FAQ Summary from the Maximum Website

For the full document or more information, go to the Maximum website. This information is only for Sloped roofs with an attic space (not cathedral ceilings or flat roofs).

Question: The building I want to ventilate is 2000 sq. ft. The ventilator, model #301 can ventilate up to 1200 sq. ft., and the model #303 can ventilate up to 800 sq. ft. Can I install one model #301 and one model #303 on the same roof?

Answer: No, you must always use the same model of ventilator, otherwise the stronger ventilator will draw from the weakest, therefore short circuiting the system. This is why we recommend that you block off or remove all other vents on the roof.

Question: How far apart should I install the ventilators?

Answer: The ventilators should be no further than 20 ft. apart from one another. Each unit should be positioned so as to ventilate an equal portion of the roof. If you have one ventilator, it should be placed in the centre, if you have two units, each unit should be positioned at ¼ distance from each end of the roof.

Question: What is the reason that you ask that the louvers past the peak by six inches?

Answer: The Maximum ventilators are activated by the wind, and knowing that the wind directions changes during the year, we want this wind to pass threw the louvers from all directions that it may come. This way, the ventilator will work efficiently year long.

Question: I've noticed on your web site that you want all gable vents, low profile vents, ridge vents, etc… to be removed or blocked off. Why?

Answer: The Maximum ventilator will draw from these openings being closer and less restrictive, rather than from the soffits.

Question: I have no soffits or air intake vents on my house but I do have gable vents. Will your ventilators still work and prevent ice damming?

Answer: No, The ventilators will draw from the gable vents and exchange the air near the top of the attic, but it will not draw from the eaves due to lack of air intake. You will need to install our VMAXAT-1 or VMAXAT-2 so that the ventilator may draw in fresh air at the eaves while picking up the moisture on its' way up and out the ventilator. You will also have to close the gable ends as to not short circuit the ventilator.

Question: I have a two sided slope roof with a 4/12 pitch. The footprint is 1200 sq. ft.. I would like to install your model #301, but my problem is that I cannot position it in the middle of my roof due to a 4 ft. wide chimney sitting on the peak. Can I install it on either side of the chimney? Will it still be capable of ventilating the entire attic? How close to the chimney should it be installed?

Answer: We recommend that you install two ventilators, one on each side of the chimney no closer than 4 ft. from the chimney. You can use the same model (it will only replace the air faster) or you can use our model #303. Make sure that the chimney is higher than our ventilator so that the smoke doesn't flow threw the ventilators. This could cause the smoke to enter the attic space when wind velocity is nil, especially night-time.

Question: Will your ventilators allow wasp or flies into my attic?

Answer: We have never encountered this problem, and we believe the reason is because there is to much air movement within the ventilator. Have you ever noticed that insects are never flying around breezy or windy areas?

Question: Would your ventilator not draw the heat out of my house having such a powerful drawing power?

Answer: No, if the house in question is well insulated per standards, has a proper vapour barrier and the soffits are unobstructed and balanced or exceeds the opening of the exhaust vents, this shall never be an issue.

Question: I have installed your ventilator on my roof, but I am still having some ice damming over my kitchen and washroom area. Should I install another vent?

Answer: No, we recommend that you verify your exhaust vents for your washroom dryer and kitchen stove. They are probably venting into the attic space or into the soffits which is a common practice in the building industry. We recommend that you have them rerouted out threw the roof using our model CT-4 which was designed for this purpose. The goal of attic ventilation is to remove moisture from the attic, not introduce it into the attic.

Question: My house is very old and does not have a vapour barrier and proper air intake. If I install one model 301 on a 1100 sq. ft building can I have some problems?

Answer: Yes, you can have some problems since our ventilators have a very strong drawing power. The vapour barrier is very important to prevent humidity and hot air from entering the attic space easily especially if there is no air intake. You can easily fall in negative pressure and thus increase your condensation problem. Before you install a ventilator you must find a way to open the soffits or add some other form of air intake to your building (see last two sections of the product sub- section on our web site). If you cannot add a vapour barrier, you must at least add additional insulation to your attic space. The addition of ventilation on the roof must be done progressively with our least efficient model the 302.