Spray Booth Energy Efficency

Are you looking to buy a new spray booth or a heater?  Are you concerned about how much it will cost to operate?   Are you confused about various claims of energy savings?  We can help you with making this difficult decision.

Buying the right spray booth heating system is an important long term investment.  You will operate this equipment for 20-25 years.  The cost of the heating system should not be your main concern.  The cost of operation for the life time should be the reason to buy a spray booth heating system.  Over the life time of the equipment the right spray booth heating system can save you enough money to pay for itself several times! 

We developed a simple, three step process to help you decide which spray booth control system is right for you:

1. We will explain available technologies that can reduce the operating cost of your spray booth. 

2. We will help you to understand how much these technologies actually save in your circumstances.  We can give you energy calculations for your specific climate and operating conditions.  We do not charge for this service.

3. You can make a decision on which technologies provide the best return on your investment.

Factors That Affect Energy Usage of Spray Booths 

We identified the following factors that affect spray booth energy consumption:

1. Local Climate

The colder it is in your geographic area the more heat you will need.  We don’t have any control over this factor.

2.  Availability of turbulent air flow

Turbulent air flow is very important for spray booths.  Turbulence decreases the length of time it takes to dry waterborne coating.  Turbulence also enhances the convection process.  Turbulence helps the heat transfer between spray booth cabin air and the panel temperature.  It is a well proven fact that Bake times can be reduced if a turbulence creation device (waterborne paint drying system) operates during the Bake Mode.

3.  Heat Loss

No insulation or poor insulation will effect of energy usage.

4. Operator behavior

It is imperative to educate the painter on the importance of turning airflow on only when it is needed.   There is little that can be done to engineer the human factor out.  The painter has to be trained in the correct operation of the spray booth.

5.  Paint Product Used

Paint products affect energy efficiency in two ways:

A.  The length of required curing time.

Clearly a product that has a shorter drying or curing time will use less energy.

B. The required curing temperature.  

A product that requires a lower curing temperature will use less energy.

6.  The air flow rate within the system

You have to reduce the air flow rate inside the booth.  For example, if the painter is not spraying, air flow should slow down.  There is no reason to move more air than it is necessary.  A lower air flow rate requires less electrical energy to move. 

7.  Exhaust Air flow Rate

This is the most important area.  Large energy savings can be realized by carefully controlling spray booth exhaust rate.  The goal is to reduce the flow rate of heated air that leaves the booth. 

                                                          Examples of The Savings

We made two sets of calculations to show how much various technologies actually save. The first set of calculations are for a standard automotive booth with a 12,000cfm ventilation rate. The second set of calculations are for a truck booth that ventilates at 25,000cfm.

We calculated the savings at 4, 6, and 8 spray booth cycles per day. We used the climate data of Kansas City, KS because this represents the US average. We assumed two coats per cycle, a Flash-Off Mode to dry the waterborne base coat and a Bake Mode to bake the clear coat on.  The tables represent the typical vehicle refinishing cycle.

The results of yearly and life time energy usage is the best illustration of varying operating costs and savings.  Since outdoor temperature varies month to month, one has to consider a full year to get an accurate estimate of operating costs. Since spray booths and heating systems are used for at least 20 years, we used a 20 year life cycle to calculate the total savings.

We made five columns for five different control technologies.  You can see how much each control technology actually saves. 

The table answers many questions.  For example, should you buy a spray booth with an 80/20 recirculation system?  Is it a good investment to spend the extra money?

At 6 cars per day, the recirculation system will pay for itself in less than 2 years.  Over the life cycle of the equipment, the 80/20 recirculation system will save almost $110,000!  I consider this an excellent investment.

It is also interesting to consider the cost of a spray booth and the life cycle savings of energy efficient control technologies.  Energy efficient spray booths can pay for themselves at least 2-3 times during their life cycle!

The truck booth table above shows that as the booth size increases, savings increase also.  At 6 cycles per day, this truck booth will save almost $400,000 over its life cycle.

Spray booth ovens use a substantial amount of energy to operate.  Buying hte right control system will save you thousands of dollars over the life time of the equipment.