This is a composite case based on real patterns Enerlogix has handled with food-and-beverage plants in the Bajío region. Some operational details have been modified to preserve confidentiality, but the measures, the numbers, and the lessons reflect real executions.
When the plant manager asked for "only the measures that pay for themselves in under a year," the project changed in nature: it stopped being an ambitious three-year efficiency plan and became a short list of five HVAC quick wins with an ROI under 12 months. None required halting production or a lengthy investment committee. This case shows exactly which ones they were and why they work.
The context
A processed-foods plant in the Bajío, with 2.8 MW of contracted demand, runs process lines with thermal requirements (cooking, cooling, product refrigeration) and a large HVAC system for climate control of bays and process areas. Annual electricity spend of approximately MX$16 million, where HVAC and refrigeration accounted for nearly 45%.
Management had rejected previous efficiency projects because of their long paybacks (3-5 years) and because they demanded production stoppages. The directive was explicit: low-risk measures, no shutdowns, with returns under 12 months. The energy audit was designed with that filter.
The 5 measures with an ROI under 12 months
From an initial list of 14 opportunities, only five passed the filter of payback under 12 months and zero production downtime. Those were executed first.
1 · Variable frequency drives on pumps and fans · payback ~7 months
The chilled-water pumps and the air-handler fans operated at constant speed. Installing variable frequency drives to modulate according to real load is the highest-return measure in almost any HVAC system: a fan's consumption falls with the cube of its speed, so a moderate reduction in flow produces a large saving.
2 · Free cooling (economizer) · payback ~9 months
The Bajío has many hours a year with cool outside air. Enabling economizers that use outside air for cooling when conditions allow, instead of running the chillers, cut compressor hours with no investment in new cooling equipment.
3 · Setpoint adjustment and zoning · immediate payback
Areas that did not require the same temperature were being climate-controlled identically. Zoning the control and adjusting setpoints to the real requirement of each area —without affecting food safety or comfort— was practically free and began saving from day one.
4 · Condenser cleaning and heat recovery · payback ~5 months
Dirty condensers force the compressor to work harder. A cleaning program plus recovering condensation heat to preheat process water lowered both chiller consumption and heating consumption, attacking two costs with a single measure.
5 · Peak demand management · payback ~4 months
The simultaneous startup of refrigeration and climate-control equipment created peak demand spikes that inflated the fixed charge on the bill. A controller that staggers startups flattened those spikes with no investment in major hardware.
Results at 12 months
| Measure | Investment (MXN) | Annual saving (MXN) | Payback |
|---|---|---|---|
| Variable frequency drives on pumps and fans | ~$680,000 | ~$1,150,000 | ~7 months |
| Free cooling | ~$420,000 | ~$560,000 | ~9 months |
| Setpoints and zoning | ~$60,000 | ~$340,000 | immediate |
| Condenser cleaning and heat recovery | ~$240,000 | ~$580,000 | ~5 months |
| Peak demand management | ~$180,000 | ~$520,000 | ~4 months |
| Total | ~$1,580,000 | ~$3,150,000 | ~6 months average |
The plant's total electricity consumption fell by nearly 14% and annual electricity cost went from around $16 million to around MX$13.6 million, without a single production stoppage.
Lessons from the case
1. The short-payback filter unlocks projects
The same HVAC system that had projects rejected for 3-5 year paybacks contained five measures with returns under 12 months. Separating the quick wins from the ambitious plan made it possible to approve and execute the most profitable items immediately. It is the logic of efficiency measures ranked by ROI.
2. The quick wins finance the big plan
The ~$3.15 million in annual savings generated cash to later tackle the longer-payback measures (larger heat recovery, chiller replacement) with their own money, without fighting for new budget.
3. Variable frequency drives and free cooling are almost always profitable
In HVAC systems running at constant speed or without an economizer, these two measures appear again and again as the best-return options. If a plant doesn't have them, there is almost certainly savings there.
4. Without measurement, there is no prioritization
The "payback under 12 months" filter is only possible if you measure first. Without the audit that quantified each opportunity, the plant would have kept rejecting the entire package over its average payback, ignoring that five measures were excellent.
Is your plant in a similar situation?
If your plant has a large HVAC or refrigeration system, you have rejected efficiency projects over long paybacks, and you can't afford production stoppages, you probably have hidden quick wins like the ones in this case. The key is to measure and filter by return, not to evaluate the whole package as a single block.
At Enerlogix we execute Plan 360 Management always prioritizing by ROI: first what pays for itself, then the ambitious work financed with the savings. Every case is different, but the pattern repeats.
Request a free evaluation or learn about our energy optimization service. For the complete framework, read the practical guide to energy optimization and energy efficiency as a business strategy. And if your HVAC runs 24/7 under critical conditions, review the HVAC case in electronics with cleanrooms.
Frequently asked questions
The five that appear again and again with returns under 12 months are: variable frequency drives on pumps and fans, free cooling or economizers that use outside air, setpoint adjustment with zoning, condenser cleaning and heat recovery, and peak demand management by staggering startups. In this case the average payback of the package was nearly 6 months, with a total investment of around 1,580,000 MXN.
Because a fan's or pump's consumption falls roughly with the cube of its speed. That means a moderate reduction in flow, adjusted to the real load instead of running at constant speed, produces a disproportionately large saving. In systems that currently run at fixed speed, variable frequency drives are usually the highest-return measure, with typical paybacks of several months.
Yes. In this case the five measures were executed without a single production stoppage, because they were chosen precisely with that filter: low risk, no shutdowns, and payback under 12 months. Installing the drives, enabling free cooling, zoning, cleaning the condensers, and staggering startups were all done during normal operation or in existing maintenance windows.
In this case the plant's total electricity consumption fell by nearly 14% and the annual cost went from around 16 million to around 13.6 million pesos, with the five short-payback measures alone. The real percentage depends on the current state of the system, on whether it already has drives and economizers, and on HVAC's share of total consumption, which in food and beverage usually runs around 45%.
Because evaluating the whole package as a single block leads to rejecting it over its average payback, ignoring that some measures are excellent. Separating those with returns under 12 months lets you approve and execute them immediately, and the savings they generate then finance the longer-payback measures with your own money, without fighting for new budget. This is only possible if you measure and quantify each opportunity first.
