Energy cost reduction for HVAC on a production floor

If the ambient air is above the average outside air temperature (not just in the summer), then it would save energy to use 100% outside air.

One nice thing about that is that the cooled air supply can be directed at operators' spaces, much like "spot coolers."

Hi Noshort,

First nice to hear that you have concerned on company regarding energy conservation. However, for 3 years now they don't bother and listen on you. I would say due to lack of proper presentation, support and justification where ROI is one of the great issue during the presentation/discussion stage.

As your question: "how to calculate the ROI"? my simple idea is.

Target Savings in terms of $$$$$ - cost of investment = ROI.

Taking into accounts, the objective mustn't adversely affect the operation and or sacrificing the health condition of the staff as maybe the management also thinking staff working environment as they also includes on thier computation how much it cost for future staff hospitalization? but i would say your idea is very great! keep on trying. if you can save 30% on energy cost or maybe more, don't give up. This is my 4th year now of waiting for my Building Energy Management computerization system, which is budgeted approved however lack of funding then maybe we have the same problem, for sure the management did not forget or ignore your proposal however it could be lack of actual funding.

Also good luck!!!!

Kind regards

Roman

"I would say due to lack of proper presentation"

That was what I eventually figured out when back I did projects. I tried telling them (management/accounting) what made sense to me, but it was like I was talking to my sisters children. Through careful listening and observing I figured out "what they wanted to hear" and geared my presentations toward that, explaining to the contractors, consultants and vendors that when the conference room door closed , I was representing their product or idea....not them. I turned into a salesman during the meetings and learned how to get things done. CAUTION!...do not lie...you loose all trust and credibility..there are many buzz words/ phrases at your disposal but only use the ones they want to hear.

This is all assuming that it's a legit project that should be done in the first place.

Your idea is a good one. However, management will only be intereted if you present to them in such a way that they will improve thier bottomline. Present a positive ROI is the way to go. It's not that difficult to do, however, we need more information. That's the difficult part. You need to do some homework. Here's what you need:

What it would cost to run the new equipment (monthly) - The cost to run the current equipment (Monthly) = Net monthly savings.

Then, get your total cost of the new equipment installed and divide that by the Net MonthlySavings = Your Breakeven Point (BEP) in months.

Then you can determine your ROI by taking 12 months divided by your BEP = ROI%

Example: Let's say the existing equipment costs $2400 per month to run and the new equipment will cost $1400 per month to run. That means your Net Monthly savings is $1,000 per month.

We'll estimate the cost of the new equipment at $36,000 divided by your Net Monthly Savings of $1,000 per month = a 36 month BEP.

Then take 12 months divided by your BEP of 36 months = An ROI of 33.3%

Then take that to management and ask them where they can invest their money anywhere today and get that kind of Return on Investment?

They'll be alot more interested in hearing what you have to say.

1. Calculate the total heat load

2. Get a firm figure on an induction hood TOTAL installed cost. This brings in fresh air in front of the apparatus and pulls exhaust from the rear. This has 2 benefits: you will only remove about 5% of the conditioned building air, while exhausting the hot air and (2) it creates an air curtain effect.

3. Estimate the a/c energy used to bring the heat load down to building ambient.

4. Add together the #2 cost plus the energy to run it.

5. Subtract this from #3. This is your ROI (less the 5% of course).

We do this type of work on a regular basis and successfully sell the total package based on ROI.

There are hoods installed lineraly over the extruder barrells. The problem is that the same hood brings in fresh outside air and exhausts the heat with no division of space.

Noshorts,

As Peteciliberto has said, run the numbers to see if your ideas are sellable. Many companies will not look at any capital expenditures if the ROI is any less than 33% (or some other number close to this).

It is also possible that your approach is trying to answer the wrong question(s).

• In the commercial kitchen industry as well as in fireplace technology, the best energy savings with air exhaust problems are to bring in fresh air without conditioning it, directly from the outside, to replace 100% of the air being exhausted. This is done in such a way that the air intake is minimally mixed with the building's ambient air. Thus, the cost of conditioning the ambient air is minimized because the makeup process air is separated from it. I'm not sure if your description of the company's current process is what I have described above.
• Have you looked at reducing the heat loss from the process equipment? Better insulation of this equipment may be possible, leading to a reduced operating cost per unit produced. The side benefit is decreased need for conditioning the ambient air and increased worker comfort and safety. Poor insulation is often a result of aging, wear & tear, maintenance practices, and equipment design obsolescence.
• What about the cooling of the product itself? You indicate that it is a source of heat within the factory. Can fan-directed air flow be designed to exhaust some of this waste heat in a way similar to that for the equipment?
• Is it possible to use any of the "waste" heat via heat exchange or heat recovery systems, to supply a portion of the heating energy needs of the plant? This is a change in perspective--instead of seeing the heat as a waste product to be thrown away it is seen as a resource to be utilized or sold.

Let us know your opinions on these things. --JMM

Not knowing your process, is there something else that you can do with this waste 400 degree energy instead of blowing it into the atmosphere? Check out www.sidelsystems.com

Can you utilize the hot exhaust to generate power ?

if you want a solution you can contact pawan@mechartes.com +919811408957 this an IIT based engineering services company they will solve the problem by using CFD .

gagan

Noshorts

Here's an outside the box idea to chew on. Check out heat pipe technology, understand how it works and see if you can make it work to syphon the heat off your presses. No moving parts, lot cheaper to operate, quick payback. I use these as cabinet coolers(Noren) in my very dusty environment, no problems since installation.