Is there a QUIETER Fan In a Can/Drum?

JUGHNE

Have a steam boiler... 525,000 BTUH input in a church basement.
It is a Dunkirk 246B-6, atmospheric burner.

The insurance inspector was here today and asked about combustion air.
I pointed out there was no dedicated opening and also that there was a fair amount of exhaust fan CFM created from a little used grill hood in the next room.

BTY, there is also a gas fired non-vented dishwasher in the room with the grill hood.

(I have brought this up several time concerning combustion air.....but the local yokel knows little.....and this building has been here for 100 years.) There have been major window upgrades since etc.

So finally with an expert (he traveled over 200 miles to get here) recommendation we will have to consider some form of combustion air inlet.
I am looking at a CAS-6 with 8" inlet. I have one of these on another job and am concerned about the noise level.
Does anyone know of anything quieter. The boiler room is under the altar area of the church.

Tinman

Is there any way to do it passively? Motorized damper?

EBEBRATT-Ed

Maybe a window you can take out. Motorized damper spring return with an end switch

STEVEusaPA

To me this brand seems quieter. http://tjernlund.com/commercialInforcer.htm

JUGHNE

I have considered that, but if I read the book correctly with 1 sq inch per 2000 btuh that is a 16 X 16 inlet.....2 times. One high and one low?

Most motorized dampers I have encountered leak a considerable amount. The only wall available is to the north and this is NE....known for NW wind.

The FanCan would have only a single 8" hooded inlet which the wind will still hit but I believe with less off cycle infiltration.
This system goes into deep set back for 48 hours then temp up for 72 hour then set back for 48 hours. Most of the plumbing is in the boiler room.
Actually the FanCan with a motorized damper would be the best for this situation. Massive masonry construction with no wall insulation.

Jamie Hall

Passive would be better, as @Stephen Minnich and @EBEBRATT-Ed said -- but, if you can't do that, you may be able to quiet the thing down some. If you create a rectangular duct considerably bigger than you think you need, with at least one offset in it, and line it with acoustical tile, that will help some. So will mounting the fan so that it has flexible connections to the ductwork (both intake and exhaust) and is itself on vibration isolating mounts.

If the church has a pipe organ, and employs a technician to tune and maintain the organ, talk to him or her. Organ blowers are powerful gadgets, and have to be carefully silenced. The organ builders and technicians are very experienced and skilled at that sort of thing.

JUGHNE

If the Tjernlund has ducted inlet and outlet I can see it being quieter. Them and Fan/can/drum are the only power inlet vents I have seen.
The issue with passive/motorized louvers is that this is a church with a lot of "helpful" volunteers. I can visualize plastic duct taped over these cold air leaks...........anyone who works for a church or such knows what I mean.

Jamie, just a point of interest. We used to have a pipe organ, (1915 construction). It has since been replaced at least 3 times by electronics. We still have the pipes in place for ascetics. The small boy operated hand bellows was replaced by a blower when electricity came along. That blower motor was located in the basement 2 stories down with 8" pipe run up to the loft. The small boys were probably less noise than the basement blower by the way. It is very interesting how the pipes were tuned. On the back side of each pipe there is a slot cut in the metal, there is a strip of tin rolled down to produce the desired tone. Reminds one of a sardine or old coffee can operation. Not many here have see those cans, but I am sure you know what I am talking of.

Jamie Hall

Pity about the pipe organ -- properly maintained they last forever (there are some in Germany which are 400 years old!). Electronic ones don't. And yes, the tuning mechanisms are fascinating (and a side note -- wooden pipes and metal pipes go out of tune in opposite directions when the temperature changes...). For what it's worth -- in another life some time back, I earned my daily bread as a church organist. Which explains why I thought of it!

Tinman

@JUGHNE - We do a lot of work at churches so I know what you mean. The end switch on the damper will be your friend in that situation.

JUGHNE

So you have to visualize the damper open with end switch firing boiler, but damper outside covered by plastic.

However, right now there is no opening to the outside. I have tried to crack a window in the boiler room, no one will believe that it should be completely open/removed to meet the actual requirements.

When they cook the pancakes or use the gas fired/unvented dishwasher, there is usually a door open to that room. Someday this might catch up with the odds.
The chimney is 18 x 24 and maybe 50' tall. So plenty of draft.
On a really cold day after setback there may be a few seconds of roll out of the draft hood, but the draft is soon established.
As I said, I know it needs some combustion air and finally the "expert", (great guy by the way, the only one of many years of inspectors who questioned the air inlet) will put it in writing that it is required.
I may add a manual switch they can use for the hood and DW operation if the boiler is not firing.
Thanks for all the input.....another summer job to keep the grandson busy.