Download presentation
Presentation is loading. Please wait.
1
Cheryl Hughes Regional Sales Manager October 6, 2015
Munters Heat Exchangers Brad Perdew Applications Engineer 8/27/12 DOAS Configurations Cheryl Hughes Regional Sales Manager October 6, 2015
2
Munters DOAS Configurations Presentation
Purpose of Dedicated Outside Air Systems Review Building Loads Talking Dew Point is Critical How DOAS is Applied Munters Core Components Munters DOAS Configurations Munters Cost to Operate Spreadsheet
3
Purpose of DOAS ASHRAE recommends decoupling sensible and latent loads
ASHRAE recommends lower delivered dew points Lower than the original “Neutral Air Unit” Lower than standard packaged DX or chilled water can deliver Outside air is good, but consumes a lot of energy to treat 90.1 wants to reduce energy LEED makes you prove you have reduced energy
4
Sensible Loads Have Reduced – Less Cooling Required, Less “Reheat” Available
= Reduced Lighting Load = Reduced Solar Load = Improved Envelope
5
No Reduction in Moisture Load – Requires Active Dehumidification
Outdoor Air People Infiltration Operations
6
Typical Buildings – Design Dew Points
Space Served Dew Point Control Meeting Space Single 51-55°F Loose Grocery Store 48-52°F Medium Pharmaceuticals 49-56°F Tight Hotel/Condo Multiple 54-56°F Office 52-55°F Classrooms Healthcare Depends 42-52°F
7
Supply Air at the Correct Dew Point
Chart accounts for internal latent load of occupants at 200 Btu/hr/person
8
& TOTAL ENERGY RECOVERY
Multiple DOAS Options Different DOAS technologies Different system combos and methods of laying out DOAS Standard or custom solutions for every application Best EVAPORATIVE COOLING SENSIBLE ENERGY RECOVERY DEHUMIDIFICATION & TOTAL ENERGY RECOVERY EVAPORATIVE COOLING & SENSIBLE ENERGY RECOVERY
9
Munters Products Core Components
Focus on Humidity Control Over-Cool & Reheat Wringer Cycle Cooling Coil Surrounded by Single Heat Exchanger Active Desiccant Reactivated by external source of heat Reactivated using “site recovered” energy Focus on Energy Recovery Wheels – Enthalpy or Sensible Heat pipes Plates – Counter-flow or Crossflow EPX – Polymer Tubes
10
Munters DOAS Products Without Exhaust Air Energy Recovery
Cool-Reheat Wringer DryCool / HCU DDS (Config 1,2 & 5) HCD ICA With Exhaust Air Energy Recovery Sensible Heat Recovery Total Heat Recovery Sensible Wringer Plus Total Wringer Plus DryCoolERV DDS (Config 3 & 4)
11
Old Version of “Neutral” air to space
75°F at 55°F dewpoint = 50% rh 55°F 75°F DX Cooling Coil Hot Gas Reheat Compressors Supply Fan OA S/A
12
Now DOAS Should Deliver “Over Dried” Air to Space
75°F at 45°F dewpoint = 35% rh 45°F 75°F DX Cooling Coil Hot Gas Reheat Compressors Supply Fan OA S/A
13
Cool-Reheat (Brute Force)
Cool air to desired leaving dew point and then reheat it to “Space Neutral” temperature Reheat must not be a "new" energy source per 90.1 Packaged DX unit (with Hot Gas Reheat) Highly competitive, Munters rarely sells Outside Air SA Cool Reheat
14
Over-Cool & Reheat (Common Selection)
60 ton CU 47.5F dp
15
Wringer Introduced by Des Champs in 1980 as a patented process surrounding a dehumidification coil with a single energy recovery device First pass across energy recovery device pre-cools humid air before coil Reducing refrigeration requirements Second pass across energy recovery device reheats leaving air, reducing or eliminating the need for supplemental reheat Achievable dew point limited by coil temperature SA Sensible Heat Exchanger Outside Air Cool Reheat Rule of Thumb is 25% cooling load reduction.
16
Wringer 50 ton CU 46.4F dp Rule of Thumb is 25% cooling load reduction.
17
Exhaust Air Energy Recovery
Pre-conditions OA with energy recovery device before cooling to desired dew point and then reheat it to space neutral temperature Energy Recovery Device SA EA CW Coil DX (AC/WC/WSHP) Reheat Outside Air Return/Exhaust Air Rule of thumb is 50% Summer tonnage reduction and 50% winter heat reduction.
18
Special WARNING About Energy Recovery System Performance!
Critical Relationship
19
Exhaust Air Energy Recovery
50 ton CU 46.5F dp Rule of thumb is 50% Summer tonnage reduction and 50% winter heat reduction.
20
Wringer Plus Adds exhaust air energy recovery, sensible or total, to a Wringer SA EA Cool Enthalpy Wheel Heat Pipe, Plate or EPX Sensible Wheel Heat Pipe or Plate Reheat Outside Air Return/Exhaust Air Up to 65% summer tonnage reduction and 55% winter heating reduction.
21
Wringer Plus 30 ton CU 46.2F dp Up to 65% summer tonnage reduction and 55% winter heating reduction.
22
DryCool – Hybrid Cooling plus Active Desiccant DH
Outside air first passes the pre-cool coil to < 60F saturated The pre-cooled air then passes thru the desiccant wheel to continue drying the air to ~45Fdp, the dehumidification process simultaneously raises the dry bulb temperature to ~75F Combining pre-cooling with active desiccant dehumidification reduces refrigeration requirements by ~40% Outside air for reactivation is heated by a condenser coil, the rest of the condenser heat is rejected to atmosphere Desicccant DH Wheel SA EA Cool Outside Air Outside Air Uo to 40% below the DX/Cond reheat option. Go to this when you want to be better than 90.1 baseline
23
DryCool Standard / HCU 40 tons precooling 43.6F dp
25
DryCool Chilled Water One 10 ton DX ckt 45.3F dp
26
DryCool ERV Adds exhaust air energy recovery to DryCool unit
Suitable for indoor installations Desicccant DH Wheel Cool Outside Air Return/ Exhaust Air React Condenser Coil A Condenser Coil B Energy Recovery Wheel Outside Air
27
DryCool ERV 26 ton CU 43.7F dp
28
Enthalpy Wheel + Desiccant
29
Cost to Operate Comparison
30
Munters DOAS Presentation Recap
Dedicated Outside Air Systems should be considered for all occupied spaces to provide adequate ventilation and meet codes Properly conditioning outside air takes a lot of energy, it makes sense to consider all ways to reduce operating costs Sizing and operating DOAS to maintain proper humidity control is crucial to occupant comfort and integrity of the building envelope Munters experience in humidity control plus Des Champs experience in energy recovery provide customers with a wide range of product options and expertise Each Munters system design has advantages and limitations to consider and can be compared side by side to aid in the decision making process
31
Questions
Similar presentations
