I have the Abbaka 1400 CFM blower. It's mounted on the roof but unfortunately the construction project isn't finished so I haven't been able to try it yet. It is a very solid well-made and nice looking unit. I got a great price from www.dvorsons.com.

Billy

Did your install require any elbows? What's your estimated completion date? I still have to order cabinets, hopefully next week. I purchased both the blower and MA liner from Dvorson's, lowest combo price I could find.

My install is a straight shot to the roof in about 7-8 feet from the top of the liner. I also plan to install the fantech silencer. I must say I was a little shocked when I read the one elbow requirement. Not sure if I add a elbow that I will have enough vertical distance to fit the silencer. The DW's one request was to make sure the ventilation system was quiet. I guess we'll see.

Did your install require any elbows? What's your estimated completion date? I still have to order cabinets, hopefully next week. I purchased both the blower and MA liner from Dvorson's, lowest combo price I could find.

My install is a straight shot to the roof in about 7-8 feet from the top of the liner. I also plan to install the fantech silencer. I must say I was a little shocked when I read the one elbow requirement. Not sure if I add a elbow that I will have enough vertical distance to fit the silencer. The DW's one request was to make sure the ventilation system was quiet. I guess we'll see.

Yes, my install requires a couple of elbows so I am fine there. Unfortunately I don't have room for a silencer but I think it will be pretty quiet.

The completion date is a long story because we began the 7 month project last June but the contractor went bankrupt (more or less) and a new contractor started about a week ago.

Billy

On second thought about the statement " for lowest possible noise there should be at least one elbow", I guess there are rare installations that only require 1 elbow.

After further measuring, I'm not going to be able to run a straight shot to the roof. Due to the units protrusion normal to the roof slope, it moved to close to the valley for my liking and is prohibited in the other direction by the cathedral ceiling.

So now I have two choices: install towards the driveway were it can be seen from the street or install towards the deck were it can be seen and heard while sitting on the deck. Also the deck location would require twice as much duct.

What is the consensus location?

Less desirable mounting locations, in no particular order:
o where the wind blows up the roof into the fan
o where the exhaust blowing down the roof reaches potentially open windows or people sitting on decks
o within 10 feet of any intake vent (actually, this is prohibited)
o where snow naturally drifts
o where you can't reach from inside the house
o where it spoils the view of the roof

My exhaust vent assemblies (there are 6 on my roof surfaces for various purposes) are visible only from the back yard. However, my MUA intake roof vent is on a sloping side roof visible from the street. This mounting location was selected to get it far enough away from the other vents and the furnace chimney.

The MUA intake has a cap at least 3 feet in diameter, and is at least 3 feet high on the low side. I was riding with a neighbor one day and remarked on how obvious it was and he claimed that he hadn't noticed it, even though it had been installed months before. I guess the leopards are right, humans don't look up.

Few residential exhaust assemblies are as big as this unit, and certainly not the Abbaka, which is fairly low. So, while it may be visible, it probably won't be visually intrusive, even on a street side. Paint it the same color as the roof shingles for reduced contrast.

kas

I've decided on the driveway location.

Watched some videos today for installing roof fans and it seems fairly simple. I think I will give it a shot when needed.

Did not realize until I was reviewing the installation details that the flashing is only a 1.5" wide. I wish it was 3 to 4" wide. I live in Mobile, Alabama and we get a lot of rain. Every year its a battle between us and Seattle for the most rainfall. We average 64" per year.

I plan to caulk the unit to the roof and the shingles to the flashing but to me Abbaka could have put a wider flashing on the unit.

Layered aluminum flashing such as skylights are installed with would seem to be a good idea. How much overlap is needed would depend on the slope of your roof, I would think.

kas

Billy_g, how long has your unit been installed? and I assume since you have not mentioned it that the unit is not leaking.

It concerns me the installation instructions state "3. The ventilator must be sealed between the roof and its underside with QUALITY roofing mastic." I can see doing this as a precaution but if one is concerned with water getting underneath the unit you would think they would have made the flashing wider. Also, it seems to me the damage is already done if water gets this far.

The instructions also state "The flashing on the discharge side of the ventilator must rest on top of the shingles" which is standard for any roof mounted structure, yet the two pictures

http://www.modernaire.com/Motor_Options_files/BrochureHyExCurrent11.06_4.pdf

of installs do not show this requirement.

And yes I'm very concerned with the seal of this unit to the point I'm thinking of returning. Should have noticed this before ordering.

Does any one have their hood installed only 1/8th of an inch in on one side of the box. We have a steep ceiling and the hood and stack are 72 inches high where the high point of my ceiling is 109. I think they mis-measured the height. Abbaka is not helping me. I wish I had never seen their hoods. They are beautiful, but my husband has been yelled at by the salesman and it seems like the stack is 2 inches short and all they say is it only needs to be in an 1/8th of an inch. My sheetmetal contractor, contractor and roofer all say it should be at least 2 inches. What is the point of the box if it only has to be in an 1/8th of an inches. Can any one help me? At this point I have to have the hood at 75 to 76 inches from the floor. I will barely be able to reach the controls.

I'm having a little trouble grasping the underlying meaning of this question. Is this a liner that is too far up in a wooden cabinet such that the requirement for keeping combustibles protected above the stove is being violated? Is the ducting exposed ducting but too short for the desired hood height?

kas

If this is off topic, my apologies - I need to specify my hood system in the next week or so. People on the list seem to like the Abbaka so I've been looking at their blowers. I want to put the unit on the roof, and will deal with the rest of the interior part soon. My question is -- how loud is the blower on the outside? The house is practically all windows and I'm concerned that putting the blower on the roof is going to be pointless because the noise will come in the windows anyway.... And if I have a run of about 25 feet, do I need a silencer?

Help? And thanks.

I don't have an Abbaka, but if you have room for one (see Fantech for details), a silencer can help reduce blower noise passed back down the ducting, particularly the higher frequency blade turbulence noise.

I would be surprised if the noise would be obtrusive through modern closed windows, but you might hear it through a nearby open window. With a run of 25 feet, one would expect that any sound making it back into the kitchen would not be a conversation stopper.

An alternative roof mount exhaust blower could be selected from various modest-sized up-blast fan assemblies (of the style restaurants typically use). They should have a sound peak in the vertical direction. Broan/NuTone may still make some, and certainly commercial suppliers such as Greenheck do.

kas

The Abbaka on the roof has not been a noise problem. That being said:
- the kitchen is on the first floor and the roof is above the second floor
- we have all new windows that seal well
- the Abbaka is above our master bedroom and there ain't no one in there when we're cookin!

Billy

Kaseki & billy_g, thanks. I should have mentioned that this is a one-story house, new construction and windows, but there are LOTS of windows. We're in a climate where windows are open a lot of the time -- all but the coldest winter days (which for us is usually about 50 degrees) and nights.

The wall that will have the ducting is shared with a bedroom, but we're planning to insulate that wall. We also plan to insulate the ceiling (attic above).

The house is very-open-plan, and DH is absurdly noise sensitive, so I'm trying to really minimize sound levels. Does this change anything, IYO?

Thanks. Really.

It tends to push the solution space toward a larger fan run at a lower speed. This is something that could be discussed with Abbaka, Fantech, Greenheck, or whomever you chose to be your supplier.

kas

Also a larger capture area (meaning a wider hood, a hood AT LEAST 27 inches deep, and air space within the hood and below the baffles for the effluent to billow) will let you run the fan at lower speed.

There will be air noise across the baffles regardless. You can get in-ceiling speakers to mask the noise... :-)

Don't use mesh baffles.

Billy

Burnt,

I have the 1400 Abbakka roof-mounted blower...we have one elbow and opted for the silencer as the pipe runs through my son's bedroom closet upstairs before reaching the blower on the roof.

The blower is extremely quiet. At high speed it does raise the noise level slightly right at the range, but very, very quiet upstairs. We are very satisfied with the blower. It handles most smoke/vapor however when grilling smokey items (steaks that aren't fully trimmed, etc.), some smoke does escape into the room and can be seen roiling around the ceiling lights. Nevertheless it is not bad enough to make it unpleasant to be in the kitchen. Otherwise it captures everything.

I attribute the grill smoke issue to two factors that have nothing to do with the Abbaka blower:

1. We have a highback with shelf that interferes somewhat with smoke escaping directly upward and
2. While we bought an overwidth hood for our range (54" inch hood for a 48" range) we elected to go for a 24" depth instead of a 27" depth. Not sure i'd make that choice again, although for most applications it makes standing over the range more pleasant for me and my height).

Good luck!

BFF, thanks! Did you get the Abbaka silencer or a Fantech or...??

I talked with the Abbaka people today and I'm just about committed to the 1400 cfm Hy-Ex roof mount. But they also told me that if we put in two 90 degree angles the way the HVAC guy suggested, we probably wouldn't need the silencer. (Note for anyone else trying to figure this out - they said to have 12' between the angles, and to be sure to use adjustable elbows.) Abbaka also told me that the silencer can be added later, if we decide the noise is too loud - it's just cutting out a section of ducting and splicing in the silencer. (Won't be comfortable working in the attic, but that's why the HVAC guy gets the big bucks, right? )

Ha! Yes...i'd follow Abbakka's advice. Why spend the extra dough unnecessarily? We did use the Abbakka silencer and it is fantastic.

Before pulling the trigger on your blower, make sure the hood you want is compatible with the infinite adjustment blower on the Hy-Ex. Obviously the Abbakka hoods are fine as are ModernAire or the Eurostoves version of the Modernaire. Others could work too, but a 3 or 4 speed switched hood won't work without modification.

The variable speed control that comes with the Abbaka blower is the same as the one that comes with a Modernaire hood and it is the same as the ones I bought to lower the speed of my bath vent fans. In other words it is a standard motor speed controller that you can buy anywhere -- don't you love it when they design with parts that are easy to find?

Billy