Heat Recovery Unit (HRU)
A heat recovery unit (HRU) can make mechanical ventilation more cost effective by reclaiming energy from exhaust airflows. HRU use air-to-air heat exchangers to heat incoming fresh air, recovering 40 to 85 percent of the temperature and/or that would otherwise be lost. Savings:
HRU can reduce 40% of fuel cost in stenter, without any compromise.
Payback period of 2 years.
- Exhaust gas from the system is redirected from chimney to HRU. for heat recovery.
- The exhaust gas passes through tubes in one direction, while the fresh air is passes by fins in counter direction.
- Due to close contact of exhaust air and fresh air, heat transfer takes place.
- The recovered heat is passed in to the system (dryer) and exhaust air is reconnected to chimney.
- Flow is managed by two fans and controlled by damper.
- Exhaust air inlet temperature to HRU 120 – 200 °C (depending on the process)
- Exhaust air outlet temperature from HRU 70 - 100 °C
- Ambient air inlet temperature to HRU 30°C - 35°C
- Ambient air outlet temperature to HRU 130 - 140°C
- Two layers of 25mm thick Insulation is provided all over the unit, to avoid the loss of heat when the system is in operation.
- Can be easily fitted into existing exhaust duct, which eliminates the expensive re-ducting.
- Completely pre-assembled and ready for installation.
- Simple design, Easy and low maintenance cost, Cost efficient
- HRU is suitable for commercial usage and mostly used in textile industry for stenter and dryer.
- It can also be used for different application, where exhaust heat is between 120°C to 230°C.