A greenhouse ventilation fan is part of an airflow system. Its frame size or free-air rating does not, on its own, describe what the installed arrangement will deliver. The useful comparison includes the air inlets, shutters, screens and any cooling pads, alongside the fan and its controls.
For a greenhouse owner, the goal is to request a proposal that explains these relationships clearly. This guide sets out the main questions to resolve before ordering a replacement fan or specifying ventilation for a new project.
Separate ventilation from circulation
UF/IFAS Extension describes greenhouse ventilation as exchanging internal air with outside air, using natural forces or mechanical equipment. Its guidance considers temperature, humidity and air movement across different seasons. The project brief therefore needs more than a description of the hottest day.
Internal circulation has a different role from air exchange. A Nik-Andishan circulation fan is a product for discussing movement within the growing space, while an exhaust fan is considered as part of the route by which air leaves the building. Define which problem you are trying to solve before comparing these products.
Prepare the site and operating information
Send the greenhouse layout, dimensions, covering and intended crop arrangement. Describe the existing openings and identify any screens or cooling pads in the proposed air path. For a replacement, supply photographs of the fan opening, shutter clearance, electrical connection and relevant model labels.
Explain how the greenhouse is operated throughout the year. If separate sections have different crops or schedules, include that information. A supplier should be able to distinguish the conditions provided by the customer from the assumptions that still need confirmation.
Ask for airflow at the relevant pressure
The UF/IFAS publication Fans for Greenhouses explains fan performance in terms of airflow, pressure and characteristic curves. This provides a better basis for comparison than a single maximum airflow figure. Ask the supplier to identify the conditions associated with the quoted performance and the version of the fan being offered.
For a Nik-Andishan 140 × 140 cm exhaust fan with automatic shutter, confirm the mounting dimensions and electrical requirements as well as the performance information. The listed size identifies the product format; it is not a statement of the ventilation requirement of every greenhouse in which it could be installed.
| Part of the enquiry | What to clarify |
|---|---|
| Fan performance | Airflow, pressure basis and the specific model offered |
| Air path | Inlets, screens, shutters, pads and obstructions included in the review |
| Installation | Opening dimensions, access, electrical work and responsibility for fitting |
| Operation | Control stages, seasonal use and maintenance access |
Review the inlet and cooling arrangement together
Ask for a simple explanation of where replacement air enters and how the proposed equipment serves the growing zones. If a cooling pad is included, the enquiry should also identify its water supply and maintenance arrangements. Request the reasoning behind the complete package rather than treating each component as an unrelated purchase.
Describe restrictions that may change over time, such as dust accumulation or the mature crop. These observations help the technical team identify what needs to be inspected and maintained. They are not a substitute for a design review or a measured performance assessment.
Agree installation and handover checks
Clarify who prepares the opening, supplies the electrical connection and checks the completed installation. Request the relevant operating instructions and the scope of any start-up review. The customer should know how to report a problem and which service information to retain.
For existing equipment, record a useful baseline before making changes. Note the operating configuration, relevant environmental observations and maintenance condition. Without that context, a comparison between the old and new arrangement may attribute a seasonal or operational difference to the fan alone.
Frequently asked questions
Can two fans of the same size have different performance? Yes. Ask for the specifications and performance basis of the actual models rather than comparing frame dimensions alone.
Should heating and ventilation be discussed separately? Their equipment roles differ, but the operating plan should coordinate them. UF/IFAS notes that moisture management can require ventilation during the heating season, which makes a seasonal control discussion important.
Discuss a ventilation enquiry with Nik-Andishan. Include the site, layout, existing equipment and the problem or operating requirement. For a new development, start with our greenhouse project planning guide; for cold-season requirements, see our heating selection guide.