How to reduce energy consumption in pharma environment trough HVAC optimization

Case study :

Dead Band Control of Relative HumidityLuc Willem, 17/06/2009

GSK Bio Objectives

Reduce operational Global Warming Potential (GWP) and energy consumption per unit sales from 2006 baseline

Reduce 20%

2010

Reduce 45%

20151334GJ/£million

1253 -6.1%Q4 2008

2006

1067

734

GSK Bio Energy Consumption

All Bio Sites :

2008 GSKBio Consumption : 812,158 MWh

41,000,000 € spent

Energy Cost Breakdown in Pharma Industry

Energy cost breakdown - pharma

humidification / de-humidification, 8%

ventilation, 30%

process, 6%lighting, 15%compressed air, 4%

pumps, 6%

cooling, 26%

hot water, 3%

miscellaneous , 2%

HVAC ~ 65 % of total energy consumption !

HVAC = best candidate for energy saving projects

Project : Dead Band Control of Relative Humidity

Scope : extend the control interval for relative humidity in clean rooms

Grade D, C, B + unclassified

Today, the window is non existent : saving will beimmense

Yes, but what are the GMP requirements for sterileproducts facilities ?

Regulatory – Guidances

No formal GMP requirements in EU GMP (annex 1) or in FDA APG 2004 :

Only recommended limits for microbial contamination

Rule of thumb for the relative humidity in aseptic cleanroom :

> 30% to control static electricity < 60% to control rust, organism growth and personal from sweating

GSKBIO revised global specifications (unless local laws)- 30 – 60 % RH for grade C / D (before setpoint = 50%)- 30 – 50 % RH for grade A / B (before setpoint = 40%)- 30 – 65 % RH for non-classified areas

Typical GSKBio HVAC configuration

RH sensor

Cooling coils Post heating Steam humidifier

Before – 1/2

Current Situation : same value of RH setpoint for the PID controls of humidifier and cooling coils

Humidifier valve

Cooling coilvalve

RH

Fixed setpoint

50 % for grade D/C

(example)

Before – 2/2

40% RH constant

% humidifier

% coolingvalve

Proposed Modification

Proposal : differentiate RH setpoints for humidifer and cooling coil, but still within the accepted limits

Dead band Less chilled / glycol water consumption in summer (de-humidification)

Reduced post heating need

Less steamconsumption in winter for humidification

Setpoint for cooling coil

58%

Setpoint for humidifier 35 %RH

(example)

Belgium Climate Case Study

Thermodynamical simulations using monthly averageclimate data (done internally) :

10,000 m3/H air handling systemGrade C or DChilled water 7 – 12°CHumidification with black steam 3 barg

50% RH (fixed) 40 – 58 % RH (dead-band)NB : 40% RH min = RGPT (social law)

2 cases :Mixing system (20% fresh air)100 % Outside Air

Results of Simulation

Ex : 20% fresh air system

Fixed setpoint (50% RH)

0

5

10

15

20

25

30

35

40

Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov

KW

SteamCoolingPost Heating

Dead Band 40 - 58 %RH

0

5

10

15

20

25

30

35

40

Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct NovK

W

SteamCoolingPost Heating

Expected Gains – Belgium Climate

Changing RH levels at fixed 20°C , 10.000 m3/H, grade C/D, 20% fresh air

010 00020 00030 00040 00050 00060 00070 00080 00090 000

100 000110 000120 000

RHH = 50 RHL = 50 RHH = 58 RHL = 40

kwH

/ ye

ar Re-heatingCooling and de-humidificationHumidification black steam

NB : kwH cooling and kwH humidification = thermal demand (do not include Chiller COP and boiler efficiency)

Expected Gains – Belgium Climate

Changing RH level at fixed °C, 10.000 m3/H, grade C/D, 100% fresh air

010 00020 00030 00040 00050 00060 00070 00080 00090 000

100 000110 000

RHH = 50 RHL = 50 RHH = 58 RHL = 40

kwH

per

yea

r

Re-heatingCooling and de-humidificationHumidification black steam

NB : kwH cooling and kwH humidification = thermal demand (do not include Chiller COP and boiler efficiency)

Expected Gains – Belgium Climate

Benefit for 10.000 m3/H, grade C/D, 20% fresh air :

3600 € / year (~ 22 € / m2 / year)

Benefit for 10.000 m3/H, grade C/D, 100% fresh air :

5500 € / year (~ 34 € / m2 / year)

Expected Gains – Belgium ClimateWavre + Rixensart + Gemboux :

~ 32.000 m2 of grade C/D area

32.000 x 22 € / m2 / year :

~ 704.000 € / year benefit for all BelgiumSites

=

~ 2 % of overall Bio energy consumption

Investment Cost

BMS modification :If setpoints are distincts and available at administrator levellevel 0 € !If setpoints are no available at supervision level, software modification is needed 1200 €

Validation cost :Rooms to be re-validated in temperature and RH4 hours T / RH monitoring with portable probe = 110 €/room

Payback – Belgium Climate

One AHU of 50.000 m3/H grade C with 6 rooms, PX + Desigo, 20% fresh air :

- 1200 € for modification of BMS by Siemens

- 6 x 110 € for T/RH re-qualification = 660 €

- 140 € contingencies

- TOTAL investment : 2000 €

- benefit : 18000 €/year

PAYBACK = 1 month !

Other GSK Bio Sites

Greater benefits are expected in our facilties whereclimate is more adverse than in Belgium !

Singapore (only de-humidification) Climate data :

Average mean temp : 27,5°CAverage dewpoint : 24°C = 18,8 gr/Kg !!

Example of Make-up AHU, grade C/D, 100% O.A., 10.000 m3/HIf setpoint of cooling coil = 9,2°C = 7,25 gr/kg (= 20°C/50%)

Chilled water consumption : 154 kWPost heating need : 19 kW (heat loads excluded)

If setpoint of cooling coil = 11,5 °C = 8,42 gr/Kg (= 20°C/58%)Chilled water consumption : 120 kWPost-heating need : 14 kW

SAVING = 272.000 kWH chilled water + 40.000 kWH steam per year for 10.000 m3/H of fresh air (MAHU)

Dresden (mainly humidification)Climate data :

Average dewpoint always < 7.6 gr/kg humidification mainly

Dresden = mainly 100% O.A. systems with SEW recovery

Example of fresh air system, grade C/D, 100% O.A., 10.000 m3/H :

If the humidifier setpoint is fixed at 40%RH instead of 50 %RH (at20°C), i.e. 5,78 instead of 7,25 gr/kg, the expected saving is 122 tons of steam per year for 10.000 m3/H of fresf air

Conclusions

Quick Win modification !

Extrapolation to all GSK Bio Sites = saving of 3-4 % of overall energy cost (1,5 M€ saving per year)

Pharma industry very conservative group need to convince QA and Validation

Modification of acceptance criteria in validation file may be hard sometimes …

Remark : GSKBio BMS is not validated; this helpsmaking such control system modification