It is extremely important for the soffits to be totally unobstructed in order to allow the exterior air to pass freely. The combination of soffits and the appropriate Maximum ventilator, strategically placed, provides a chimney effect that uniformly sweeps the attic to eliminate all heat build-up or humidity. 

If the soffits are blocked by insulation or any other material, use a styrovent to clear them out in order to have adequate attic ventilation.

In the case of walls reaching the roof itself, which blocks all possible ventilation form the soffits, Ventilation Maximum recommends the use of fresh air intakes or special ventilators known as VMAXAT1 or VMAXAT2, uniformly positioned at the eaves.

This will allow exterior air to enter into the attic and to circulate evenly; the peak ventilator then draws and exhauts all excess heat and humidity.

It is very important to seal all openings that would allow air to enter elsewhere than through the soffits.

If this is neglected, these openings located at the rafter level will inhibit ideal air circulation, which starts at the bottom and rises. The air that comes in through these openings will be drawn up by the ventilator, limiting air circulation to the rafter area only.
 
 

Roof louvre ventilators do not produce a chimney effect. Their effectiveness is limited to evaporation. 

They also present a definite risk for snow or water seepage. Above all, as soon as snow accumulates and covers them, they become useless especially when they are needed the most. 

The effectiveness of one Maximum ventilator is greatly superior to that of four roof louvre ventilators, with no risk of becoming ineffective because of snow accumulation or penetration.

Ambient temperature and humidity rise rapidly in any attic with a limited air space.

The solution is to increase ventilation, making sure that there are no openings other than the soffits and the Maximum ventilators installed at the gable using a rooftop flashing, or on the rear slope of the roof.

Dormer windows, being located at the soffit level, reduce the air intake because of the loss of soffit space. 
 
In this case, Ventilation Maximum recommends the installation of a special product : our stormproof ventilation louvres which do not allow snow to enter and ensure an air intake far superior to that of the standard soffit, enabling adequate ventilation to this problem area. It is also preferable to install the ventilators on the side of the roof opposite the dormers.

The soffit on the side of the shortest slope be 50% blocked, leaving the soffit of the opposite slope completely open. 
 
This balances the chimney effect and makes ventilation more efficient due to the joint action of the soffits and the Maximum ventilator. 

Drawn air enters and circulates evenly; the ventilator then uniformly exhausts excess humidity and heat from both sides of the roof.

Inadequate aeration through the soffit may be caused by a piece of wood or brick at the junction of the mansard and the roof which is blocking air passage. Ventilation Maximum recommends using its special products installed near the eaves of the roof; fresh air intakes or special ventilators VMAXAT1 or VMAXAT2. 

Is your turbine causing problems? 
It`s noisy, stop operating in freezing rain, and lets in water and snow! 

Here`s the solution : Ventilation Maximum manufactures replacement heads to exchange those noisy and defective models. 
A very simple installation is required : 
Remove a few screws from the existing turbine. Remove the old turbine and, 
Install a Maximum ventilator #401

Our adapters make our #401 model easy to install. The old turbine can be replaced whether it is 10, 12 or 14 inches in diameter, leaving in its place a ventilator that is quiet, efficient, reliable and safe.
  

With the presence of warm air vent discharge in the attic or close to a soffit, heat is drawn in the attic forming condensation which causes serious damage to the roof and insulation. 

To correct this problem, Ventilation Maximum recommends the installation of an additional ventilation duct with a roofcap to direct the flow of warm air outside away from the roof and at a suitable distance from the soffits. This prevents the possibility of hot air melting the surrounding snow which could cause an accumulation of ice.

Since the side with the cathedral ceiling is more difficult to ventilate, leave the soffit 100% open on this side and install Maximum ventilators on the non-cathedral side in order to force the flow of air to its direction. 

Partially obstructing the soffit on the non-cathedral side produces a balanced attic ventilation. 

This type of building requires installing a Maximum ventilator for every 600 square feet of insulated ceiling. 

Block the uppermost soffit and leave the lower one completely open, then ventilate at the gable of the roof to create a chimney effect. 

As the air volume in this type of attic is minimal, adding a second Maximum Type B ventilator to the cathedral ducting system doubles the ventilation capacity. 

There should be no other opening aside from the lower soffit and the Maximum ventilators.The lowest ventilator louvre must always be at least 6 inches above the highest point of the roof.
   

For cathedral roofs the Maximum ventilator is absolutely essential. Given its superior drawing capacity it evacuates a large amount of hot, humid air. In addition, because of its height, you can always be assured of this efficient performance as it will never become covered by snow. 

An insulated air duct is therefore installed along the whole length of the roof`s gable. This will ensure sufficient ventilation between each roof joist. Air is drawn in through the soffits between each joist and is consequently evacuated by the Maximum ventilators.