The goals that can be achieved by using of BIOSHIELD are: 
- economic saving 
- respect for the environment
These goals are connected: in fact the economic saving correspond to the increase of the thermic efficiency of the condenser and so of the coefficient of heat exchange, that is in inverse proportion to the thickness of the biofilm on the surface of the tubes. The respect of the environment instead, consist in the minimum introduction of chemicals (biocide or other biocides) in order to eliminate the deposit of bacteria on the surface of the tubes.
Today, in order to decide the quantity and length of the treatments, it consider the due experience by comparing the executed procedures with the recorder effects of Biofouling and you make continual or semi-continual injections of biocide.
It is remarkable that only a residual part of biocide carries out its biocidal action, because a fixed percentage reacts instead with the organic substances in the water.
The quantity of these substances can’t be easily estimated, since it depends of many factors (temperature, climate, currents, suspended deposits).
Therefore the procedure of continual injection has the following limits: 

- it effects its biocidal action also when it is not necessary, i.e. when there are not bacteria to eliminate
- for economic and environmental reasons it is necessary to made it in bland concentrations so it is always efficacious.
The procedure of semi continual injection instead:
- effects its biocidal action in statistically” but not “certainly” right moments 
- it is executed in bland concentration and for the same reasons of above.
The use  of BIOSHIELD allows to optimize the duration of the treatments by measuring directly and univocally the thickness of the bacteriological deposit, responsible of the coefficient of heat exchange.
Besides the certainty to avoid any waste of chemicals primes a vicious circle in which one can test and use biocides in a smaller quantity and for less time and these biocides will be always more efficacious and potent (always in the limit of the law).
On the other hand, a good treatment of the devices implies more respect for the environment because treatments that are controlled in quantity and quality diminish the introduction of toxicals in the environment.
The fundamental idea of BIOSHIELD is that to measure the level of bacteria in order to put into action of biocide treatment only at the right moment  and for the necessary time. This principle lead to a strong saving of chemicals because it is well known that the biocide injected to obtain a biocidal effect accomplishes only in part this duty while most of it reacts with the organic substance in the water. Minimizing the length of the injections means to minimize this waste.


Let’s now make a few quantitative consideration by comparing the traditional techniques of injections of biocide (continual and semi-continual) with the one of automatic injections ruled by BIOSHIELD.  
Every hour a Q1 quantity of biocide will be injected; a decimal fraction of Q1  will react with the organic material, in the pipe. So at the entrance of the condenser there will be a quantity of biocide:

 Q2 = Q1 - Q1d1  = Q1 (1-d1 )  
(where Q1
  is the coefficient of the reacting biocide)

This quantity of biocide will effect its biological action inside of the condenser; therefore, on coming out, there will be a quantity of biocide:

Q3 = Q2 - Q2d2  = Q2 (1-d2 ) = Q1 (1-d1 ) (1-d2 )  
d2 is the coefficient inside of the  condenser similar to d1)

Finally, the phenomenon  recurs in the stretch of the pipe going from the condenser to the drainage. So we have:

Q4= Q3 - Q3d3= Q3 (1-d3 )= Q1 (1-d1 ) (1-d2 ) (1-d3 ).

All the coefficient d depend of the characteristics of the system (length, section,  capacity, etc.) and on other variable quantities (temperature of the water and of the ambient, kind of water, etc.).  
Obviously, for environmental and legal reasons, at the drainage it must be valid the condition:

0,2 ppm ³ Q4= Q1 (1-d1 ) (1-d2 ) (1-d3 ).

In the hypothetic semi-continual chlorination we will have a quantity of biocide that is consumed and introduced in the environment.

QTOT =  h Q1 (1-d1 ) (1-d2 ) (1-d3 ).  
(where: h=8,760 in the continual chlorination and h=4,380 in the semi-continual one)

We see how much will be the quantity of biocide used with the automatic chlorination technique controlled by BIOSHIELD.
If we let in the system a quantity of biocide Q’1 exactly like the last case we will have likewise to the previous case a quantity of biocide in the output

Q’4= Q’1 (1-d1 ) (1-d2 ) (1-d3 ).

Look up by the accustomed condition:

0,2 ppm ³ Q’4.

While the total value of the chemical introduction in the environment will be:

Q’TOT =  h’ Q’1 (1-d1 ) (1-d2 ) (1-d3 ).  
(where h is the length of the checked treatment)

All the experiences and the research ( see International Conference of London in 1994) suggest in 10 – 15 days the time necessary in order the thickness of the bacteria layer is like that to obstruct the heat exchanger and in 4 –40 hours the time necessary to destroy that layer.  
We have so that the length of the treatments has a value of:

1.460 ³ h’ ³  98  
that is into the range:

98 Q’1 (1-d1 ) (1-d2 ) (1-d3 ) ³ Q’TOT ³ 1.460 Q’1 (1-d1 ) (1-d2 ) (1-d3 ).

The improvement of the productivity:

m = QTOT / Q’TOT = h / h’

In the hypothesis to use the same concentration of biocide normally used:

Q’1 = Q 1,

meet the following condition:

m = QTOT / Q’TOT = h / h’

like that:

89  ³  m  ³  6

but produce also a possible increase of the quantity of biocide used in the unit of time, thereby if i.e. it should decide to double the concentration of biocide used to obtain a shock effect, we will have at any rate.  
Hypothesizing a cost of installation of BIOSHIELD B = 19,250 USD and 3 real cases of reference in which it consumed biocide for a value of C1
=82,500 USD: one other for a value of C2=165,000 USD and the last for a value of C3=275,000 USD.
So we have a total annual cost installing BIOSHIELD

CBIO  = Cn / m + B  
(where n = 1,2,3)


that compare to the precedent costs gives at the end of the first year of  use a save of

R = Cn - CBIO  
(where n = 1,2,3)

equal in the  3 cases to:

                                            a)     62,150 USD ³ R  ³ 49,500 USD  
143,550 USD ³ R  ³ 118,250 USD  
252,450 USD ³ R  ³ 210,100

Therefore by BIOSHIELD it has the opportunity to make biocide treatments more potent, more efficient, more short and economical with a less environmental impact .