Invisco Industrial offers both pure gravity ventilation in our Tornado Gravity line and hybrid ventilation in our Tornado Hybrid line.  Our model numbers are similar to those made by Edmonds because the fans are very close in form and fit but offer superior performance. The main difference is that the turbine on the Hybrid models is higher. 

The Tornado Gravity models include sizes from 4 inches (H100) up to 36 inches (H900). 

The Tornado Hybrid models are in 4 sizes – TP400 (16 inch throat), TP500 (20 inch), TP600 (24 inch) and TP900 (36 inch). 

For the TP900 data sheet click this link below.

For the TP500 data sheet click here –

Here is a comparison Edmonds, Invisco and two older American rooftop ventilation sources: 

CSR Edmonds in Australia was the first to bring hybrid rooftop ventilators to the United States. The Edmonds design sacrificed performance under power to maximize performance with no power. Edmonds made the decision to motorize the turbine head. This resulted in a reduced air flow when there is static pressure in the system. Specifically the Edmonds EP900 36 inch throat hybrid is rated at 5,885 CFM under full power at 0.0 SP. But at 0.1 SP that falls off  to 2500 CFM. It cannot pull air at 0.2 SP. Here is their performance graph for the EP900 :

Here is the Tornado EP900 performance graph. The addition of a simple propeller blade on the motor increased the output dramatically and offers excellent air flow at much higher static pressures. 

If you have seen the Edmonds products, you know they are priced high because of the cost of shipping from Australia. 

Invisco ventilators are made in America. The prices below include shipping to any location in the continental United States. 

Description                                                     EdmondsUSA                   Invisco    

Tornado  H400T (16 inch throat)                   $414                            $295

Tornado  H600T (24 inch)                                $987                           $695     

Tornado  EP500 (20 inch throat)                      n/a                             $2224
CFM  at 0.0 SP                                                                                              8,000
Watts   At 120 VAC                                                                                           505
CFM per watt                                                                                                        16

Tornado   EP900T  (36 inch)                            $3530                            $3795
CFM  at 0.0 SP                                                        5885                           14,000
CFM  at 0.2 SP                                                                0                           10,789
Watts   At 120 VAC                                                   273                                  975
CFM per watt                                                               22                                    14