1. Temperature regulation: In winter, the heat exchanger can recover the heat from the humid and hot air discharged from the greenhouse, preheat the cold air entering the greenhouse, reduce heating energy consumption, maintain stable indoor temperature, and promote crop growth. In summer, it can utilize cool nighttime air or low-temperature resources such as groundwater to cool the air entering the greenhouse through a heat exchanger, reducing indoor temperature and avoiding high temperature hazards to crops.
2. Humidity control: In some greenhouses with high humidity, heat exchange can be carried out through heat exchangers to remove moisture from the air during the cooling process, achieving the purpose of dehumidification, creating a suitable humidity environment for crops, and reducing the occurrence of pests and diseases.
The role of heat exchangers in agricultural ventilation
Energy conservation and consumption reduction: In agricultural facilities such as greenhouses and breeding farms, heat exchangers can utilize the energy of exhaust air to pretreat fresh air. For example, in winter, transferring the heat from the exhaust to the incoming cold air can increase the temperature of the fresh air and reduce heating energy consumption; In summer, the cooling capacity of exhaust can be used to cool the fresh air and reduce the cooling load of air conditioning.
Improving the environment: By using heat exchangers for heat exchange, the temperature of the air entering agricultural facilities can be brought closer to the indoor ambient temperature, reducing temperature fluctuations caused by ventilation and providing a more stable and suitable environment for crop growth or animal husbandry. At the same time, some heat exchangers can achieve complete isolation between fresh air and exhaust air, avoid cross contamination, and ensure the cleanliness of fresh air, which is particularly important for agricultural production with high environmental requirements such as aseptic cultivation and SPF level animal breeding.
Common types of heat exchangers in agricultural ventilation
Plate heat exchanger: Its advantages are compact structure, high heat transfer efficiency, small footprint, and easy disassembly, cleaning, and maintenance. A ventilation system suitable for various agricultural facilities such as greenhouses and breeding farms, which can achieve efficient sensible heat exchange.
Heat pipe heat exchanger: With the heat pipe as the core heat exchange element, it utilizes the phase change heat transfer of the working fluid inside the pipe to achieve heat transfer. Heat pipe heat exchangers have the advantages of high heat transfer efficiency, good isothermal properties, and the ability to achieve long-distance heat transfer. In the agricultural field, especially in places with strict requirements for environmental temperature and humidity control, such as animal rooms and laboratories, heat pipe heat exchangers can effectively recover waste heat while avoiding cross contamination and adapting to a wide temperature range environment.
Shell and tube heat exchanger: composed of shell, tube bundle, tube plate and other components, the fluid flows in the tube and shell sides for heat exchange. The shell and tube heat exchanger has a sturdy structure and can withstand high pressure and temperature, making it suitable for large-scale agricultural facilities that require high stability and reliability of ventilation systems, such as large greenhouse clusters or large-scale breeding farms. By installing fins on the tube, its heat transfer efficiency can be further improved and its applicability in agricultural ventilation can be enhanced.
What is air to air heat recovery unit?
An air-to-air heat recovery unit is a device that transfers heat (and sometimes moisture) between two separate air streams—typically incoming fresh air and outgoing exhaust air—without mixing them. It improves energy efficiency by recovering heat from the exhaust air to precondition the incoming air, reducing the energy needed for heating or cooling in HVAC systems or industrial processes.
Key Features:
- Operation: Uses a heat exchanger (e.g., counterflow, cross-flow, or rotary) to transfer heat. In counterflow units, air streams flow in opposite directions for maximum efficiency (70-90%).
- Types:
- Plate Heat Exchangers: Fixed plates separate air streams, transferring sensible heat (temperature only).
- Rotary Heat Exchangers: Rotating wheels transfer both sensible and latent heat (moisture).
- Heat Pipes: Use phase-change technology for efficient heat transfer.
- Applications: Ventilation systems in buildings, industrial processes, data centers, and energy recovery systems.
- Benefits: Lowers energy costs, reduces carbon footprint, and maintains indoor air quality by preventing cross-contamination.
- Example: In winter, a unit might transfer heat from warm exhaust air (e.g., 20°C) to cold incoming air (e.g., 0°C), raising the fresh air temperature to reduce heating demands.
Heat Exchanger Production | Heat Exchanger Manufacturer
Zibo Qiyu Air-condition Energy Recovery Equipment Co., Ltd., based in Zibo, Shandong, China, manufactures air-to-air heat exchangers and energy recovery systems. Their products include counterflow plate heat exchangers, cross-flow heat exchangers, rotary heat exchangers, and heat pipe heat exchangers for industrial and commercial use.
Heat Exchanger Production
- Product Range:
- Counterflow Plate Heat Exchangers: BQC series with cross-countercurrent structure for 70-90% thermal efficiency.
- Cross-flow Heat Exchangers: Perpendicular air flow for simpler applications.
- Rotary Heat Exchangers: Full and sensible heat types for heat and moisture transfer.
- Heat Pipe Heat Exchangers: Phase-change technology for efficient heat transfer.
- Sensible Heat Exchangers (BXB Series): Made from seawater-resistant hydrophilic aluminum, epoxy resin aluminum, or stainless steel, with 10-12% enhanced heat transfer surface, handling up to 2500 Pa pressure and 350°C.
- Manufacturing Capabilities:
- Integrates production, sales, design, and installation with customized solutions.
- Uses enhanced punching and biting techniques for <1% air leakage.
- Collaborates with Tsinghua University for performance calculations.
- Materials like corrosion-resistant aluminum or stainless steel, cleanable with tap water or neutral detergents.
- Applications:
- Industrial: Waste heat recovery, flue gas treatment, desulfurization, denitrification.
- Commercial: HVAC, data centers, ventilation.
- Environmental: Energy recovery for reduced carbon footprint.
Company Highlights
- Global Reach: Branches in Beijing, Guangzhou, Shanghai, Chongqing, Xi’an; serves Australia, Americas, Europe, Hong Kong, Taiwan.
- Innovation: Focuses on energy-saving, environmentally friendly products with advanced manufacturing.
- Contact: +86-15753355505
Does a heat exchanger remove humidity?
A standard air-to-air heat exchanger primarily transfers heat between two airstreams and does not directly remove humidity. The airstreams remain separate, so moisture (humidity) in one airstream typically stays within that airstream. However, there are nuances depending on the type of heat exchanger:
- Sensible Heat Exchangers: These (e.g., most plate or heat pipe exchangers) only transfer heat, not moisture. Humidity levels in the incoming and outgoing air remain unchanged, though relative humidity may shift slightly due to temperature changes (warmer air can hold more moisture, so heating incoming air may lower its relative humidity).
- Enthalpy (Total Energy) Exchangers: Some advanced designs, like rotary wheel or certain membrane-based exchangers, can transfer both heat and moisture. These are called hygroscopic or enthalpy recovery ventilators (ERVs). The core material or wheel absorbs moisture from the humid airstream (e.g., warm, humid indoor air) and transfers it to the drier airstream (e.g., cold, dry outdoor air), effectively managing humidity levels to some extent.
- Condensation Effects: In certain conditions, if the heat exchanger cools humid air below its dew point, condensation may occur on the exchanger’s surfaces, removing some moisture from that airstream. This is incidental, not a primary function, and requires a drainage system.
So, a standard heat exchanger doesn’t remove humidity unless it’s an enthalpy-type ERV designed for moisture transfer or if condensation occurs. If humidity control is a goal, you’d need an ERV or a separate dehumidification system.
How does the air to air heat exchanger work?
An air-to-air heat exchanger transfers heat between two separate air streams without mixing them. It typically consists of a heat-conductive core (like a series of thin metal or plastic plates or tubes) where one airstream (e.g., warm indoor air) passes over one side, transferring its heat to the core, while the other airstream (e.g., cold outdoor air) passes over the opposite side, absorbing that heat.
Here’s how it works:
- Warm Air Input: Warm, stale indoor air (from a building) enters the exchanger.
- Heat Transfer: As this air flows through the core, it transfers heat to the core’s walls, which are made of a conductive material like aluminum.
- Cold Air Input: Simultaneously, cold, fresh outdoor air flows through adjacent channels in the core, picking up heat from the core’s walls.
- Exhaust and Supply: The now-cooled indoor air is exhausted outside, while the warmed outdoor air is supplied into the building.
The process can reverse in cooling mode (e.g., in summer), where cool indoor air transfers its "coolness" to warm outdoor air. The airstreams are kept separate to avoid contamination, often using counterflow or crossflow designs to maximize efficiency. Efficiency can reach 50-80%, depending on the design and conditions.
Common types include:
- Plate heat exchangers: Use stacked plates for heat transfer.
- Heat pipe exchangers: Use sealed tubes with a working fluid that evaporates and condenses to transfer heat.
- Rotary wheel exchangers: Use a rotating wheel to transfer heat and sometimes moisture.
It’s used in HVAC systems to save energy by pre-conditioning incoming air, reducing the load on heating or cooling systems.
Heat recovery system for paint booth
The heat recovery system of the paint booth mainly recovers the heat from the exhaust gas discharged from the paint booth through a heat exchange device, which is used to preheat the fresh air or other heating needs entering the paint booth, in order to achieve energy-saving purposes.
In the heat exchanger, the high-temperature exhaust gas discharged from the paint booth and the fresh air (or other heated medium) entering the paint booth flow on both sides of the partition wall, and heat is transferred through the partition wall. Due to the lack of direct contact between exhaust gas and fresh air, the mixing of the two is avoided, ensuring the cleanliness of the air. The heat of high-temperature exhaust gas is transferred to the partition wall, which then transfers the heat to fresh air, raising the temperature of the fresh air and achieving heat recovery and utilization.
Application of Commercial Ventilation Heat Exchanger
Our commercial ventilation heat exchanger is a device used in the ventilation system of commercial buildings. Its main application principle is to use heat exchange technology to recover heat or cold from indoor polluted air while discharging it, in order to preheat or pre cool the fresh outdoor air introduced, thereby achieving energy conservation and improving indoor air quality. The specific principle is as follows:
Ventilation principle
Commercial ventilation heat exchangers are usually installed in the ventilation systems of commercial buildings, which use mechanical ventilation to expel polluted indoor air and introduce fresh outdoor air into the room.
This can ensure the freshness and circulation of indoor air, meet people's breathing needs in commercial environments, and also help maintain appropriate indoor temperature and humidity.
Heat exchange principle
There is a special heat exchange core inside the heat exchanger. When the air discharged from indoors and the air entering from outdoors flow in the heat exchange core, heat transfer occurs due to the temperature difference between the two.
The role of heat exchanger in sludge drying process
Heating medium: The heat exchanger transfers heat to the drying medium (such as air, nitrogen, etc.) to increase its temperature. The hot drying medium comes into full contact with the sludge and transfers heat to the sludge through convection, conduction, and other means, causing the water in the sludge to absorb heat and evaporate into steam, thereby achieving the drying of the sludge.
Recycling waste heat: During the sludge drying process, a large amount of exhaust gas containing heat is generated. The heat exchanger can cool the exhaust gas and recover the heat from it. The recovered heat can be used to preheat fresh air or drying medium entering the dryer, as well as for other process links that require thermal energy, thereby improving the energy utilization efficiency of the entire drying system and reducing energy consumption.
Removing moisture: During the sludge drying process, the heat exchanger can not only heat the drying medium, but also condense the water vapor in the drying medium into liquid water through cooling, thereby achieving dehumidification of the drying medium. Dehumidification of the drying medium is beneficial for improving its ability to absorb moisture from sludge and enhancing the drying effect. For example, in some sludge drying systems that use circulating drying media, by setting up cooling heat exchangers to dehumidify the circulating air, the drying speed of sludge can be increased by 20% -30%.