Should I replace a single powered roof vent with ridge vent according to my roofer's advice?

Question

I am new to home improvement, and I'd like to ask your advice. I am the owner of a house in Maryland. Within a few weeks, we will install a new roof. 

Currently, my roof doesn't have a ridge vent, and an attic fan only runs. My contractor told me he can add a ridge vent.

Do you think I'd better keep the attic fan running in addition to a new ridge vent? Both can be working together?

or 

do you think I'd better remove the attic fan, and have the new ridge vent only? It should be a good idea?

or

do you think I'd better keep the attic fan without installing a new ridge vent if Howard county doesn't require it.

I thought that in the long run, if the attic fan could cause any rain/snow/leaves-related leaking issues, it could be safer to remove it. The chance is extremely low? or my thought is a good idea? Usually, how often (in years) do I need to replace an attic fan with a new one?

I appreciate your advice in advance.

(Added)

Yes. we have soffit venting (under the eaves), and each vent on two sides.

However, I found that some portions of the soffit venting are closed somehow, maybe (see the picture). I am not sure how though. Should I clean them up ASAP?

Answer 1

In my personal experience, a "real vent" on top of the roof (cupola, turbine, etc) is far more effective than continuous ridge vent, and I will in fact be retrofitting a cupola onto a roof with continuous ridge vent for exactly that reason. The space feels nearly unvented, despite "being vented" as the air movement through the ridge vent (with plenty of venting at the eaves) is pathetic.

What you have there appears to be a "mushroom fan vent" rather than a turbine vent (i.e it only really moves air when powered up, while a turbine vent as I understand the term vents passively all the time and more actively whenever the wind blows.) That can be useful for increasing air movement in the space when needed, and should not be particularly prone to leak if it's in good shape. It would not meet code requiring passive ventilation, though.

I would strongly suggest reading the actual code applicable to your local area to see what it actually calls for, rather than accepting that it specifies "ridge vent" if, in fact, it simply requires passive vents but does not specify how that is to be done (which would be more likely, in my experience.)

Answer 2

I would keep the ridge vent and add the powered attic roof fan like one of your pictures shows. Done right (proper attention to flashing), the fan will not leak. And the powered fan is much more effective at clearing hot hot attic air than any passive system.

And do call the HoCo inspector's office. When I lived in HoCo, I found them to be very friendly and helpful. They want to help you do the job right.

EDIT 1 - Replacing the roof mounted fan

I've found the fan motors and mounting brackets to be fairly universal. I had the motor go out in my roof mount fan, and was able to replace it with a motor from another unit. Yes, I had to buy the entire unit, but at least I didn't have to remove & replace the fan housing itself, which was flashed and water-tight to the roof.

Answer 3

while you are trouble-shooting the paint-blocked soffits, you might check that they are not blocked inside your attic, especially if you have blown-in insulation. Check that you have "rafter vents" installed which provide for unobstructed ventilation from the soffits.

Answer 4

Several Power Vent Manufactures say you should only have ONE Type of Vent. Either a Ridge Vent or a Power Vent. Solar Roof Vent is another option; but not in the South (will explain later). You must either remove an existing Ridge Vent to install a Power Roof Vent. You will want you attic Roof Fan to have a temperature control from at least 70 to 120 degrees. The controller should allow the fan to kick on only when the attic temperature setting needs to be reached. Because we live in Houston Texas, we are told a Power Vent will do a better job than a ridge vent.
Most IMPORTANT - You CANNOT Have Both. Having a Ridge Vent and a Power Roof Vent is bad because it will pull air from the Ridge causing less air removal closer to the base/floor of your attic. The GOAL is to remove the Air above the Ceiling of your living room and other rooms. If you pull air from the Ridge Vents, your Attic Roof Vent will be Fighting to do its job. The attic roof fan will stay on longer than it should using more electricity and your A/C will use more electricity because your Attic Roof Fan is fighting to reach your attic Fan temperature setting. Then your attic fan will burn out faster. NOTE: Some residence have installed Solar Roof Fan. If you are in the South when Heat stays in your attic 2 to 4 hours after the Sun goes down; then your system is not energy efficient for you in the South. If is hard to find a solar attic roof fan that kicks ON the first 2 to 4 hours after the Sun goes down (unless has a solar battery pack storage or an electrical connect)t. Ideal attic temperature should do down to 100 - 105 degrees. Examples: If the Ambient air is 90 degrees, your attic will be above 105. If the Ambient is 80 degrees, then your attic will be around 90 degrees. Their are times in the South when Ambient at night is still 90 degrees 2 or more hours after the sun goes does. Setting a temperature on the an Attic Fan from 70 to 105 degrees is best. True, the lower the Attic Roof Fan temperature is set, the better temp in your house. You will need to decide if you want Roof Fan set to 70, bring attic temperature to about 80 or Attic Fan to 80 allowing attic to be around 90 degree.
In Summary: Soffits are good to have for air flow with an attic roof fan. Be sure soffits are not blocked by blown insulation or block outside by paint. The holes in the soffits need to be open. Ridge Vent or Power Vent (not both). If in the South, Power Vents are better to allow extended (2 to 4 hours of) heat at night to be removed - whereas most solar fans do not operate at night. If you have a Ridge Vent and you find Power Vent will do a better job for the area you live, then you will need to have the Ridge Vent Remove from outside or Blocked from within the attic. In my opinion, blocking a ridge vent is cheaper by using insulation to stuff in the vents and is cheaper. Remove the Ridge Vent will be costly since the you must remove the shingles, then remove the ridge vent, install new felt, and install new shingles. Remember the purpose of blocking the Ridge Vent, is to block air from coming in from above and allow the Attic Roof Vent to do its job from the bottom up.