Munters DOAS and Chilled Beams Presented by: Scott McGinnis Regional Sales Manager LEED® Associate

Overview Chilled Beam Systems Moisture Control Munters Options Equipment

Whole Goal is to design a system where the Chilled Water temperatures throughout the building are consistent with the needs of the chilled beams and not driven by the OAU.

Active Chilled Beams

Neutral or Cold Air to Space Direct DOAS Design Advantages: Easier to measure the amount of outside air brought into the building (positive pressure). Easier to assure the outside air reaches the occupied zones. Dedicated ventilation diffusers allow easy airflow balancing (positive pressure). No outside air load is imposed on the terminal units. The space terminal units can be turned off when the space sensible load is satisfied.

Reasons For Chilled Beam Chilled Beams use ~57F Entering Water Temps

Reset Chilled Water up Energy Efficiency Manual

Reasons For Chilled Beam

Reasons For Chilled Beam

Calculating Building Moisture Load is More Important Size the DOAS to handle ALL the Internal Latent Load Prevents Chilled Beams from Sweating #1 Fear of Design Engineers I have spoken with Provides proper space %rh Delivered Sensible Temp to Beam effects the beams capacity

Calculating Building Moisture Load is More Important

Typical Buildings & DOAS Designs (does not handle the indoor humidity load) Space Served Dew Point Control Meeting Space Single 51-55 F Loose Grocery Store 48-52 F Medium Pharmaceutical 49-56 F Tight Hotel / Condo. Multiple 54–56 F Office 52-55 F Classrooms Healthcare Depends 42-52 F These outside air dew point design conditions do not take care of any of the indoor humidity loads. If the specialized outside air unit does not handle all or some of the space humidity load, then the space air conditions may still need to be improved to properly dehumidify the space.

How Dry Does the OA need to be? ASHRAE shows how to calculate how DRY the OA needs to be in order to control space moisture. If you want to maintain 75°F at 50%rh, then the space is at 55°F dewpoint. You need to deliver air dryer that 55°F dewpoint.

Use the Correct OA Condition 106 gr/# 131 gr/#

Internal People Load vs Ventilation QL = 1 person = 200 btu/per Ventilation Required 15 CFM per Person Capacity What dewpoint air at 15 cfm will absorb all the moisture given off by a person sitting at rest?

Math Ventilation Air: 15 cfm x 30 students = 450 (6,000 + 2,150*) btuh = 450 x .68 x Delta Grains 8,150 = 306 x Delta Grains 8,150 / 306 = 26.6gr/# Dewpoint of 450 cfm OA to achieve: 75°F/50% (55Fdp) = 42°F 75°F/55% (58F dp) = 45°F 75°F/60% (60F dp) = 49°F Lower than the past The Munters Story Munters Products *1600 btu/h = Simple Formula for Infiltration for standard classroom in 136 gr/# OA environment

Amount of OA? The greater the amount of OA, the higher the dew point can be The lower the amount of OA, the lower the lower the dewpoint If we mix RA with OA, then the same rules above apply

Conventional Options Coil Tonnage is large for Lower Dew Points

What to Offer with Chilled Beams Chilled Beams want 57-60F water in the coils DOAS needs low Dew Point air, thus needs low temp water Thus typically uses a coil with low chilled water temps; 42-45F EWT Is there an advantage of using just 57F water in the DOAS? 2x ? 42F to DOAS 60F to Chilled Beams Or one large chiller making 42F water and reheating that for the beams

ASHRAE Journal, Jan 2012

ASHRAE Journal, Jan 2012 Higher Space RH approach This approach is to use just a chilled water coil at standard coil conditions, maybe a little lower, i.e. 52F off the coil To make this work, recommends raising space min % rh in order to raise the space dew point. Saying higher %rh is space = no need for lower delivered dew points This seems to be as an attack on Desiccant, specifically Semco Pinnacle FW owns Semco and thus have a package they promote I personally feel trying to convince engr to raise the %rh floor will only help stifle the grown of chilled beams

This 45gr/# delivered system requires a Chilled Water Coil Delivering 52.7F Dry Bulb air: EWT = 45F Why use 45F water for this unit and 57F for chilled beams?

Chiller Efficiency Big Difference between 42F water and 60F water

Chiller Efficiency Big Difference between 42F water and 60F water 42F Chiller 32% Lower Op Cost 60F Chiller

Show the benefit of using High Temp water in the OAU and the Beams DryCool Process allows this DryCool Standard DryCool Plus 3 Fan dryCool ERV Custom DryCool All systems above use no chilled water or water with equal temperatures to chilled beam coil water Saves on chiller tonnage, and operating cost

120F OA/RA OA 74F @ 47 gr/# 62F @ 86 gr/#

HCUc: NO Chilled Water Air Water 46F DP 16 EER

Chilled Water DryCool: Higher Chilled Water 63F 57F 48F dp

How to Use DryCool With Energy Recovery? If Possible, use the DryCool ERV or 3 Fan DryCool No Need to Run Chilled Water to the DOAS Delete Pumps, Piping, Piping Insulation and such to unit. Down size Chiller plants for just the Chilled Beams and keep them at 60F water

Total Tons: CW (56) + DX (84) + Post (13) = 153 Tons 57F 82F/80Gr Dry Air 57F After E Wheel 69/44Gr 65F/80Gr 56F/61Gr Total Tons: CW (56) + DX (84) + Post (13) = 153 Tons Semco was at 156 Tons but required 45F Chilled Water

Semco 182”w x 146”h x 448” L

Enhanced Leaving Dew Point Control DryCool Standard and DryCool ERV Place a digital scroll compressor in the B position for modulating coil temp Set a discharge are dew point control Comp A is always on, but after that we can control pretty tight to DAT dew Chilled Water HCU By Modulating the Chilled Water coil we can control the leaving air Dew point Space control Monitor and control to the worse case space: Unit staging will fluctuate, may be some risk if dramatic moisture swings

Leaving Air Post Cool Coil Most cases the DryCool system will deliver supply air warmer than wanted Add a Chilled Water Post cool coil and set to leaving air conditions Use Chilled Beam water temps Munters can control

Passive DH depends on what is uncontrolled

Plan of Action for Chilled Beam Calc latent loads: Add those items not typically included People, Infiltration, Permeance DOAS equipment should take care of entire latent load How much OA will be bring be processing? DryCool Process: Drive the Moisture out of the DH Wheel KEEP CHILLED WATER TEMP UP! Benefits of one simple chiller plant with 58-60F water By using all package DX By using Hybrid of Chilled Water and DX with DryCool Use a standard product if possible Quicker selection Better price points Talk to factory about custom version to meet the engineers and owners needs Discharge air temps, control Layouts

Conclusion Chilled Beams do not need typical cold chiller water Use of DryCool Process can eliminate or raise chilled water temps Keeps chiller plant tonnage down Keeps chiller electrical use down Monitors and keeps Space moisture in check Small buildings (small section of buildings, additions, etc): DryCool Standard rio DryCool ERV Medium Buildings DryCool ERV or Custom HCU Larger Buildings Custom HCUs

Regional Sales Manager Questions??? Saving the planet, one LESS btu at a time Scott McGinnis Regional Sales Manager