Keeping Doc’s Cool, Dry & Happy “Can I Do The Job With What I’ve Got?” David N. Schurk DES., CEM., LEED-AP., CDSM., CWEP, SFP., CIAQM., HCCC. National Healthcare Strategic Accounts Manager Carrier Corporation

Connecting the Dots…How can we Help? Identify Problems Offer Solutions

170-2017 Narrative Notes: Source: ASHRAE

Source: ASHRAE

SPACE = 64°Fdbt @ 58% rh (49°Fdpt) Older OR’s = 350-400 sq ft. New General OR’s = 500-600 sq ft. Neuro/Ortho OR’s = 600-800 sq ft. Hybrid OR’s = 800-1200 sq ft. 15°F Outdoor ASHRAE HVAC Design Manual for Hospitals and Clinics Source: ASHRAE

“Typical internal cooling load is 2 to 3 tons “Typical internal cooling load is 2 to 3 tons. With an air change rate of 20 and supply air at 47°F to 50°F [8.3°C to 10.0°C], the system can provide 6 to 7 tons of cooling, roughly twice the actual load. Thus, in almost all operating rooms, the required ACH drives the size of the HVAC system, not the internal load”. Source: ASHRAE

REHEAT

“Although FGI and ASHRAE recommend a temperature range of 68°F to 75°F at 20% to 60% rh, many surgeons request temperature & humidity settings outside of these ranges. Inability to maintain low OR temperature is probably the number one complaint by surgeons to facility engineers”. Source: ASHRAE

“The Point of Diminishing “I Want it Colder!” Aka: I Want it Drier 60°f @ 40%rh “The Point of Diminishing Complaint” (DNS) Many times, lower RH values may be necessary in order to create an environment which can absorb perspiration and remove heat through multiple layers of clothing and into the surrounding dry air. Source: ASHRAE

70°F 65°F 60°F 53%RH 63%RH 75%RH 42°F CWT Space#1 Space #1 Space #1 At the same dew-point, as the space temperature goes down the relative humidity goes up. HUMIDITY TEMPERATURE 70°F 65°F 60°F 53%RH 63%RH 75%RH Too Warm Cool & Clammy Noncompliant Cold & Clammy Noncompliant 42°F CWT Space#1 Space #1 Space #1

70°F 65°F 60°F 37%RH 44%RH 53%RH Space#1 Space #1 Space #1 Too Warm At the same dew-point, as the space temperature goes up the relative humidity goes down. HUMIDITY TEMPERATURE 70°F 65°F 60°F 37%RH 44%RH 53%RH Too Warm Better Best Space#1 Space #1 Space #1

Traditional Mechanical Refrigeration Systems COOLED WARM B B Dry Bulb = Wet Bulb = Dew Point Air Leaves CC “Saturated”

70°F db @ 50% RH 60°F db @ 40% RH 51°Fdpt 48°Fdpt 41°Fcwt 36°Fdpt

Space °F DB Space RH% °F DP SAT °F DB CWT Reheat Chilled Water 70 50 50.5 47.5 40.5 17.5 Yes 40 44.6 41.6 34.6 23.4 Glycol 68 48.7 45.7 38.7 17.3 42.8 39.8 32.8 23.2 66 46.9 43.9 36.9 17.1 41.0 38.0 31.0 23.0 64 45.0 42.0 35.0 17.0 39.2 36.2 29.2 22.8 62 43.2 40.2 33.2 16.8 37.4 34.4 27.4 22.6 NA 60 41.3 38.3 31.3 16.7 35.6 32.6 25.6 22.4 Assumptions: Space latent load requires 3°fdpt depression, CWT to SAT approach is 7°fdb, SAT to space is 5°fdb ΔT. Note: Actual space load calculations are required to ensure performance, the above is only for approximation of temperatures.

Houston, TX 60°Fdb @ 40% rh = 35.64°Fdpt Supply Air = 32.64°Fdpt NOTE: If the operating room and it’s ventilation air is not properly dehumidified, anytime outdoor weather conditions are above the horizontal RED line moisture will be added to the space. 60°Fdb @ 40% rh = 35.64°Fdpt Supply Air = 32.64°Fdpt

Dallas, TX 60°Fdb @ 40% rh = 35.64°Fdpt Supply Air = 32.64°Fdpt NOTE: If the operating room and it’s ventilation air is not properly dehumidified, anytime outdoor weather conditions are above the horizontal RED line moisture will be added to the space. 60°Fdb @ 40% rh = 35.64°Fdpt Supply Air = 32.64°Fdpt

Show Them the Money! “Proper environmental control insures our hospital will maintain the surgical procedures that yield the most profit without fearing the loss of surgeons to competing facilities where OR conditions are more comfortable”. Source: Chief of Facility Engineering

Where Do I Go From Here?

33°F LCWT vs. 42°F LCWT < 12%-18% CAPACITY & EFFICIENCY Existing Chillers May be Incapable of Providing Colder Leaving Water Temperatures

Low-Temp & Glycol Chillers + Capable of lower DPT’s + Traditional refrigeration/HVAC + Understandable by most - Leaving air temps above freezing - Slightly complicates the system - May requires glycol - Lowers chiller efficiency - Reduces chiller capacity - Intensifies reheat Source: ASHRAE

Solid Desiccant System Schematic From Outdoors To Outdoors To Space To Be Dehumidified Post-Cooled Pre-Cooled

To Space To Outdoors Dehumidifies Humidifies May Eliminate Post Cooling May Eliminate Reheat Free Regen Heat (HRC) “Sterilizes” TD “Eloquent” To Be Dehumidified From Outdoors

“A desiccant technology that provides precise dehumidification, Humidification, and near sterilization of air flow provided to critical process/procedural areas”

* LD Dehumidifier OR Air-Handler OA Air-Handler Operating Room Regenerator OA Air-Handler Filter Cooling Fan Filter Htg Clg Fan OA Conditioner RA SA Humid Dehumid * Operating Room Heat-Recovery Chiller

“There is an ethical dimension to our failure to adopt technology, products, or protocols that improve the quality or duration of life - it is the moral equivalent of withholding life-saving medicine from a patient in need. The work of improving the delivery of healthcare is both urgent and necessary.” Sachin H. Jain MD, MBA President/CEO, CareMore Health System; Adjunct Professor, Stanford University School of Medicine. Thank-You