Ventilation Topics Stakeholder Meeting 3 - HMGh-m-g.com/T24/.../2-T24_ASHRAE-Vent-StakMtg3_Presentation_4.5.2011.pdfVentilation Topics Stakeholder Meeting 3 Taylor Engineering Energy

California Statewide Utility Codes and Standards Program

Ventilation TopicsStakeholder Meeting 3

Taylor Engineering Energy Solutions

April 5, 2011

Call In Number: (661) 705-2010

Access Code: 46701#

CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

January 19, 2011

2

CA Utilities 2013 Title 24 Stakeholder Meeting for Proposed Code Changes

Agenda

1:00–1:15 Introductions1:15–2:10 Garage Ventilation2:10–3:00 Kitchen Ventilation3:00 -3:50 Lab Exhaust


January 19, 2011

3


IOU Support for 2013 Title 24

● The California Investor Owned Utilities (IOUs) are actively supporting the California Energy Commission (CEC) in developing the state’s building energy efficiency code (Title 24)

● Their joint intent is to achieve significant energy savings through the development of reasonable, responsible, and cost-effective code change proposals for the 2013 code update and beyond

● As part of the IOU effort, at the request of the CEC, we are hosting stakeholder meetings to get industry input and feedback on our code change proposals


January 19, 2011

4


Requirements for a Successful Code Change

● For base code, a measure must:● Be cost-effective

● based on the standards-induced additional first cost, maintenance costs, measure life, and energy cost savings

● typically according to the Time Dependent Valuation (TDV) life-cycle costing methodology and weather data to be provided by the California Energy Commission

● Be possible to implement using equipment that is available from multiple providers or that is reasonably expected to be available following the code change


January 19, 2011

5


IOU Stakeholder Meetings Process

● Typically holding three meetings:● First: present scope, request data

● Code change direction and possible options

● Methodology

● Best practices, market data

● Second: present findings● Results of data collection and analysis

● Cost effectiveness

● “Strawman” proposed code language

● Third/final: present proposed code language● Will post code change language online in advance

● May hold phone/webinar meetings depending on feedback

● CEC’s pre-rulemaking workshops being scheduedfor April/May


January 19, 2011

6


Submitting Comments

● Informal Comment Process● Comments can be submitted to CASE authors,

substantive comments will receive responses

● Questions and responses will not be posted online, but common or frequent questions will be communicated as necessary between stakeholders

● The team will work with stakeholders to resolve issues as best we can

● The CEC has a formal comment process during later stages of the official rulemaking process


January 19, 2011

7


Schedule: Key Dates

● March 2010 – March 2011● CEC develop foundation /methodology● IOUs conduct research and analysis, and present results at

stakeholder meetings

● Feb - March 2011● IOUs finalize code change proposals for submittal to CEC

● April – June 2011● CEC conducts pre-rulemaking work shops

● Sept 2011 – Feb 2012● CEC Rulemaking Activities, 45 Day Language

● March 2012● Title 24 Adoption date

● January 1, 2014● Title 24 Effective date


January 19, 2011

8


Meeting Protocols

● Please DO NOT place your phone on HOLD● Please mute your microphone, unless you are

speaking● Ask questions/comment by “chat” or by voice● We want to hear your concerns

● Opposing viewpoints are encouraged

● Time is limited● Clearly state your name and affiliation prior to speaking

● Minutes and presentation material will be available online – we will distribute link


Garage VentilationStakeholder Meeting 3

Taylor Engineering, LLCEnergy Solutions

April 5, 2011


April 5, 2011

2


2010 CMC403.8.2 Alternative Exhaust Ventilation for Enclosed Parking Garages.

Mechanical ventilation systems used for enclosed parking garages shall be permitted to operate intermittently where the system is arranged to operate automatically upon detection of vehicle operation or the presence of occupants by approved automatic detection devices.

403.8.2.1 Minimum Exhaust Rate. Ventilation systems shall be capable of providing 14,000 cfm (6608 L/s) of exhaust air for each operating vehicle. Number of operating vehicles shall be determined based on 2.5 percent of all parking spaces (and not less than one vehicle).

403.8.2.2 Automatic Carbon Monoxide Sensing Devices. Automatic carbon monoxide sensing devices may be employed to modulate the ventilation system to maintain a maximum average concentration of carbon monoxide of 50 parts per million during any eight-hour period, with a maximum concentration not greater than 200 parts per million for a period not exceeding one hour. Automatic carbon monoxide sensing devices employed to modulate parking garage ventilation systems shall be approved pursuant to the requirements in Section 302.1.

ASHRAE 8 – Garage Ventilation


April 5, 2011

3


Proposed Code Change – Title 24Enclosed Parking Garages. Mechanical ventilation systems for enclosed parking

garages where the total design exhaust rate for the garage is greater than or equal to 10,000 cfm shall conform to all of the following:

1. Automatically detect contaminant levels and stage fans or modulate fan airflow rates to 50% or less of design capacity provided acceptable contaminant levels are maintained

2. Have controls and/or devices that will result in fan motor demand of no more than 30 percent of design wattage at 50% of design airflow

3. CO shall be monitored with at least one sensor per 5,000 ft2, with the sensor located in the highest expected concentration locations, with at least two sensors per proximity zone. A proximity zone is defined as an area that is isolated from other areas either by floor or other impenetrable obstruction.

4. CO concentration at all sensors is maintained ≤ 25 ppm at all times.

5. The ventilation rate shall be at least 0.15 cfm/ft2 when the garage is scheduled to be occupied.

6. The system shall maintain the garage at negative or neutral pressure relative to other occupiable spaces when the garage is scheduled to be occupied.



April 5, 2011

4


Proposed Code Change – Title 247. CO sensors shall be:

1. Certified by the manufacturer to be accurate within plus or minus 5% of measurement.

2. Factory calibrated.

3. Certified by the manufacturer to drift no more than 5% per year.

4. Certified by the manufacturer to require calibration no more frequently than once a year.

5. Monitored by a control system. The system shall have logic that automatically checks for sensor failure by the following means. Upon detection of a failure, the system shall reset to design ventilation rates and transmit an alarm to the facility operators.

a. If any sensor has not been calibrated according to the manufacturer’s recommendations within the specified calibration period, the sensor has failed.

b. During unoccupied periods the systems compares the readings of all sensors. If any sensor is more than 30% above or below the average reading for a period of longer than 4 hours, the sensor has failed.

c. During occupied periods the system compares the readings of sensors in the same proximity zone. If any sensor in a proximity zone is more than 30% above or below the average reading for a period of longer than 4 hours, the sensor has failed.

Exception: Any garage where more than 20% of the vehicles expected to be stored in the garage or in a specific part of the garage are nongasoline fueled.



April 5, 2011

5


Other Energy Codes● Oregon Energy Code (goes into effect July 2011)

● Requires CO control for garages > 30,000 design cfm

● Control CO to < 50 ppm during any 8-hour period, < 200 ppm for a period not exceeding 1 hour

● System must be capable of ventilating at 1.5 cfm/sqft

● Failure of devices causes the exhaust fans to operate in the ON position● No criteria about what qualifies as a failure

● Washington Energy Code (2009)● Requires CO control, time clocks, and occupancy sensors for garages >

8,000 design cfm

● Control CO to < 35 ppm. Spacing and location of sensors per manufacturer’s recommendations

● For garages with >20% nongasoline vehicles, fuel-appropriate sensors are required. Concentration level setpoint must be no less than the standard used by OSHA for 8-hour exposure



April 5, 2011

6


Typical Practice● Most new garages have DCV with CO

● Generally sold with a maintenance program

● Some sensors turn themselves off after 2 years if not calibrated

● Many existing garages are constant volume● Many of these have arbitrary fan schedules

● e.g. fans operate from 7am to 9am and from 4pm to 6pm

● Note that when garage fans are turned off stack effect sucks garage air into the building above



April 5, 2011

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Findings● Sensor Accuracy

● CO sensors use electrochemical and solid state sensors that have been used in critical life safety and industrial applications for over 60 years (e.g. mines)

● Not same technology as CO2 sensors

● Recent studies:

● 26 sensors in garages showed ~5% drift/yr after 2 years

● Taylor Engineering study shown later

● UL conducted a study on residential sensors over a period of four years. Overall they found the sensors to be very reliable (residential sensors must meet UL Std 2034)

● Garages use an array of sensors and control to the highest signal so failure of a single sensor has little risk



April 5, 2011

8


Estimated Energy Savings● Energy savings based on trend reviews of actual garages with CO

monitoring systems



April 5, 2011

9


Estimated Energy Savings● Trend reviews done on two garages with systems installed.

● Result: 80 – 90% fan energy savings



April 5, 2011

10


Estimated Cost● Product, installation, and maintenance costs from manufacturers

(with markup)


Product CostsCO sensor $250 $/CO sensorController (<32 sensors) $3,000 $/controllerController (> 32 sensors) $4,000 $/controllerVFD $2,568 $/VFD (assume 1 per 10,000 cfm)

Installation costsTotal sensor installation $1,200 $/sensor for system installationVFD $545 $/VFD (assume 1 per 10,000 cfm)

Maintenance costsReplace CO sensor $50 $/sensor/yearLabor to calibrate CO sensor $50 $/sensor/yearMaterials for CO calibration $38 average


April 5, 2011

11


Cost Effectiveness

● Calculated for CZ03

● Cost-effective for all garages greater than 6,000 cfm (15-year life).


$0.00

$0.50

$1.00

$1.50

$2.00

$2.50

$3.00

$3.50

$4.00

$4.50

$5.00

2,500 5,000 7,500 10,000 15,000 25,000 37,500 50,000 100,000 200,000 400,000

$/cfm

Design Ventilation Airflow (cfm)

15‐year Life‐Cycle CostBasecase

Proposed Measure


April 5, 2011

12


CO Sensor Field Study● Testing sensors already installed in garages to see how they perform

at various CO concentration levels.

● Garage 1: 5/5 sensors failed

● Garage 2: 4/5 sensors failed


volts ppm volts ppm volts ppm volts ppm volts ppmSensor 1 0.45 9 2.29 45.8 1.2 - 0 - 0.99 - 0 - 0.6 - 0 - failedSensor 2 0.39 7.8 0.24 4.8 0.24 4.8 0.23 4.6 0.23 4.6 failedSensor 3 0.44 8.8 0.24 4.8 0.24 4.8 0.24 4.8 0.25 5 failedSensor 4 0.49 9.8 2.28 45.6 2.29 45.8 2.29 45.8 2.29 45.8 failedSensor 5 0.42 8.4 0.23 4.6 0.23 4.6 0.23 4.6 0.23 4.6 failed

Conclusion0 ppm 35 ppm 50 ppm 100 ppm 200 ppm

volts ppm volts ppm volts ppm volts ppm volts ppmSensor 1 0.98 0.63 0.98 1 0.98 1 0.98 1 0.98 1 failed

Sensor 2 0.98 0.62 2.33 85 2.67 106 3.02 128 3.28 144operating but out of calibration

Sensor 3 0.98 0.00 0.98 0 0.98 0 0.98 0 0.98 0 failedSensor 4 0.99 0.00 0.99 0 0.99 0 0.99 0 0.99 0 failedSensor 5 0.98 0.00 0.98 0 0.98 0 0.98 0 0.98 0 failed

Conclusion100 ppm 200 ppm0 ppm 35 ppm 50 ppm


April 5, 2011

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CO Sensor Field Study● Garage 3: 5/5 sensors performing well

– All sensors are responsive. The readings that are more than a few % off are reading too high (err on the side of safety).


0 ppm

ppmmeasured

ppm% Diff of

Full Scalemeasured

ppm% Diff of

Full Scalemeasured

ppm% Diff of

Full Scalemeasured

ppm% Diff of

Full ScaleSensor 1 0 31 -2% 49 0% 104 2% 200 0%Sensor 2 0 30 -2% 46 -2% 102 1% 210 4%Sensor 3 0 33 -1% 47 -1% 250 60% 248 19%Sensor 4 0 35 0% 53 1% 114 6% 206 2%Sensor 5 0 40 2% 62 5% 139 16% 241 16%

35 ppm 50 ppm 100 ppm 200 ppm


April 5, 2011

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Acceptance Tests● Observe that fans are at minimum speed and fan motor demand is no more than

30 percent of design wattage

● Apply CO span gas with a concentration of 30 ppm one by one to 50% of the sensors but no more than 10 sensors per garage. For each sensor tested observe:● CO reading is between 28 and 32 ppm

● Ventilation system ramps to full speed when span gas is applied

● Ventilation system ramps to minimum speed when span gas is removed.

● Temporarily override the programmed sensor calibration/replacement period to 5 minutes. Wait 5 minutes and observe that fans ramp to full speed and an alarm is received by the facility operators. Restore calibration/replacement period.

● Temporarily place the system in unoccupied mode and override the programmed unoccupied sensor alarm differential from 30% for 4 hours to 1% for 5 minutes. Wait 5 minutes and observe that fans ramp to full speed and an alarm is received by the facility operators. Restore programming.

● Temporarily override the programmed occupied sensor proximity zone alarm differential from 30% for 4 hours to 1% for 5 minutes. Wait 5 minutes and observe that fans ramp to full speed and an alarm is received by the facility operators. Restore programming.



April 5, 2011

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ACM Simulation Baseline● Garage fan schedule follow building schedule

● If the proposed garage < 10,000 cfm or if the garage is expected to serve more than 20% diesel vehicles then basecase garage fan power = 0.35 W/cfm● based on 1.5” total static and 50% fan efficiency

● If proposed garage > 10,000 cfm and less than 20% diesel then basecase fan power is fixed at 0.044 W/cfm● based on 1.5” total static, 50% fan efficiency and an average fan

speed of 50%



April 5, 2011

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Conclusions

● Older garages may not be maintained well. Sensors are not calibrated when required and consequently fail.

● Newer systems that are maintained work well.

● We can ensure quality sensors are installed and maintained by being specific in the code about accuracy and maintenance of the system.



April 5, 2011

17


QUESTIONS & COMMENTS


Jeff [email protected]

510-263-1547


1

Kitchen Ventilation ProposalsStakeholder Meeting #3

Taylor EngineeringEnergy Solutions

April 5, 2011


04/05/2011CA Utilities 2013 Title 24 Stakeholder Meeting for Proposed Code Changes

22

ASHRAE 5 – Kitchen VentilationAgenda● Current Code – T24, 90.1

● Proposal 1 –Scope and Definitions

● Proposal 2 – No Short Circuit Hoods

● Proposal 3 – Must Use Available Transfer Air

● Proposal 4 – Maximum Hood CFMs

● Proposal 5 – Required Energy Features: DCV, or ERV, or…

● Proposal 6 – Acceptance Testing



33

ASHRAE 5 – Kitchen VentilationCurrent Code Requirements● No Current Kitchen Ventilation Requirements in T24

● ASHRAE 90.1-2007:

● Kitchen Hoods. Individual kitchen exhaust hoods larger than 5000 cfm shall be provided with makeup air sized for at least 50% of exhaust air volume that is

● unheated or heated to no more than 60°F and

● uncooled or cooled without the use of mechanical cooling.

● ASHRAE 90.1-2010:

● Major changes from 90.1-2007

● The proposed requirements on the following slides are the same as 90.1-2010 with minor changes



44

ASHRAE 5 – Kitchen VentilationProposal 1 –Scope and DefinitionsScope

● Make it clear that kitchen ventilation cannot use the process exception

Nonresidential Standard Section 3.2 DefinitionsAdd new terms:

● Makeup Air = direct OA into kitchen

● Transfer Air = air from nearby zone (e.g. dining)

● Replacement Air = makeup + transfer + infiltration

● Other necessary terms listed in ASHRAE Standard 154



5

ASHRAE 5 – Kitchen Ventilation

Proposal 2 – Direct Replacement of Hood Exhaust Air Limitation: Code Statement

Proposed Code Statement:Replacement air introduced directly into the hood cavity of kitchen exhaust hoods shall not exceed 10% of the hood exhaust airflow rate.



6


Proposal 2 – Direct Replacement of Hood Exhaust Air Limitation: Rationale

● AGA and CEC have shown direct supply greater than 10% of hood exhaust in Short-circuit Hoods significantly reduces Capture and Containment (C&C)

● Poor C&C does not remove cooking heat and smoke from kitchen

● Exhaust rates generally higher to offset poor C&C

● Higher exhaust fan energy

● Higher Exhaust rates increase Room Makeup Air rates

● Higher MUA fan and conditioning energy



7


Proposal 2 – Direct Replacement of Hood Exhaust Air Limitation: Analysis

● Lifecycle Cost Analysis ComparingA. Short-circuit exhaust system

B. Equally effective C&C Non-short-circuiting hood system

● Equipment Cost and Power Differential

(Cost Data provided by equipment vendors)

1,500 CFM Exhaust Only Hood System 3,000 CFM Short-circuit Hood

Hood Cost $ 1,339 Hood Cost $ 2,283 Exhaust Fan Cost $ 700 Exhaust Fan Cost $ 816

Additional MUA Cost $ 544 Total $ 2,039 Total $ 3,643

Cost Difference $ 1,604

1,500 CFM Exhaust Only Hood System 3,000 CFM Short-circuit HoodBHP BHP

1,500 CFM Exhaust Only Hood 0.405 3,000 CFM Short-Circuit Hood 0.9351,500 CFM MUA 0.302

Total 0.405 Total 1.237

BHP Difference 0.83 hp



8


Proposal 2 – Direct Replacement of Hood Exhaust Air Limitation: Statewide Savings

● Short-circuit Hoods represent approximately:● 20% of U.S. Market

● 1% of California Market



9ASHRAE 5 – Kitchen Ventilation

Proposal 3 – Conditioned Makeup Air Limitations: Code Statement

Mechanically cooled or heated makeup air delivered to any space with a kitchen hood shall not exceed the greater of:

a) The supply flow required to meet the space heating and cooling load

b) The hood exhaust flow minus the available transfer air from adjacent spaces.

Available transfer air is that portion of outdoor ventilation air serving adjacent spaces not required to satisfy other exhaust needs, such as restrooms, not required to maintain pressurization of adjacent spaces, and that would otherwise be relieved from the building.




Proposal 3 – Conditioned Makeup Air Limitations: Rationale

● Supplying conditioned makeup air when transfer air is available is a wasteful design practice and should be prohibited.

● Using available transfer air saves energy and reduces the first cost of the kitchen makeup unit and the exhaust system in the adjacent spaces.

● A previous version of this proposal did not allow makeup air if 100% transfer air was available (i.e. a recirc unit was required for conditioning). It turns out, however, that a MAU unit is more efficient than a recirc unit so this version of the proposal is now the same as the 90.1 requirement. This is more efficient because of the many economizer hours available in our climate.




Proposal 3 – Conditioned Makeup Air Limitations: DCV● Note that the dining room is exempt from

the DCV requirement per: ● EXCEPTION 2 to Section 121(c)3: Where space

exhaust is greater than the design ventilation rate specified in Section 121(b)2B minus 0.2 cfm per ft 2 of conditioned area.

● We will clarify in the users manual that "space exhaust" includes kitchen hood exhaust in adjacent spaces.


Proposal 3 – Conditioned Makeup Air Limitations: System Schematic


12

GREASE EXHAUST:5,000 CFM

KITCHEN DINING

SUPPLY AIR:10,000 CFM

TOILETEXHAUST:500 CFM

SUPPLY AIR TO COOL KITCHEN AT 55F: 2,000 CFM

MIN OA:5,500 CFM

AVAILABLE TRANSFER AIR:5,000 CFM

(KITCHEN MIN OA: 500 CFM)




13


KITCHEN DINING


OUTSIDE AIR:2,000 CFM

TOTALEXHAUST:2,500 CFM


MIN OA:5,500 CFM

RECIRCULATED AIR:0 CFM

TRANSFER AIR:3,000 CFM

(KITCHEN MIN OA: 500 CFM)OPTION 1: MAU = COOLING CFM




14


KITCHEN DINING


OUTSIDE AIR:0 CFM



MIN OA:6,000 CFM

RECIRCULATED AIR:2,000 CFM

TRANSFER AIR:5,000 CFM

(KITCHEN MIN OA: 500 CFM)OPTION 2: RECIRC ONLY




15


KITCHEN DINING


OUTSIDE AIR:5,000 CFM



MIN OA:5,500 CFM

RECIRCULATED AIR:0 CFM

TRANSFER AIR:0 CFM

(KITCHEN MIN OA: 500 CFM)NOT ALLOWED: MAU = HOOD CFM




Proposal 3 – Conditioned Makeup Air Limitations: Cost Analysis● Cost Analysis Comparison

● Examine the makeup heating/cooling energy costs at all transfer rates

● Analyze a typical kitchen exhaust and heating/cooling scenario

● Markets: San Francisco, Sacramento, Riverside

● Cooling CFM: 2,000 cfm

● Exhaust CFM: 10,000 cfm

● Most Cost Effective when transfer CFM equals Exhaust CFM minus COOLING CFM


Proposal 3 – Conditioned Makeup Air Limitations: Analysis


17

$-

$2,000

$4,000

$6,000

$8,000

$10,000

$12,000

$14,000

0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100%

Transfer CFM = Exhaust CFM – Cooling CFM

100% TRANSFER EQUIVALENT TO 100% RECIRCULATION COOLING

PERCENT OF TRANSFER AIR

AN

NU

AL

KIT

CH

ENC

OO

LIN

G/M

AK

EUP

AIR

UN

IT E

NER

GY

RIVERSIDE

SACRAMENTO

SAN FRANCISCO




Proposal 3 – Conditioned Makeup Air Limitations: Statewide Savings

● Current estimated number of restaurants in California by type:● 30,000 quick serve restaurants (e.g. McDonalds)

● 30,000 full serve restaurants (e.g. Applebee’s)

● 30,000 institutional kitchens (e.g. school cafeterias)

● Estimated CA: 178M sf Food Service, 276M Exh CFM.

● Estimated that 2.75 million square feet of kitchen is being built per year

● Estimated 15% savings in makeup fan electrical usage and demand using available transfer air

● Estimated savings of 50% when heating and cooling energy savings are included




Proposal 4 – Exhaust Hood Airflow Limitations: Code StatementProposed Code Statement:● Type I Exhaust Hood Airflow Limitations. For

kitchen/dining facilities having total Type 1 and Type II kitchen hood exhaust airflow rates greater than 5,000 cfm, each Type 1 hood shall have an exhaust rate that complies with Table 1. If a single hood, or hood section, is installed over appliances with different duty ratings, then the maximum allowable flow rate for the hood or hood section shall not exceed the Table 4 values for the highest appliance duty rating under the hood or hood section. Refer to the ASHRAE Standard 154 for definitions of hood type, appliance duty, and net exhaust flow rate.




Proposal 4 – Exhaust Hood Airflow Limitations: Code Statement

Proposed Code Statement:

Table 4: Maximum Net Exhaust Flow Rate, CFM per Linear Foot of Hood Length

Type of Hood Light Duty Equipment

Medium Duty Equipment

Heavy Duty Equipment

Extra Heavy Duty Equipment

Wall-mounted Canopy

140 210 280 385

Single Island 280 350 420 490

Double Island 175 210 280 385

Eyebrow 175 175 Not Allowed Not Allowed

Backshelf/Pass-over

210 210 280 Not Allowed

●Exceptions:75% of all the replacement air is transfer air that would otherwise be exhausted.




Proposal 4 – Exhaust Hood Airflow Limitations: Rationale

● Exhaust airflow rates in Table 4 are 30% below the minimum airflow rates in ASHRAE Standard 154-2003, which are for unlisted hoods

● Values in Table 4 are supported by ASHRAE RP-1202 for listedhoods

● Intended to eliminate wasteful common practice of specifying excessive exhaust airflow by selecting hoods that are not listedor have not been subjected to a recognized performance test

● Should not increase first cost and in many cases will reduce first cost through downsizing of exhaust, supply and cooling equipment




Proposal 4 – Exhaust Hood Airflow Limitations: Planned Analysis● Lifecycle Cost Analysis Comparing

● BASE CASE: Hood design using unlisted hood and code minimum (ASHRAE Standard 154 rates) exhaust rates

● PROPOSED CASE: Hood design using listed hood and 30% better than ASHRAE Standard 154 Rates

● EQUIPMENT COSTS SAVINGS:

● FAN ENERGY COST SAVINGS (Excluding Heating/Cooling Savings)

Exhaust Exhaust Exhaust MakeupHood Hood Fan Unit NetCFM Cost Cost Cost Cost

Unlisted Hood System, ASHRAE Std 154 5,550 $1,300 $2,090 $16,830 $20,220Listed Hood System, 30% Better than Std 154 3,850 $1,300 $1,463 $11,781 $14,544

Exhaust Exhaust Makeup Annual Hood Hood Unit ElectricalCFM HP HP Costs

Unlisted Hood System, ASHRAE Std 154 5,500 2.98 4.37 $3,552Listed Hood System, 30% Better than Std 154 3,850 2.32 1.88 $2,029

(Equipment selections and costs provided by equipment vendors)




Proposal 5 – Makeup Airflow Limitations: Code StatementIf a kitchen/dining facility has a total kitchen hood exhaust airflow rate greater than 5,000 cfm then it shall have one of the following: a)At least 50% of all replacement air is transfer air that would otherwise be exhausted.b)Demand ventilation system(s) on at least 75% of the exhaust air. Such systems shall:

a) Include controls necessary to modulate airflow in response to appliance operation and to maintain full capture and containment of smoke, effluent and combustion products during cooking and idleb) Include failsafe controls that result in full flow upon cooking sensor failurec) Allow occupants the ability to temporarily override the system to full flowd) Be capable of reducing exhaust and replacement air system airflow rates to the larger of:

a) 50% of the total design exhaust and replacement air system airflow rates b) The ventilation rate required per Section 121

c)Listed energy recovery devices with a sensible heat recovery effectiveness of not less than 40% on at least 50% of the total exhaust airflow.d)A minimum of 75% of makeup air volume that is:

a. Unheated or Heated to no more than 60°Fb. Uncooled or Cooled without the use of mechanical cooling.



24

ASHRAE 5 – Kitchen VentilationProposal 5 – Makeup Airflow Limitations: Demand Control Ventilation Systems (DCV)



25

ASHRAE 5 – Kitchen VentilationProposal 5 – Makeup Airflow Limitations: Demand Control Ventilation Systems (DCV)●Common Kitchen Exhaust Systems●Typical control strategy: ON/OFF, Exhaust and Makeup Air fans full speed or off ●Reality:

● Food not being cooked at all times● Peak exhaust requirements not necessary at all times● Fans often run 24/7 to avoid fire alarms when operators forget to turn on

the hood

●DCV Exhaust Systems (e.g. – Melink, Halton MARVEL, CaptiveAire EMS)●Reduce exhaust and make up air fan speeds●Use sensors to determine min. exhaust required for C&C●In the event the operator forgets to turn the fan switch on in the morning, the system will automatically turn on as the duct temperature rises above 90F degrees. Similarly, the system will automatically turn off as the temperature drops below 75F.




Proposal 5 – Makeup Airflow Limitations: Planned Analysis● Lifecycle Cost Analysis Comparing

● Base case: A kitchen system based on a non-modulating exhaust airflow and non-modulating makeup airflow

● Proposed case: A kitchen system based on a modulating demand control exhaust airflow and modulating makeup airflow

● Data Required● Use the real life case studies presented in “Demand Control

Ventilation for Commercial Kitchen Hoods”, SCE/FSTC, 2009● Based on Melink installations in El Pollo Loco, Panda Express,

and Farmer Boys restaurants, Desert Springs Marriot, Westin Mission Hills

● Study includes installation costs, measured energy savings, and estimates of incremental maintenance costs for DCV


Proposal 5 – Makeup Airflow Limitations: Cost Analysis – El Pollo Loco● Test Case: El Pollo Loco, El Monte, CA

● Retrofit Melink DCV with Variable Volume Exhaust Hood and Makeup Air System in Quick Service application.

● Retrofit Costs: $15,500 for 2 DCV Hoods (Est. New Construction Cost with Mature DCV market: $11,625)

● Annual Fan Savings: 9,871 kWh per year (Exhaust and Makeup fan savings only)

● Annual Fan Savings (@ 2010 TDV $0.17): $1,678

● Est. Annual Maintenance (Sensors, VFD’s): $400

● Simple Payback using Retrofit Construction Costs: 12.13 years

● Simple Payback using Est. New Construction Costs: 9.10 years

● This is a Worst Case Scenario. (i.e.-Retrofit, Low HP, Low Diversity, excluding heating/cooling savings)

● Shorter payback in new construction, High HP, High diversity applications.(e.g. – Hotels)


27


Proposal 5 – Makeup Airflow Limitations: Measured Demand Reduction – El Pollo Loco


28

● Exhaust Fan and Makeup Air Unit Electrical Demand Before and After the DCV Retrofit. No Heating/Cooling Savings.


Proposal 5 – Makeup Airflow Limitations: Installation Costs and Savings Summary– All Sites


29

El Pollo Lo

co (Q

uick, Retrofit)

Pand

a Express (Quick, N

ew Con

str.)

Farm

er Boys (Quick, N

ew Con

str.)

Desert Springs M

arrio

t (Ho

tel, Retrofit)

Westin

Mission Hills (H

otel, Retrofit)

Installation Costs ($) $15,500 $8,000 $9,000 $28,000 $22,000Annual Fan Energy Cost Savings (Avg.TDV $0.17/kWh) $1,678 $2,560 $1,340 $25,532 $10,275Est. Installation Costs for New Const. & Mature Technology $11,625 $6,800 $7,650 $21,000 $16,500Annual Maintenance Costs ($) $400 $400 $600 $1,200 $600Simple Payback Inc Maintenance (Years) 9.10 3.15 10.33 0.86 1.71



30


ACM – Simulation Baseline

● Baseline MAU shall be 100% OA , direct evap. only if space temp exceeds 80F less than 10 hrs/yr.

● 90% direct evap effectiveness, 1.5” TSP, 60% fan effic.

● Sized for total exhaust

● Otherwise MAU shall be DX sized for larger of:

● Cooling cfm

● Total exhaust minus available transfer

● Available transfer = the building minimum outside airflow less any exhaust airflows (not including the kitchen exhausts) and 0.05 cfm/sf for exfiltration.

● Total exhaust shall be:

● Proposed case total if less than 5000 cfm

● Table 4 rates if total is over 5000 cfm (user to input lineal feet of hood type and duty)

● If baseline does not qualify for direct evap or 50% transfer air (per above) then baseline shall include DCV on 75% of total exhaust

● Defined fan fractional schedule for DCV

● Defined fan schedule for on/off



31


Acceptance / Functional Testing: Rationale

● This section is fundamental to the kitchen exhaust system commissioning and performance verification which protects public health and safety.

● Hood systems are a field assembly of various components including hoods, fans, replacement air systems, duct and distribution systems and require testing once installed to assure specified system performance is met.

● This section requires verification of hood system performance and operation, and supports Title 24 Acceptance Test purpose and scope.

CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAMASHRAE 5 – Kitchen Ventilation

Acceptance / Functional Testing: Construction Inspection

NR & R APPENDICES – NA7.5.15 (Functional Tests)The following shall be added to the NR Compliance Manual in the NA7 section

NA7.5.15 Kitchen Exhaust Systems with Type I Hood SystemsThe following acceptance tests apply to commercial kitchen exhaust systems with Type

I exhaust hoods. All Type I exhaust hoods used in commercial kitchens shall be tested.

NA7.5.15.1 Kitchen Exhaust Construction InspectionPrior to Functional Testing, verify and document the following

● Exhaust and Makeup Air Systems installed, power is installed and control systems such as demand control ventilation are calibrated

● Set all kitchen hoods, makeup air and transfer systems to Design Airflows

i. Sum and Record all Type I Kitchen Hood Exhausts.

ii. Sum and Record all other Kitchen Exhausts

iii. Sum and Record all Makeup Air Systems

iv. Sum and Record all Transfer Air Systems


32


Acceptance / Functional Testing: Construction Inspection: Systems without DCV

NA7.5.15.2.1 Functional Testing - Exhaust Systems without Demand Control Ventilation 1. Operate all sources of outdoor air providing makeup air for the hood

2. Operate all sources of recirculated air providing conditioning for the space in which the hood is located

3. Operate all appliances under the hood at operating temperatures

4. Verify capture and containment by observing smoke or steam produced by actual cooking operation and/or by visually seeding the thermal plume using devices such as smoke candles or smoke puffers. Smoke bombs shall not be used (note: smoke bombs typically create a large volume of effluent from a point source and do not necessarily confirm whether the cooking effluent is being captured). For some appliances (e.g., broilers, griddles, fryers), actual cooking at the normal production rate is a reliable method of generating smoke). Other appliances that typically generate hot moist air without smoke (e.g., ovens, steamers) need seeding of the thermal plume with artificial smoke to verify capture and containment.

5. If necessary, adjust Type I exhaust hood airflow rates until the thermal plume and smoke is completely captured and contained within the hood. Record the Final Exhaust Airflow Rate.

i. If necessary to improve hood performance and if applicable, add hood side panels, rear seal (back plate), increase hood overhang by pushing equipment back, and relocate supply outlets to improve the capture and containment performance. Repeat Step 2b.

1. Record measures taken to improve performance and Final Exhaust Airflow Rate.

6. Adjust Makeup Air volumes to match final Exhaust air setting. Record the Final Maximum Makeup Airflow Rate.


33


Acceptance / Functional Testing: Construction Inspection: Systems with DCVNA7.5.15.2.2 Functional Testing - Exhaust Systems with Demand

Control Ventilation1. Set all kitchen hoods, makeup air and transfer systems to

Design Minimum Airflows

2. Turn on one of the appliances on the line and bring to operating temperature. Confirm DCV system switches from "off" to the minimum 50% flow setpoint.

3. Operate all appliances at typical conditions. Apply sample cooking products and/or utilize smoke puffers as appropriate. Confirm hood maintains capture and containment during ramping to and at full-speed according to Step 4 in NA7.5.15.2.1 above.

4. Make any necessary modifications and record values according to Step 5 in NA7.5.15.2.1


34



35

ASHRAE Measures –Kitchen Ventilation


Contact Jeff Stein at Taylor [email protected]

510-263-1547


ASHRAE 1 – Lab ExhaustStakeholder Meeting 3

Taylor Engineering, LLCEnergy Solutions

April 5, 2011


April 5, 2011

2


Overview● Two Measures:

● VAV Supply and Exhaust at the Zone Level● Energy Recovery (Run Around Coils)

ASHRAE 1 – Lab Exhaust


April 5, 2011

3


Proposed Code ChangesASHRAE 1 – Lab Exhaust


April 5, 2011

4



Add fan power limit and exception for lab exhaust components from 90.1


April 5, 2011

5




April 5, 2011

6



Add exception for constant volume exhaust where required by code, AHJ or the facility EH&S department


April 5, 2011

7




April 5, 2011

8


Typical Practice● 6-12 ACH ventilation

● 100% OSA constant volume reheat systems

● 3,000 fpm exhaust at the stack

● 4”-6” pressure on the supply and exhaust fans

● Supply air temperature reset

● Constant volume fume hoods



April 5, 2011

9


VAV Fume Exhaust● Standard off the shelf technologies

● Saves fan energy (supply and exhaust)

● Reduces reheat, heating and cooling

● Improves comfort

● Safer during remodels and retrofits

● Some hoods will remain CV



April 5, 2011

10


Estimated Cost - VAV● Retrofits

– Costs below come from 4 major lab retrofit project. These costs are very conservative.

– Average cost: $22/cfm (VAV and other measures). $/cfm cost decreases as design airflow increases.

● New construction– Case study done by Labs 21: $4.2/cfm


Average of 4 bids~$14.00 for VAV conversion only

Blue dots are total labretrofits


April 5, 2011

11


Estimated Energy Savings - VAV● Simulation results

– Calibrated DOE 2 model based on actual lab at Stanford

– Vary minimum ACH• Decreasing savings as minimum/design airflow ratio increases.



April 5, 2011

12


LCC - VAV

● Simulation results graphical



April 5, 2011

13


LCC - VAV

● Simulation results tabular


6 ACH 14 ACH

Climate Zone City

Incremental cost ($/cfm)

PV of energy cost

savings LCC of VAV

PV of energy cost

savings LCC of VAV

3 Oakland $14.27 -$38.38 -$24.11 -$18.75 -$4.48 6 Torrance $14.27 -$40.55 -$26.28 -$19.95 -$5.68 7 San Diego $14.27 -$37.69 -$23.42 -$19.74 -$5.47 8 Fullerton $14.27 -$38.88 -$24.61 -$22.01 -$7.74 9 Los Angeles $14.27 -$36.46 -$22.19 -$17.77 -$3.50

10 Riverside $14.27 -$40.41 -$26.14 -$20.61 -$6.34 12 Sacramento $14.27 -$43.49 -$29.22 -$21.50 -$7.23 13 Fresno $14.27 -$28.24 -$13.97 -$6.43 $7.84


April 5, 2011

14


Stakeholder Concerns

● Speed of response– See next slide, all systems surveyed used the

ASHRAE 110 test methods

● Feedback on system failure– We’ll add these as a requirements:

• Audible or visible alarm on low face velocity

• Audible or visible alarm on room air balance

● Commissioning

– We’ll add an acceptance test



April 5, 2011

15


Stakeholder Concern: Speed of ResponseASHRAE 1 – Lab Exhaust


April 5, 2011

16




April 5, 2011

17




April 5, 2011

18


Stakeholder Concern: Speed of Response

● From Siemens



April 5, 2011

19


VAV Non-Energy Benefits

● Safety● All valves are pressure independent, remodels in other spaces on a

common supply or exhaust does not impact the operation of other zones (a problem with CV systems).

● Systems measure airflows and report on low hood face velocity and loss of room pressure

● Acoustics● Documented by pre and post measurements by Charles Salter Associates

on Stauffer I and II on the Stanford Campus

● Comfort● Reduction of drafts due to lower airflow (this also increases safety).

● Maintenance● VAV operation reduces wear on motors, belts and bearings



April 5, 2011

20


Next Steps- VAV● Make changes as noted in slides

● Fan power in 144(c) per ASHRAE 90.1

● Add exception to new 144 requirement for VAV allowing constant volume exhaust where required by code, AHJ or the facility EH&S department.



April 5, 2011

21


Estimated Cost, Heat Recovery

● Based on two run-around coils:

– Low Effectiveness ~30%

– High Effeciveness ~50%

● Costs from manufacturer’s quotes


$/cfm Coils (low eff) $0.40 Coil (high eff) $1.01 Pumps $0.12 Piping $0.62 Total (high eff) $1.75 Total (low eff) $1.14


April 5, 2011

22


LCC – Heat RecoveryASHRAE 1 – Lab Exhaust

● 4 climates (3, 8, 9 and 12)

● 2 Efficiencies 30% and 50%

● CV and VAV

● 10ACH and 18 ACH


April 5, 2011

23


LCC – Heat Recovery Base and Reach CodesASHRAE 1 – Lab Exhaust

10 ACH 18 ACH CV VAV CV VAV

Eff = 0.30

Eff = 0.50

Eff = 0.30

Eff = 0.50

Eff = 0.30

Eff = 0.50

Eff = 0.30

Eff = 0.50

CTZ03 $0.81 $4.00 ‐$0.29 $0.28 $0.74 $3.89 $0.01 $0.73 CTZ08 $1.57 $5.01 $0.35 $0.80 $1.04 $4.12 $0.33 $0.82 CTZ09 ‐$0.25 $2.20 ‐$1.00 ‐$1.09 $0.10 $2.65 ‐$0.73 ‐$0.62 CTZ12 ‐$2.95 ‐$1.39 ‐$3.40 ‐$3.95 ‐$2.36 ‐$0.65 ‐$2.49 ‐$2.49

10 ACH 18 ACH CV VAV CV VAV

Eff = 0.30

Eff = 0.50

Eff = 0.30

Eff = 0.50

Eff = 0.30

Eff = 0.50

Eff = 0.30

Eff = 0.50

CTZ03 $1.03 $3.75 $0.16 $0.76 $0.96 $3.66 $0.35 $1.05 CTZ08 $1.55 $4.44 $0.58 $1.07 $1.12 $3.73 $0.54 $1.06 CTZ09 $0.12 $2.23 ‐$0.47 ‐$0.41 $0.40 $2.59 ‐$0.28 ‐$0.07 CTZ12 ‐$1.88 ‐$0.42 ‐$2.24 ‐$2.51 ‐$1.43 $0.15 ‐$1.59 ‐$1.45

Not cost effective

Cost effective for VAV CZ 9& all of CZ 12

Not cost effective

Cost effective for VAV CZ 9& all of CZ 12

Base Code (Part 6) TDVs

Reach Code (Part 11) TDVs


April 5, 2011

24


Energy ResultsASHRAE 1 – Lab Exhaust


April 5, 2011

25


Energy ResultsASHRAE 1 – Lab Exhaust


April 5, 2011

26


Next Steps – Heat Recovery

● Run in more climates

● Consider for reach code



April 5, 2011

27



Documents

Ventilation Topics Stakeholder Meeting 3 - HMGh-m-g.com/T24/.../2-T24_ASHRAE-Vent-StakMtg3_Presentation_4.5.2011.pdfVentilation Topics Stakeholder Meeting 3 Taylor Engineering Energy