefficient, increased downtime)
Ice in room (worker safety, reduced operator speed)
Contamination through door
Iced evaporator (reduced air flow, increased maintenance)

29. The warehouse culprit..
Many cold stores are not equipped with an airlock, often using plastic strip curtains to reduce the amount of moisture introduced when the door is opened.
This approach does not provide a complete vapor barrier. Moisture still infiltrates into the cold store, ice builds up on evaporators, overhead structures, door mechanisms, floor, etc.

30. Freezer Air Lock / Loading Dock
In addition to Ice, fog & frost this causes:
Blinding strip curtains
Poor visibility
Lost cooling capacity
Extended loading times
Fork truck and structural damage
High maintenance cost of doors etc.
Need for mechanical de-icing

31. risk of accidents caused by slippery floors
Problem: SAFETY
Unsafe environment -
risk of accidents caused by slippery floors
Can be very costly $$$

32. In some cases the problem has to be attacked from inside the freezer, there are units on the market that can do this, delivering -40 to -57 F dew point

33. Limited Access Cold Storage
Stand alone unit designed to run continuously, providing ice removal 24 hours per day.
Cost effective solution for limited access areas:
cold storage doors open < 10 minute per hour
facility doesn’t operate 24 hours per day. Gives IceDry® chance to remove moisture that infiltrated during the day.
If door activity varies or is expected to increase in future then include an air curtain in design to improve dry air distribution over the cold door.

34. Stand-Alone Solution

35. Combining desiccant with an Air Curtain can be the best response
Cold Store -20°F
Dry Air
Dew -55°F
Munters
IceDry

36. KLM Catering Services
Before
After

37. Freezer / Loading Dock One example LOADING DOCK FREEZER LOADING DOCK
Frost & Ice build up
TEMP = -13oF (25oC)
TEMP + 41oF (5oC)
85% RH
32 gr./lb (4.5 g/kg.)
Warm air
inflow
Moisture
leakage
Fog
Cold air
outflow
Wet floor
Iced floor

38. With Dehumidifier Installed
Desiccant dehumidifier keeps the Loading Dock dry,
reducing the moisture load to the Freezer
Moist air from
Loading Dock
Dehumidifier
Dry air
Frost free
Cold Storage Area
Moisture
infiltration
Dry floors
Dry floors

39. Dehumidification & Defrosts
Defrosting is an expensive business
One open door (8’ x 10’) can allow 1 gallon of water to enter a cold Freezer every minute
When ice settles on a cooler, the refrigeration system has to cool through a layer of insulating ice
Defrosts can represent 15% of energy consumption in Freezers

40. Benefits of Dehumidification
Floors/doors kept dry and ice-free
Speed up loading and unloading
Fork trucks operate at normal speed
Reduced occupational injuries from slips, falls and pallet mover accidents
No ice on strip curtains or fog around door, visibility is improved
Trouble-free pulldown after washdown
Coils run more efficiently and run longer between defrosts
One customer saved $20K in 8 mos.

41. Frost and Ice removal Advantages
Reduced Labor Costs:
No more chipping away ice by hand.
Improved Worker Safety:
Reduction of slippery floors and no ice falling from overhead surfaces.
Reduce costly worker injuries
Elimination of fog improves visibility.
Increased Productivity:
Loading time is reduced when fork truck operators can move efficiently across ice-free floors and their visibility is high.
Lower Maintenance Costs:
Reduced electrical and mechanical failures = less downtime.
Switches, motors, lights, and evaporators (fins, tubes) do not suffer from ice build-up.
Fewer floor repairs due to heaving and cracks.
Before
After

42. Before After

43. Evaporators Before & After

45. 15 days later

46. Roof Void Condensation
Fire detection impeded
Moisture leaching through into insulation - freezes
Smallest perforations can penetrate and increase weight
Lose insulation value
Reduced safe working load for panels
Panels bowing and collapsing

47. Dehumidification for Process Freezing

48. Frozen Baguettes Moisture Sources: Product releases moisture
Infiltration of moist production air
Washdown water
Benefits of Dehumidification:
Increase production capacity
Less stoppages due to defrosts and cleaning
Constant product quality
Reduced cleaning labor
Reduced high investments to increase freezer capacity
Fast payback
Energy savings through quicker cooling after washdown

49. In process freezer dehumidification increases operation between defrost cycles

50. Ice Cream Plant
Problem: Electronic Sensors In Carousel Freezer Coating With Ice Requires Manual Cleaning Every Two Hours
Freezer Maintained at -35°F
Solution: Dehumidify Ante-Room Surrounding The Carousel Freezer With Dry Air
Force All Air Being Drawn Into The Freezer To Be Dehumidified.

51. Ice Cream Plant
Before Installation of Dehumidifier

52. Ice Cream Plant
After Installation of Dehumidifier

53. Summary
Desiccant dehumidification reduces or eliminates moisture problem in PRW’s and food processing areas
Evaluate benefits of controlling 3 phases of moisture:
Vapor – fog, mist. Eliminating fog will improve visibility, increase worker safety, and raise productivity.
Liquid – water, condensation. Eliminating condensation will maintain dry floors (improve worker safety and productivity), dry packaging materials (enhance product quality and shelf life), and prevent product adulteration (improve food safety and reduce scrap). Dry coils will also pay efficiency dividends.
Solid – ice. Reducing / eliminating ice will extend time between defrost cycles (saving energy and increasing productivity), reduce maintenance costs, and improve worker safety.

54. Questions?
Any questions?
Thank you!