ASHRAE Atlanta GA, USA EFRIARC Lisboa, Portugal Honorary Member SAIRAC Johannesburg, RSA AICARR Milano, Italia IIF/IIR Paris, France Listen > Design > Bid > Work in Progress > Ready-to-operate PRESSURIZATION : The key to controlling Air-Borne Virus and Microorganism migration. Walter D. Gameiro, PhD Mec. Eng. 1 Photos: Durango Hospital
Hospital Air Conditioning assumes a more important role than just comfort. These days proper AC is a factor in patient therapy. In some cases is the major treatment Controlled environment provide more rapid physical improvement than those patients with no air conditioning. Patients with Thyrotoxicosis do not tolerate Hot, Humid Conditions or Heat Waves. A Cool and Dry environment favors the loss of heat by radiation and skin evaporation and may save the life of a patient. Cardiac patients may be unable to maintain the circulation necessary to ensure normal heat loss. Walter D. Gameiro, PhD Mec. Eng. 2
AIR CONDITIONING CARDIAC WARDS and CARDIAC ROOMS, especially those with congestive heart failure, is necessary and considered therapeutic. AIR CONDITIONING for patients with HEAD INJURIES, subjected to BRAIN OPERATIONS and those with BARBITURATE POISONING may have HYPERTHERMIA, especially in a hot environment, due to a disturbance in the heat regulatory center of the brain. THEREFORE, an important factor in recovery is an environment in which the patient can loose heat by radiation and evaporation, and that means : a COOL ROOM with DEHUMIDIFIED AIR. Walter D. Gameiro, PhD Mec. Eng. 3
Rheumatoid Arthritis patients react better to treatment in an environment of 90 F and 35% Relative Humidity. Dry Conditions, in other cases, will be an hazard to the ill and debilitated by contributing to secondary infection or infection totally unrelated to the clinical condition that caused the hospitalization. Clinical Areas devoted to upper respiratory disease treatment and cute care, as well as general clinical areas of the entire Hospital should be maintained at a Relative Humidity of 30 60%. Chronic Pulmonary disease patients often have Respiratory Tract Secretions. As these secretions accumulate and increase in viscosity, the patient EXCHANGE of HEAT and WATER is REDUCED. Therefore, inspiration of WARM HUMIDIFIED air is essential to prevent DEHYDRATION. Walter D. Gameiro, PhD Mec. Eng. 4
Oxygen therapy Patients & those with Tracheotomies, require WARM HUMID inspired air. Cold and Dry Oxygen or the bypassing of the nasopharyngeal mucosa presents an extreme situation. Re-breathing techniques for Anesthesia and enclosure in an incubator are special means of addressing impaired HEAT LOSS in Therapeutic Environments. Burn patients need a HOT ENVIRONMENT and HIGH RELATIVE HUMIDITY. SEVERE BURN PATIENT WARD should have temperature controls allowing up to 90 F and 95% Relative Humidity.. Walter D. Gameiro, PhD Mec. Eng. 5
1. NEED TO RESTRICT AIR MOVEMENT IN AND BETWEEN THE VARIOUS DEPARMENTS. 2. SPECIFIC REQUIREMENTS FOR VENTILATION AND FILTRATION TO DILUTE AND REMOVE CONTAMINANTS SUCH AS ODOR, AIRBORNE MICROORGANISMS, VIRUSES, also HAZARDOUS CHEMICALS, AND RADIOACTIVE SUBSTANCES. 3. DIFFERENT TEMPERATURE AND HUMIDITY REQUIREMENTS FOR VARIOUS AREAS. 4. DESIGN SOPHISTICATION NEEDED TO PERMIT ACCURATE COMPUTER CONTROL OF ENVIRONMENT IN ALL THE DIFFERENT AREAS Walter D. Gameiro, PhD Mec. Eng. 6
WE DO NOT WANT CENTRAL DUCTED SYSTEMS. Infection Sources and Control Measures 1. Bacteria Infection examples that can be transported around by the AC duct system by air or air + water mixtures are: Mycobacterium Tuberculosis Legionella Pneumophila (In these cases our FILTRATION recommendation is 95% HEPA Filter at 1 m particles) 2. Viral Infection examples that can be transported around by the AC duct system: Varicella (chicken Pox / Shingles ). Rubella ( German Measles ) Rubeola ( Regular Measles ) Other Epidemiological sub-micron airborne size Viruses. (For these we have no known way to eliminate 100% of them including ultraviolet light or chemical sprays; Our RECOMMENDATION is Isolation Rooms and Ante- Rooms with the right Ventilation-Pressurization as THE PRIMARY PREVENTION TO SPREAD AIRBORNE VIRUSSES ) Walter D. Gameiro, PhD Mec. Eng. 7
3. Molds. Some molds such as Aspergillis can be fatal to advanced Leukemia, Bone Marrow transplant and other imunocompromised patients. 4. Outdoor Air Ventilation. When Outdoor Air Intakes are properly located in areas properly maintained around them, outdoor air in comparison with room air is virtually free of viruses and bacteria. Infection control problems are normally sourced inside the Hospital. Properly Designed, Constructed and Maintained Ventilation Air Systems dilute the viral and bacterial contamination within the hospital, preserving the correct pressure relations between the different functional areas and remove airborne infectious agents from the Hospital. 5. Temperature and Humidity These conditions can inhibit or promote the growth of bacteria and activate or deactivate viruses. Some bacteria such as Legionella Pneumophila are basically waterborne and survive more readily in a humid environment. Walter D. Gameiro, PhD Mec. Eng. 8
AIR QUALITY 1. OUTDOOR INTAKES. Locate as far as practical but at least 30 from combustion equipment stack exhaust, exhaust outlets, surgical vacuum outlets, cooling towers, plumbing stacks, smoke control outlets, as high as 12 off the roof. 2. EXHAUST OUTLETS. Locate on the roof away from door and air intakes. Blow exhaust horizontally and upwards. Take prevailing winds in consideration, not to contaminate the air intakes. 3. AIR FILTERS Proper selection and maintenance of all intake filters. Next slide will show filter criteria. Walter D. Gameiro, PhD Mec. Eng. 9
FILTER EFFICIENCIES in GENERAL HOSPITALS No. Filter Filter Efficiencies % Banks AREAS Pre Post 1 Post 2 ----------------------------------------------------------------------------------------------------------------------------------------------- Orthopedic Operating Room 3 Bone Marrow Transplant Op. Room 25 90 99.97 Organ Transplant operating Room ----------------------------------------------------------------------------------------------------------------------------------------------- General Procedure Room Delivery Rooms. Nurseries 2 Intensive Care Units 25 90 Patient Care Rooms. Treatment Rooms. Diagnostic and related areas ----------------------------------------------------------------------------------------------------------------------------------------------- 1 Laboratories. Sterile Storage 80 ----------------------------------------------------------------------------------------------------------------------------------------------- Food Preparation Areas. Laundries. 1 Administrative Areas. Bulk Storage. 25 Soiled holding Areas Walter D. Gameiro, PhD Mec. Eng. 10
AIR MOVEMENT and PRESSURIZATION 1. Maintain Highly Contaminated Areas at Lower Pressure than adjacent areas, to avoid spread bacterial to corridors and adjacent rooms. 2. This category areas are, Autopsy, Infectious Isolation Rooms. 3. Maintain Operating Areas at Higher Pressure, and the Ante-Room slightly negative, so both air from clean corridor & other operating rooms flows to the Ante-room where it is exhausted to the roof. 4. Maintain Protective Isolation Rooms at Positive Pressure. 5. Use Air-Locks or Ante-Rooms between critical rooms that require personnel moving between critical and adjacent spaces. 6. Critical Infectious Rooms, supply air diffusers or grilles above inlet door and exhaust low, 3 above floor, behind patient s bed. Visitors or nursing personnel will never be downstream from the source of contamination. Walter D. Gameiro, PhD Mec. Eng. 11
AIR MOVEMENT and PRESSURIZATION example : Room, Infectious Disease ( - ) Ante-Room ( + ) Corridor ( = ) Ante-Room ( + ) Room, Infectious Disease ( - ) Symbols : (-) Negative Pressure / (+) Positive Pressure / (=) Neutral Pressure. Door size > 4 X 6 7 X 8 Both Doors Condition > 30% open 60% open 100% 30% open 60% open 100% 30% open 60% open 100% Open Sq. Ft. > 7.2 14.4 24 16.8 33.6 56 24 48 80 Static Press. 0.0625 0.0625 0.0625 0.0625 0.0625 0.0625 0.0625 0.0625 0.0625 Q (CFM) = 4320 8640 14400 10080 20160 33600 14400 28800 48000 1/16" WC =0.0625 Walter D. Gameiro, PhD Mec. Eng. 12
SIMPLIFIED PROPOSED STRATEGY FOR THIS PROJECT 1. Surgery Rooms +, Critical Care +. Delivery +, Trauma +, Anesthesia =. Vertical Laminar Flow air Distribution, Positive Pressure, Exhaust Air directly Outdoors, 2. Nursing. Patient Room +, Intensive Care +, Protective Isolation +, Infectious Isolation -, Ante-Rooms -, Patient Corridor =. Reversible Heat Pump Recirculation Unit plus Outdoor Air, Exhaust through bathroom shaft. 3. Ancillary. Radiology (Surgery & Critical Care) +, (Surgery & Critical Care) =, Laboratories +, Autopsy -, Necrology =, Pharmacy +. Reversible Heat Pump Recirculation Unit plus Outdoor Air. 4. Administration +. Reversible Heat Pump Recirculation Unit plus Outdoor Air. 5. Diagnostic & Treatment. Bronchoscopy =, Exam Room +, Medication +, Treatment =, Physical Therapy -, Clean Workroom +. Reversible Heat Pump Recirculation Unit plus Outdoor Air. 6. Sterilizing & Supply. Equipment Sterilizing -, Decontamination Room -, Clean Workroom & Sterile storage +, Equipment Storage =. Reversible Heat Pump Recirculation Unit plus Outdoor Air. 7. Service. Food Preparation Center =, Warehousing =, Dietary Day Storage =, General Laundry -, Linen sorting & Storage -, Clean Linen Storage +, Linen & Trash Chute Room -, Bedpan Room -, Bathroom -, Janitor Closet -. Reversible Heat Pump Recirculation Unit plus Outdoor Air. Walter D. Gameiro, PhD Mec. Eng. 13
7 PRINCIPAL DIVISIONS OF AN HOSPITAL - Simplified Criteria 1. SURGERY & CRITICAL AREAS Operating Rooms (+) 62-80 F & 45 55% / Obstetrical Areas (+) / Delivery Rooms (+) Recovery Rooms (=) 75 F & 45 55% (keep anesthesia negative for odors), 75 F & 30 60% 2. NURSING Patient Room (+) 75 F, 30% Winter * 75 F, 50% Summer / Intensive Care (+) 75-80 F & 30-60% Protective Isolation Units (+) 75-80 F / Infectious Isolation Units (+) 75 F, 30% Winter * 75 F, 50% Summer / Floor Pantry ( = ) / Labor Delivery/ Recovery/Post Partum (+) 75 F, 30% Winter * 75 F, 50% Summer 3. ANCILLARY Radiology 75 80 F / Fluoroscopic, Radiographic, and Deep Therapy rooms 75 80 F & 40-- 50% / Laboratories (-) Comfort AC / Bacteriological Labs (-) low air velocities / Infectious Disease and Virus Labs (-) 6 air changes/hour min and sterilize exhaust at 600 F / Autopsy Rooms (-) Comfort (=) Charcoal Filters for odor. / Pharmacies (-) 4. ADMINISTRATION Main Lobby and Administrative Desk. Medical records. Business Offices. Waiting Rooms (areas of potential risk of transmission of undiagnosed airborne infectious diseases) (-) Never use a duct system in this area. Walter D. Gameiro, PhD Mec. Eng. 14
7 PRINCIPAL DIVISIONS OF AN HOSPITAL - Simplified Criteria 5. DIAGNOSTIC & TREATMENT Bronchoscopy, Sputum Collection, and Pentamidine Administration Areas, Unusual Ventilation high levels / MRI Magnetic Resonance, Just like exam rooms in Temp and Humidity but high sensible load to cool equipment / Treatment Rooms, Individual Temp & Humid. control at Patient Room levels. Physical Therapy Department, affected by Shortwave diathermry, infrared & Ultraviolet equipment. / Hydrotherapy Department, 80 F and treat like an indoor pool creating lots of latent heat (humidity), an odor control may be required. / Occupational Therapy, Normal recirculation w/ medium filters / Inhalation therapy, Pulmonary and other respiratory diseases; very clean air requirements and positive pressure. / Clean Workrooms, serving as storage and distribution centers for clean supplies, maintain positive pressure to the corridor. Soiled Workrooms, serve as collection points, so must be treated as contaminated rooms/ Walter D. Gameiro, PhD Mec. Eng. 15
7 PRINCIPAL DIVISIONS OF AN HOSPITAL - Simplified Criteria 6. STERILIZING & SUPPLY Cleaning Area, Sterilizing Area & Storage. If in common room keep air flowing from clean to contaminated. Temp as in comfort areas. Important guidelines:, 6.1- Insulate Sterilizers to reduce heat load. 6.2- Amply ventilation on sterilizing equipment to remove excess heat. 6.3- If Ethylene Oxide (ETO) gas sterilizers are used, use separate exhaust system with terminal fan. Proper velocity at ventilation hood at sources of ETO. Install an exhaust at sterilizer doors and above sterilizer drain. Exhaust Aerator and Service rooms as well. Install ETO sensors, exhaust fan flow sensors with alarms. ETO sterilizers should be located in dedicated unoccupied rooms and have highly negative pressure to adjacent rooms, min 10 ac/hour. OSHA requires ETO removal equipment from exhaust air. 6.4- All sterile supplies to be stored at 50% RH or lower. Walter D. Gameiro, PhD Mec. Eng. 16
Walter D. Gameiro, PhD Mec. Eng. 17 7 PRINCIPAL DIVISIONS OF AN HOSPITAL - Simplified Criteria 7. SERVICE Dietary facilities: Main Kitchen / Bakery / Dietitian Office, comfort AC / Dishwashing Room, Enclosed, High ventilation with hood exhaust may be divided in clean and contaminated area, then flow air from clean to contaminated / Dining Space, comfort AC with ASHRAE ventilation rates or local codes, overflow fresh air to Kitchen, using a 80% filter. If cafeteria type is used, employ hood above serving and steamed areas, min 75 cfm/sf of perimeter area. Provide special care to these areas characterized by high heat, high moisture production and cooking odors. Kitchen Condensing units. Remove absorbed power being thrown into the space. Maintain no more than 90 F Summer. Laundry Facilities. Contaminated areas, such as receiving linen, sorting, and contaminated utility have to be Negative Pressure and Odor treated exhausted directly outside. General Processing area, containing Washers, Flatwork Ironers, and Tumblers will have direct overhead exhaust to reduce humidity. Insulate equipment where possible to reduce high radiant effects. A hood over flatwork ironers. Feed air from leaving process area backwards to capture the heat in the process. Exhaust to the roof, in separate duct and equip with lint filters. We can do heat reclaim in this area. If AC is necessary insufflate outdoor air near the hood/canopy, kitchen style. Mechanical Facilities. Lots of fresh air to boiler room. Design to keep max 90 F at workstations. If outdoor air is above 97F pre-cool the air to protect the motors. Evaporative cooling may be employed Maintenance shops. Carpentry, machine, electrical, and plumbing workshops have no unusual requirements. Welding areas, require excellent ventilation. If we have paint workshop or storage exhaust to ventilate well and reduce fire hazard.
LOW ENERGY CONCEPTS ZONING : Use different systems for different departments. 1. Compensate for exposures due to orientation or other building conditions. Define Air intake zones and Air Exhaust zones & Separate them according to prevailing winds. 2. Minimize or make it zero recirculation between departments. So we don t move bacteria and viruses around by AC ducting. 3. Simplify provisions for operations on Emergency Generator Power. Pre-Select what really needs to be on and off, including pressurization of areas. 4. Conserve Energy. Use the required Btu/hour with the least KWh. This is a 24 Hour/day operation 365 days a year type of work. Walter D. Gameiro, PhD Mec. Eng. 18
Walter D. Gameiro, PhD Mec. Eng. 19 AIR CONDITIONING HOSPITAL REQUIREMENTS LOW ENERGY CONCEPTS 5. Goals : 5.1 - Move heat around from the side of the building that requires cooling (remove heat ) to side of the building that requires heating (supply heat ) using nothing but a two pipe system. If the budget is large enough, District Cooling Technology with a four pipe system. Employ Evaporative Cooling on Outdoor Air Supply every time the space to be served allows it. 5.2 - Employ Computer Control System for Air Conditioning and Ventilation & Pressurization Management, controlling Temperature, Humidity, Pressurization, Fans and Pumps Velocities with VFD Technology. 5.3 - Employ Air to Air Heat Recovery Technology between Exhaust and Outdoor Air Supply. 5.4 - Perform Heat Recovery from Solid Waste Incinerators to Pre-Heat Sanitary Water. 5.5 - Perform Heat Recovery from Boilers Effluent to pre-heat Sanitary Water. 5.6 - Recommend two level lighting.
LOW ENERGY CONCEPTS 6. Systems : 6.1 TRI-GENERATION / LNG Co-Generation + Chilled Water + Hot Water 6.2 DISTRICT COOLING if you have several buildings 6.3 CENTRALIZED HEAT PUMP 6.4 VIRUS & MICROORGANIM FLARE and ELIMINATION 6.5 ELECTRICALLY DRIVEN MECHANICAL CHILLERS. 6.6 LNG (or other fuel) DRIVEN MECHANICAL CHILLERS 6.7 HEAT RECOVERY for INEXPENSIVE WATER HEATING Walter D. Gameiro, PhD Mec. Eng. 20
HOW DOES PROPOSE TO WORK: Thermodynamics Air Conditioning, Heating, Ventilation, Heat Recovery Heat Pump Technology Software Development Choice of Hardware Development of Software Walter D. Gameiro, PhD Mec. Eng. 21
HOW DO WE WORK TOGETHER? Design the Energy Efficient Air Conditioning System according to best international practices and delivers a high quality product that is heath safe. Reduce Operational Costs and Maintenance. Maintain Tested State-of-the-Art Technologies Operational Simplicity: Easy to operate Easy to be understood Easy to troubleshoot by operators Walter D. Gameiro, PhD Mec. Eng. 22
HOW DO WE WORK TOGETHER? Phi Engineering will design all projects according to the latest European, USA and local codes. It is Phi Engineering responsibility to keep track of the latest modifications on national and federal regulations for building, mechanical, electrical and Hospital codes. Walter D. Gameiro, PhD Mec. Eng. 23
HOW DO WE WORK TOGETHER? HOSPITAL can rely on Phi Engineering for: State-of-the-art Energy efficient Engineering. State-of-the-art Ventilation Engineering. State-of-the-art Filtration and Pressurized Rooms. Permanent investigation for new technologies Great creativity supported by sound theory. All other common E/A disciplines in house as well. Walter D. Gameiro, PhD Mec. Eng. 24
HOW DO WE WORK TOGETHER? We can start design immediately. If we get immediate approval: Phi Engineering will require 2 to 3 weeks to design a Concept plan, subject to HOSPITAL revisions. Phi Engineering could issue for bidding 6-8 weeks, thereafter. Phi Engineering could issue for construction 10-12 weeks, thereafter. HOSPITAL could start Air Conditioning job, 15 weeks after project awarding is completed, subject to eventual permitting delays, if any. Walter D. Gameiro, PhD Mec. Eng. 25
HOW DO WE WORK TOGETHER? ASHRAE Atlanta GA, USA EFRIARC Lisboa, Portugal Honorary Member SAIRAC Johannesburg, RSA AICARR Milano, Italia IIF/IIR Paris, France Phi Engineering After doing the first meeting with HOSPITAL s technical staff, to define objectives. After we agree in just about all details. We would eventually have made some recommendations to current layout that would still improve sanitary and safety conditions. Phi Engineering Design & Consulting Corp. Can we help and serve you better? Walter D. Gameiro, PhD Mec. Eng. 26