Pharmaceutical industry, it is said jocularly, is obsessed with climate control. This obsession is next only to its deep-rooted love for 'Stain less steel'. Jokes apart, climate control plays a very vital role in ensuring quality drugs am manufacture, distribution and end use.
This vital requirement of drug making is an energy guzzler, hence all aspects of it must be critically viewed, evaluated objectively, designed optimally, last but not the least it must be operated efficiently.
Jones and Jones -- authors of famous machine drawing book in their preface to the book said "Perfection is not a small thing but small things makes perfection".
I am slightly changing the above quote to suit our topic "Cost control is not a small thing but small things make cost control possible". With this approach we shall proceed.
Climate control is nothing but creating requisite climate by
1. Creating air turbulence.
2. Filtering the air to requisite level of cleanliness
3. Addition or deletion of heat and moisture to that air.
Leaving the designated climatic condition requirement for drug making in the realm of chemists, rest of all support groups should concentrate on making the requisite climate at the best of efficiency and least of cost.
A good edifice is built only on sound foundation, in this case, the sound foundation is clarity of our understanding of our climate control requirement this aspect cannot be over emphasized and in adequacy in this aspect is there to be seen in many pharmaceutical units across the country.
Going to a HVAC & R person at the end of all civil activity and expect him to do a good job is like 'Closing the stable doors after the horse is stolen.' The right time to involve HVAC & R person is at blueprint stage
Before interacting with the HVAC & R person, we should have a very clear concept of what, where and how we want the process to flow in the planned facility.
The concept of layout requirement and climate needs of process should be made available to HVAC & R person, who on freezing his design as per user needs will have to have a session with an architect, preferably in the presence of structural engineer. This way an integrated system that compliments each other without any agencies' requirement being trampled by other can be planned and worked out.
The saving potential of this approach is to be seen to be believed!!
Cost of climate control depends on the following:
1. Volume to be brought under climate control.
2. Temperature differential between targeted temperature and ambient condition's high and low value trends.
3. Humidity requirement and ambient condition's highs and lows.
4. Approximate climate conditions within the building.
5. Class of air, air change requirements, density of people and their movement pattern.
6. Heat loads of the area under climate control.
Let us leave the engineering of HVAC & R to professionals and as users, let us know what we should know:
1. Since temperature gradient between requirement and ambient has a role to play, let this also play a role in deciding the location of unit. We can emulate the example set by cotton textile industry that preferred to locate it self in humid areas as humidity has a major role to play in its operations.
2. Let us take temperature and humidity gradients into consideration and decide the layout in such a way that core of building houses the most demanding conditions and periphery houses conditions as nearer to surrounding conditions.
3. Zone classification also should follow the above pattern.
4. To an extent possible drives, heating activity etc. would better be shifted to technical area. A good example of this is the way GMP model Fluid bed dryers, Automatic coating pans that are designed in such a way as to have processing activity part only in the block and rest of the air preparation unit like activities are being located in technical area. This way climate control design need not take their heat load in to consideration.
5. Whenever fresh air is taken in to air conditioning system, use of 'Energy recovery ventilators' generates savings by transferring exhaust air temperature to incoming fresh air.
6. Effective and efficient climate control requires very effective sealing at all places, in the absence of effective sealing climate control system will be over loading itself continuously and consuming more and more power.
7. If indoor air quality suffers due to odour problem, scrubbing devices, which circulate air through activated carbon and molecular sieves, is an efficient method, as neither humidity nor temperature of air being deodorized is disturbed.
8. Building roofs and external walls should be painted with colors that will not absorb heat from surroundings.
In climate control activity, we should ensure effective heat transfer when and where required and equally effective and efficient heat insulation / isolation as required.
Effective sealing is necessary for achieving and maintaining target climate conditions at minimum operating costs.
Leak proof concept should be built into system at lay out stage itself by proper design of doors, view panels, false ceiling, peripheral walls and what all can cause heat loss through all the three modes of heat transfer (i.e.)
1. Conduction
2. Convection
3. Radiation
On taking care of the above let us look at what effect a poorly maintained climate control system with specific reference to low side will have on operating costs and system in efficiencies.
Ducting needs to be cleaned periodically, as the dust particles that settle in ducts tend to block filters, cause cross contamination of product and corrosion. Corroded ducts tend to develop leaks and add to climate control load. Filters that are not maintained properly either block the flow of air or allow dust-laden air to pass, which will block the coil in no time. Blocked coil will effect heat transfer, block airflow, disturb room pressure balancing and all other ills that follow an imbalanced pressure gradients.
Insulation of cooling media lines, air ducts, condensate drains must be maintained in top condition.
Condensate would better be put to use in services like scrubber that way plant water requirement also can be reduced.
Clogged condensate drain allows water to accumulate in `cooling coil condensate collection tray'; accumulated water in this tray goes in to air stream again and plays havoc with dehumidification values.
Heat recovery units for descant type de humidifiers reduces power requirement for heaters used for heating regeneration air.
Within the building, temperature and humidity zones should be arranged to form a natural curve pattern and adjacent areas of steep rise or fall are to be avoided to possible extent.
Lighting contributes to increased climate control cost, lighting design should be only up to requisite flux level and over illumination should be avoided energy saving and climate control load reduction, Excess lighting should be avoided and we should choose low heat emitting lighting systems and incandescent lamps must be avoided to the extent possible.
All areas proposed to be under climate control to be sized to strike a balance between space requirement and cost of installing and maintaining climate control system, this space requirement balancing gives lot of savings in climate control capitol and revenue expenditure.
All doors in climate control area would better be of off set type this way small door will be operating door for men movement and big door will be used for material movement when required. This arrangement reduces door operation losses in air conditioning system.
Adopting a discipline of rationalized movement of men and material consciously reducing door operations will help efficient climate control system maintenance.
Condition and accuracy of temperature / humidity sensors and controls should be under close watch. In case of any malfunctioning we will be draining money unnecessarily without being unaware.
Next comes the simple looking dampers, these largely over looked critical component of climate control, when not given its due regard, it simply stops controlling. The uncontrolled air movement goes on consuming power and ensures that our climate control is not doing its job. All dampers at all times should be able to stop or allow air passage as per requirement.
Providing V.F.D. is energy efficient alternate for damper control, we should incorporate them wherever possible in lieu of damper control.
Air classification requirement is largely dictated by product needs.
Parenterals and liquid orals tops the list best class of air demanders and they are closely followed by ACTIVES sampling and dispensing areas.
Oral Solid Dosage forms manufacturing areas trail the above two some for air classification requirements.
Air classification adds to the cost by increase in fan capacities, drive requirements, cost of superior grade filters, their maintenance and replacement cost. Here also we should exercise due caution to ensure only requisite classification level appropriate for the activity in that area is targeted for and maintained.
Higher-class level in areas that do not warrant for it is a drain on precious energy and resultant costs.
When a system is designed with low safety margins, role of maintenance becomes very vital.
Maintenance should carry out set preventive maintenance functions religiously and see to it that system is in ship shape always and functions at peak of efficiency at any given time during its life.
Frequent changes and ad-hoc arrangements in climate control system will go against optimization approach hence it is always better that one goes for well thought over requirement freezing, because all our efficiency efforts go waste if our basic thinking is not on well thought over plan.
Modern automated building management system aims to achieve all this and much more but even the best of systems cannot deliver goods if what all we discussed above are not looked in to.
To conclude we have all the technology available at our doorsteps what is required is our understanding of it and adopting to suit our needs.
Efficiencies achieved in climate control are essential for not only cost control but also for ensuring conservation of precious and fast depleting energy resources of world.
-- The author is Sr Manager (Engg.), Sidmak Laboratories (India) Pvt Ltd, Valsad