Thermal Cleaning and Air Pollution Control with Heat Recovery for HVAC Equipment Supplier
Executive Summary
Epcon designed and supplied a custom integrated system for a major HVAC-equipment supplier — combining a thermal-cleaning oven (for oil-residue removal from HVAC coils) with a recuperative thermal oxidizer (RTO) featuring primary and secondary heat-recovery syetem. This solution eliminated the need for a separate burner in the oven (“burner-less” oven design), destroyed solvents and emissions from the cleaning process, and re-used waste heat — resulting in substantial energy savings (~ 5.5 MMBtu/hr), improved environmental compliance, and a payback period of less than five years.
Project Overview
The customer — an HVAC equipment manufacturer supplying coils — required a process to thermally clean residual oil from newly manufactured HVAC coils. The cleaning process volatilized oils/solvents, generating exhaust containing volatile organic compounds (VOCs) that required abatement. Instead of using a traditional separate oven plus exhaust control, the customer sought a fully integrated “oven + oxidizer + heat-recovery” solution, to reduce energy consumption, eliminate emissions issues, and improve process efficiency.
Epcon was contracted to engineer a complete system: a dual-lane conveyor oven for coil cleaning, coupled with a recuperative thermal oxidizer with both primary and secondary heat-recovery — effectively using oxidizer exhaust heat to power the oven, minimizing or eliminating additional fuel demand.
The Challenge
Key challenges to address:
- Residual oil on HVAC coils — manufacturing process left oil residues that must be removed to avoid product contamination or failure in service. The cleaning required thermal processing that volatilizes oils/solvents.
- Air emissions from solvent evaporation — the cleaning generates solvent-laden exhaust; regulatory and environmental compliance demands VOC / HAP abatement rather than simple venting. Thermal oxidizers are a standard, proven method to destroy VOCs and organics in exhaust streams.
- Energy inefficiency of conventional ovens with separate VOC abatement — using a standalone oven plus separate oxidizer leads to duplicated fuel/energy demand. Heating the oven and separately combusting exhaust is fuel-intensive and costly.
Need for a turnkey, integrated solution — to minimize capital and operating cost, simplify operation, and avoid the complexity of managing separate oven and pollution-control systems.
The Solution
Epcon delivered an integrated Oven–Oxidizer–Heat-Recovery System, featuring:
- Dual-lane conveyor oven equipped with precision lane-adjustment and specially arranged air-distribution nozzles to deliver controlled hot-air impingement over HVAC coils — ensuring uniform oil-residue removal with high throughput.
- Recuperative thermal oxidizer (RTO) with primary and secondary heat-recovery: exhaust from the oxidizer is used to preheat incoming air and, in addition, to heat ambient air (from ~ 70 °F up to ~ 650 °F), which is then fed into the oven heating chamber — enabling a “burner-less” oven mode (or minimal burner use) because waste heat powers the cleaning oven.
- Fully integrated design — combining thermal cleaning, VOC abatement, and heat reuse — reducing operational complexity, improving energy efficiency, and ensuring emissions compliance.
By using the oxidizer’s heat output to run the oven, the solution transforms a normally high-energy, high-emissions cleaning line into a cost-efficient, environmentally responsible process.
Technical Specifications
Oven Type: Dual-lane conveyor thermal-cleaning oven for HVAC coils — designed for removal of oil residues via hot-air wash/evaporation under controlled conditions.
Oven Heating Method: Recuperative-oxidizer-driven hot-air supply (secondary heat exchanger heating ambient air to ~ 650 °F) — enabling “burner-less” operation or significant reduction of auxiliary fuel demand.
Airflow / Air-distribution: Precision nozzle arrangement enabling high- and low-pressure air-impingement over specific areas of coils — ensuring uniform, efficient solvent evaporation and cleaning.
Pollution Control Device: Recuperative thermal oxidizer (RTO) — for destruction of solvents / VOCs emitted during the cleaning process, converting pollutants to CO₂ and H₂O.
Heat Recovery Configuration: Primary heat exchanger: preheat oxidizer airflow; Secondary (economizer): heat ambient air for oven, maximizing energy recovery.
Energy Savings / Performance Outcome: ~ 5.5 MMBtu/hour energy savings compared to conventional system — leading to annual savings of approx. USD 125,000 and payback period under 5 years.
System Integration: Turnkey solution: oven + oxidizer + heat-recovery + controls + installation + commissioning — delivered by Epcon as a full package.
The Results
After commissioning, the integrated system delivered the following key benefits:
- Major energy savings → lower operating costs: The heat-recovery approach saved approximately 5.5 MMBtu/hr, representing annual fuel/energy savings around USD 125,000.
- Faster payoff / high ROI: With those savings, the customer recovered the system investment in under five years — a faster return than typical for industrial ovens + abatement equipment.
- Improved environmental compliance & VOC abatement: The recuperative oxidizer ensures solvents/VOCs released during cleaning are destroyed rather than emitted — reducing emissions, odors, and potential regulatory risk. This aligns with the standard use of thermal oxidizers for VOC and HAP control.
- Simplified, integrated operation: With the oven and air-pollution control system combined into one integrated system, workflow is streamlined — less equipment, fewer subsystems to manage, lower maintenance overhead, and easier operator control.
- Increased production capacity while staying compliant: According to the customer, after installation they increased throughput by ~ 15% while still meeting stricter emissions limits.
Sustainable operational model: Using waste heat for cleaning reduces overall fuel consumption and emissions — supporting corporate sustainability and environmental responsibility goals, which is increasingly important for industrial manufacturers.
