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5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

MODULE 5 HVAC FUNDAMENTALS OF MODERN DESIGN

Module 5 PG1 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

MODULE 5 GOAL Provide a fundamental understanding of Laboratory Heating, Ventilating and Concepts and Systems

Module 5 PG2 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 6 Outline

• Issues • Drivers • Concepts • Systems

Module 5 PG3 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Issues • “It’s too hot and humid in my lab!” Some of the most common concerns of • “It’s too cold and dry in laboratory facility users are relative to the my lab!” HVAC system, including: • “It’s like a tornado in my lab!”

Module 5 PG4 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers

• Laboratory Equipment Heat Generation • Air Change Rates • Containment Equipment • Occupant Gowning Requirements • Type of Laboratory and Science

Module 5 PG5 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Laboratory Equipment Heat Generation

Heat Generation Information • Heat is expressed in BTU/Hour • 1 Watt = 3.414 BTU/Hour • : Energy Required to Change Temperature • : Energy Required to Remove Moisture • One Ton of Air Conditioning: 12,000 BTU/Hour or 3,515 Watts • 135 cfm of outside air equals 1 ton of cooling (Kansas City weather) Module 5 PG6 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Laboratory Equipment Heat Generation

Loads for Bench Mounted Equipment (low density)

Item Bench L.F. Btuh Optical 2 222 2 24 Computer & Monitor 4 461 Rotary 3 253 Total 11 960 Btuh Per Linear Foot 87 Watts per linear foot 26

Sources: ASHRAE 2001 Fundamentals Handbook Labconco Catalog Revco Freezer Data Sheets NOTE: This is heat release, not equipment nameplate electrical data

Module 5 PG7 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Laboratory Equipment Heat Generation

Loads for Bench Mounted Equipment (high density)

Item Bench L.F. Btuh Optical Microscope 2 222 Small Centrifuge 3 304 Thermal Cycler 2 795 Fluorescent Microscope 2 700 Flame Photometer 2 365 Rotary Evaporator 3 253 Total 14 2639 Btuh Per Linear Foot 189 Watts per linear foot 55 Sources: ASHRAE 2001 Fundamentals Handbook Labconco Catalog Revco Freezer Data Sheets

Module 5 PG8 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Laboratory Equipment Heat Generation

Loads for Floor Mounted Equipment (high density)

Item Floor L.F. Btuh Ultra Low Freezer 4 3618 Large Centrifuge 4 4014 Large 4 4556 3 1672 Total 15 13860 Btuh Per Linear Foot 924 Watts per linear foot 271

Sources: ASHRAE 2001 Fundamentals Handbook Labconco Catalog Revco Freezer Data Sheets

Module 5 PG9 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Laboratory Equipment Heat Generation Two Module Lab Example (484 SF): • 16 feet of space allocated for floor mounted equipment • 48 feet of bench space • Assume half the bench is full – 24’ of equipment Heat Generated using moderate density: • Bench: 138 btuh/ft X 24’ = 3312 btuh • Floor: 662 btuh/ft X 16’ = 10,592 btuh • Total: *13,904 btuh More than 1 ton of A/C • Using 100% outside air in Kansas City: 57,300 btuh (4.75 tons) *There is no diversity in this number Module 5 PG10

5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Laboratory Equipment Heat Generation When figuring equipment heat gain: • Use published or measured heat release information, not electrical nameplate • Apply diversity carefully based on expected lab use • Consider sub-metering loads in similar buildings prior to planning a new lab • The answer is not “10 watts/sq.ft.”

Module 5 PG11 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Air Change Rates • 1 Air Change per Hour – The Amount of Air in Cubic Feet per Minute (CFM) it Takes to Completely Replace the Air in a Laboratory once in One Hour • CFM = (Floor Area x Ceiling Height x Air Change Rate)/60 • 135 CFM per One Ton of Cooling • Standards and Guidelines Vary from 4 to 12 AC/hr

Module 5 PG12 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Air Change Rates • 2 Module Laboratory (22’ x 22’); 484 SF • CFM Requirement for varying ceiling heights and air change rates

MORE IS NOT NECESSARILY BETTER Airflow in CFM at Given Air Change Rate

Ceiling Height 6 8 10 12 9 436 581 726 871 10 484 645 807 968 11 532 710 887 1065 12 581 774 968 1162

Module 5 PG13 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Air Change VS. Fume Hoods

• 2 Module Laboratory (22’ x 22’); 484 SF

• CFM Requirement for varying ceiling Nominal CFM heights and air changes

5' Fume 6' Fume 8' Fume Hood Hood Hood Airflow in CFM at Given Air Change Rate 960* 1180* 1660* Ceiling Height 6 8 10 12 610** 750** 1060** 9 436 581 726 871 * Sash full open; face 10 484 645 807 968 11 532 710 887 1065 velocity 100 fpm 12 581 774 968 1162 ** Sash at 18”; face velocity 100 fpm

Module 5 PG14 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Containment Equipment Approximate Exhaust CFM for 6’ BSC • Class II Type A2 Cabinet without canopy: 0 cfm • Class II Type A2 Cabinet with canopy: 600 - 700 cfm • Class II Type B2 Cabinet : 1150 cfm (requires a dedicated exhaust

Select the correct cabinet for the application

Cabinets that use ECM motors have significantly lower heat gain and

higher efficiency than PSC motors Module 5 PG15 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Air Changes VS. Containment Equipment

• * often use 4 to 6 times more energy per sq. ft. than a typical office building • *Nearly half of electrical energy used in a laboratory building can be attributed to ventilation • The decision on air exchange rates and fume hood sash position affect both first cost and lifetime building energy Annual electricity use in Louis Stokes Laboratory, National Institutes of Health, Bethesda, MD costs Courtesy of Labs 21

*Courtesy of Labs 21

Module 5 PG16 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Gowning/PPE

Impact of Gowning/PPE in Laboratory • May require reduction in Laboratory Design Temperature • Reducing Design Temperature from 72 deg. F to 70 deg. F results in: • A 12% increase in cooling airflow • A 12% increase in cooling capacity

Module 5 PG17 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Type of Laboratory/Type of Science

Animal Holding Rooms • 10 to 15

Module 5 PG18 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Type of Laboratory/Type of Science

Instrument/Computational Laboratories • High Equipment Heat Loads

Module 5 PG19 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Drivers – Type of Laboratory/Type of Science

Chemistry/Analytical Laboratories • High Fume Hood Density

Module 5 PG20 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

MODULE 5 – BASIC CONCEPTS

Laboratory Hazards Containment Flexibility & Redundancy

Module 5 PG21 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Laboratory Hazards

Health Hazards • Irritants • Corrosive Substances • Allergens • Asphyxiants • Carcinogens • Reproductive Toxins • Neurotoxins Flammability Hazards Reactivity Hazards Explosive Hazards Biohazards Radioactive Hazards Module 5 PG22 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Containment Primary Containment • First Level of Containment; typically a containment device: chemical fume hood, biological safety cabinet, etc.

Module 5 PG23 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Containment Secondary Containment • Second Level of Containment: • Laboratory Envelope • Directional Airflow • 100% Outside Air • Differential Pressure or Volumetric Offset • Doors must be kept closed • Exhaust fans run continuously

Best Practices: Use Primary and Secondary Containment to Protect Personnel from Exposure to Hazards

ANSI Z9.5 requires air movement from lower hazard to higher hazard Module 5 PG24

5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Containment

Primary Containment Devices - Chemical Fume Hoods • Bench Mounted Chemical Fume Hoods • Each Fume Hood uses as much energy as an entire house*

* From Labs 21

Module 5 PG25 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Containment Primary Containment Devices - Chemical Fume Hoods • Floor Mounted Chemical Fume Hoods or Ventilated Enclosures

Module 5 PG26 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Primary Containment Devices - Chemical Fume Hoods • Floor Mounted Hood Location is Critical

Module 5 PG27 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Containment

Primary Containment Devices - Chemical Fume Hoods • Radioisotope Hood • interior • Requires dedicated exhaust fan • Coved corners for decontamination • May need HEPA filters • Consult your Radiation Safety Officer

Module 5 PG28 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Containment

Primary Containment Devices - Chemical Fume Hoods • Perchloric Acid Hood • Acid resistant interior • Dedicated acid resistant ran • Acid resistant sealed ductwork • Washdown system • Treat wastewater from washdown • Do NOT manifold these hoods

Module 5 PG29 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Containment

Primary Containment Devices - Chemical Fume Hoods • Variable Volume Fume Hood • Face velocity is maintained constant as sash is raised and lowered • Requires pressure independent control device • Requires variable control – usually exhaust air bypass • Must maintain a minimum flow when sash is fully closed (ANSI Z9.5 no longer specifies how much) Module 5 PG30 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Containment

Primary Containment Devices - Chemical Fume Hoods • “High Performance” Fume Hood • Hood provides containment at lower face velocity • Each manufacturer uses a different design • Apply with caution Labconco • “Low Flow does not necessarily equate to “High Performance” • More sensitive to cross drafts

Lawrence Berkeley Labs Module 5 PG31 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Containment

Primary Containment Devices - Chemical Fume Hoods • “Ductless” Fume Hood • Uses and/or HEPA filters • Use only in tightly controlled conditions • NFPA 45 allows only for nuisance vapors & dusts

Module 5 PG32 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Containment

Primary Containment Devices – Biological Safety Cabinets • Personnel protection • Environmental protection • Can provide product protection • Not a chemical fume hood!!!! • Used for biological/microbiological work

Module 5 PG33 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Containment Biological Safety Cabinets (BSC’s) • Class I: Ventilated cabinet for personnel and environmental protection. No product protection • Class II: Ventilated cabinet for personnel, product, and environmental protection. Type A1, A2, B1, and B2 • Class III: Totally enclosed ventilated cabinet of leak-tight construction. Operations conducted through attached rubber gloves. Sometimes called glove boxes.

Select the correct cabinet for the application Module 5 PG34

5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Other Devices (Non Containment)

Other Devices – Not Chemical Fume Hoods • Canopy Hoods • Snorkels • Slot Hoods

Module 5 PG35 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Other Devices (Non Containment)

Other Devices – Canopy Hoods • Not appropriate for fumes • Hot applications only (ovens, GC/MS, non-hazardous hot tanks, glassware washing, cage washing, etc.) • Must have mass of hot moving air to contain

Module 5 PG36 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Other Devices (Non Containment)

Other Devices – Snorkel Hoods • Bench top activities that require exhaust • Ideal containment device for dissections • Good for bench top soldering, etc.

Module 5 PG37 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Flexibility and Redundancy

Three truths for the Laboratory HVAC Designer • What’s happening in the laboratory tomorrow will be different than what’s happening today • Fume hood density nearly always increases over time • The amount of heat generating equipment will increase over time

Module 5 PG38 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Concepts – Flexibility and Redundancy

Plan for flexibility and future growth • Allow extra space in the to add equipment (, , , exhaust fans) • Allow for additional shaft and ceiling space • Size ducts and pipe for spare capacity (inexpensive if done initially)

Module 5 PG39 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

MODULE 5 – SYSTEMS

HVAC

Module 5 PG40 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Systems – HVAC

Laboratory HVAC • Look at three different criteria and choose worst case: • Cooling load (primarily heat generating equipment) • Minimum air change rate • Exhaust requirement • Consider supplemental cooling for high density loads (freezer rooms, etc.)

Module 5 PG41 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Systems – HVAC Laboratory HVAC Design Considerations • “The effect of room air challenge is significant and of the same order of magnitude as the effect of face velocity” • “Consequently, improper design of replacement air supply can have a disastrous effect on the efficiency of a laboratory hood.”

ASHRAE RP-70, Caplan and Knutson, 1977

Module 5 PG42 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Systems – HVAC Laboratory HVAC Design Considerations • “Supply air distribution shall be designed to keep air jet velocities less than half, preferably less than one-third of the capture velocity or the face velocity of the laboratory chemical hoods at their face opening.” ANSI/AIHA Z9.5-2003, section 5.2.2

Module 5 PG43 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Systems – HVAC Laboratory Exhaust Systems • Fan discharge design must minimize risk of re-entrainment • Stack/Intake separation • Stack height • Stack effective height/momentum • Stack discharge velocity must be 3,000 fpm, minimum

Module 5 PG44 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Systems – HVAC

Laboratory Exhaust Systems • Heat Recovery • Air to air plate • Run around loop • Molecular sieve wheel

Module 5 PG45 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Systems – HVAC

Laboratory Exhaust Systems • ANSI/ASHRAE/IESNA 90.1 – 2010 • Prescriptive path requires some combination of VAV and/or heat recovery for most lab HVAC systems • Alternative is Energy Cost Budget Method

Module 5 PG46 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Systems – HVAC

Laboratory Exhaust Systems • ANSI/ASHRAE 62.1 – 2010 • January, 2011 interpretation precludes using any technology for laboratory fume hood or chemical storage room exhaust heat recovery that results in any amount of cross contamination • This appears to disallow the use of total energy recovery wheels • Addendum K is out for public review

Module 5 PG47 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Systems – HVAC

COURTESY OF LABS 21

Module 5 PG48 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Systems – HVAC

How Much Mechanical Space? • Between 8 and 20% of gross building square footage • 8% for simpler academic buildings • 20% for complex labs or buildings with animal areas • Vivariums or BSL containment labs may require 50% of the gross building area for mechanical space

Module 5 PG49 5 HVAC FUNDAMENTALS OF MODERN LAB DESIGN

Module 5 Systems – HVAC

Applicable Standards and Guidelines

Module 5 PG50