designing to prevent disasters: mechanical system failures and physical plant design

Designing to Prevent Disasters: Mechanical System Failures

and Physical Plant Design

Bill Zavatkay PE, LEED AP BD+C – HDRMechanical Engineering Section Manager

A

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Introduction

Disasters

Regulatory Requirements

Physical Plant

2014 ACLAM FORUM: Coeur d’Alene, Idaho

By definition, a disaster is, "an occurrence causing

widespread destruction and distress, a grave

misfortune, a total failure..." A disaster is often

further defined as being either a man-made or

natural event that results in death, injury, and

property damage which cannot be managed

through normal, routine channels.(Source: Google…Author not indicated).

B


Introduction

Disasters


Physical Plant


What we typically think of as a Disaster?


Widespread flooding from levee breaches and storm surge


Wind and flood damage


Wind damage to buildings


Tree damage to buildings


Impassable roads


Natural disasters occur and make big headlines, but more likely events include:

• Facility Failures

• Operational Issues

• Power Outages


Broken Pipes

FiresFailed Equipment

C


Introduction

Disasters


Physical Plant


REGULATORY REQUIREMENTS

Green / Sustainable / LEED / Energy Star / ASHRAE 90.1 =

Building codes / GUIDE / BMBL / WHO / NIH DRM / AALAC / USDA =

• Safety for building occupants as well as “the public”

• Minimum exhaust stack velocities (vs energy savings)• Redundant equipment (increased electrical load)

• Spare capacity (effects on operation energy use)

“SAVE THE PLANET”

“Safety”

Combined equals your Project


THE GUIDE – BASIC HVAC REQUIREMENTS

» Performance Based Approach• Temperature and humidity control to minimize variations.• Pressurization Control – Directional Airflow• HVAC system to be designed for reliability, ease of

maintenance and energy conservation.• Temperature: 68-79 deg F, maintain +\- 2 degrees F (varies

based on species)• Maintain Humidity 30-70% year round.• Redundancy • Temperature control for each holding space.• Emergency power for critical services (HVAC, freezers,

ventilated racks, isolators)


NIH DRM - BASIC HVAC REQUIREMENTS

» Prescriptive Based Approach• Animal Facilities shall meet the requirements of “The Guide”• Laboratory Spaces shall meet the requirements of the

BMBL.• Design conditions: ASHRAE 0.4% summer, 99.6% winter• Equipment sized for 20% future expansion.• 15 ACH Small Animal Static Rack/Large Animal• 10 ACH Small Animal Ventilated Rack• Exhaust fans on emergency power.• Dedicated Air Systems

» Non-Research Function» Animal Areas» Lab General Research.

• N+1 Redundancy Required.• Emergency Power Required; AHU’s, EF, chillers, boilers,

pumps, etc.


THE GUIDE – PAGE 35

Animal facilities may be subject to unexpected conditions that result in the catastrophic failure of critical systems or significant personnel absenteeism, or other unexpected events that severely compromise ongoing animal care and well-being (ILAR 2010). Facilities must therefore have a disaster plan. The plan should define the actions necessary to prevent animal pain, distress, and deaths due to loss of systems such as those that control ventilation, cooling, heating, or provision of potable water. If possible the plan should describe how the facility will preserve animals that are necessary for critical research activities or the irreplaceable. Knowledge of the geographic locale may provide guidance as to the probability of a particular type of disaster.


NIH GUIDELINES

» “Spare” Capacity Issues• Different than redundancy or reliability• Owner driven (program revisions)• NIH DRM requirements for 20% spare capacity• Process loads (large % of total load)• Major equipment turndown Issues

» Chillers» Boilers» AHU Components

• Coils• Filters• Fans• Humidifiers• Airflow Stations

» Exhaust fans

n+1 + 20% =

Potential Loss of

EfficiencyUntil Used

D


Introduction

Disaster Preparedness


Physical Plant


• Every system will fail at the least opportunistic time.

• Design, plan, educate and train to eliminate or provide redundancy for every critical system.

“SINGLE POINT OF FAILURE”


Identify all Critical systems:

MEP Systems:

• Air Handling Units • Exhaust Fans• Cooling • Heating• Controls• Potable Water• Power



MEP Critical systems:

• Need Redundancy• Need Spare Parts• Need Maintenance Staff to Install

Spare Parts



PHYSICAL PLANT Reliability is a measure of probability that the environmental systems will be operational at the time that it is required.

Redundancy is a subset of reliability and can be achieved by the engineering systems, or a combination of engineering systems and protocols

2 at 50%

3 at 33%

4 at 25%


PHYSICAL PLANT

No redundancy Scenario One AHU and one EF serves each zone

Lab Zone

Lab Zone


PHYSICAL PLANT

Partial Redundancy Scenario Requires ductwork and control dampers to allow

interconnection of air systems Requires extensive ceiling space Reduces quantity of equipment to provide

redundancy

Lab Zone

Lab Zone


PHYSICAL PLANT

Lab Zone

Lab Zone

Fully Redundant Scenario – 2N or 2@50% Greater equipment requirements Automatic Operation Less dependency upon other systems


Reliability & Redundancy•independent systems•N+1 (100%) back-up capability

desirable•Less than N+1 with load shedding•consider utilizing systems adjacent to

vivarium spaces as an alternate means to provide redundancy

PHYSICAL PLANT


PHYSICAL PLANT

AHU fan redundancy options Fan Wall Dual Fans


Failure Protection - Automation•normal operation•exhaust failure – supply reacts•supply failure – exhaust reacts•BAS controls & interlocks•maintain directional airflow (positive or

negative pressurization)•consider ‘load shedding’ strategies

PHYSICAL PLANT


Central Utilities (Campus Scenario- Issues)

•Large Chiller Plants typically not on emergency power backup

•Large Boiler Plants typically not on emergency power backup

PHYSICAL PLANT


Central Utilities (Campus Scenario-Resolutions)

•Consider providing small backup air cooled chiller and pumps for critical cooling.

•Consider providing small backup boiler and pumps for critical heating

PHYSICAL PLANT

https://www.google.com/url?q=http://withfriendship.com/user/crook/chiller.php&sa=U&ei=Mx5nU_KlB8aCogS6_4CoBA&ved=0CDoQ9QEwBg&usg=AFQjCNHC_SJhJiZ9Y-hJrEVnX6hpuCz4Fg


Potable Water

•Consider providing potable water backup storage tank if water outage typical.•Provide maintenance staff on hand to repair pipe leaks.•Ensure shut-off valves are in place in case of emergency.•Periodically exercise valves to ensure they will be operational when required.

PHYSICAL PLANT


Normal Power•Redundant Feeders to a double ended substation•Redundancy and independent

electric services•Should come from two separate

utility generating stations (Or from two separate substations on a campus configuration)

•Feeders should be in separate duct banks and routing.

•Provides redundancy in feeders and in services to building.

PHYSICAL PLANT - POWER


EM Power•Generators•Serve critical equipment•Supply air handlers•Exhaust fans•Caging systems (IVCs)•Heating & Cooling systems•Distribution pumps•BAS system controllers

UPS•BAS control panels to keep from resetting controls to minimize downtime under any failure scenario

PHYSICAL PLANT - POWER

https://www.google.com/url?q=http://catgensets.blogspot.com/&sa=U&ei=_GVWU5mvCo-62gXYyYGoDw&ved=0CEwQ9QEwDw&usg=AFQjCNH4Bg24jYpXA5dWdGcosV67t43rdQ


PHYSICAL PLANT…

Locate vivarium above flood elevation levels – New facilities

» Flood gates or retaining walls around existing facilities

Locate physical plant above flood elevation levels

Locate electrical switchgear above floor elevation levels


PHYSICAL PLANT…

Provide adequate level of redundancy

Provide automated control

Provide Emergency Power Backup

Locate generators above flood elevation level

Provide “enough” fuel capacity for sustained duration for outage based on risk assessment


PHYSICAL PLANT… Fail closed reheat coil valves

Fail open AHU preheat valve

Fail open AHU cooling coil valves

Interlock AHU’s with EF’s

Interlock supply and exhaust air valves

Security systems to prevent unwanted entry

Seismic reinforcement

https://www.google.com/url?q=http://www2.emersonprocess.com/en-us/news/pr/pages/806-sil3valves.aspx&sa=U&ei=rPJGU8nDO5LK0AHr54DoDg&ved=0CDIQ9QEwAQ&usg=AFQjCNHqdH1w_RC_dEpOPvFtkTOJMrkV2w


PHYSICAL PLANT…

Snowfall issues and AHU shutdowns


PHYSICAL PLANT…

Provide snow melt device such as MISTOP Snostop

Provide bypass damper across filters that opens on high filter delta P

Remove AHU pre-filters before snow occurrences


PHYSICAL PLANT – MAINTENANCE

• Access Outside Vivarium

• Locate Equipment where it is accessible

• Routine Inspection

• Preventative Maintenance

• Minimize Impact on Science

• High Tech vs. Low Tech

https://www.google.com/url?q=http://www.h3mc.com/&sa=U&ei=jPFGU-yqF8Od0AGP-4CwDw&ved=0CDYQ9QEwBA&usg=AFQjCNH9OKzf4rX08O36BlzvywOxSFMT2w


THE BIODESIGN INSTITUTE AT ASU


PHYSICAL PLANT


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designing to prevent disasters: mechanical system failures and physical plant design

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