DIY Home Improvement Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
Hi there,
Can anyone advise me on what I want to do.

I am building a 2 storey house and want a really good strong vent for my stovetop. So I ducted to the roof via a chimney soffit and am thinking of installing a 1500 cfm roof vent right at the top of the chimney. The vertical distance from my hood to the top of the chimney will be about 14 feet.

In the past, when the vent only went outside the wall, the smells would drift up to the bedrooms on the second floor.

I will remove the current motor and fan built into the hood (do I have to?).

Any reason why the above won't work. Thanks for your input.
 

·
Registered
Joined
·
426 Posts
1500 CFM is a lot for a stove, unless you are in a commercial setting. That is 1500 CFM of heated/cooled air being vented outside and will have to be made up somewhere. There are hoods that are made for remote fans and they will work better, and with less noise, than removing the guts from a typical hood. Check on ajmadison.com, there are a lot of hoods there with good information.

A remote fan will be more quiet but you need to ensure that it is rated for the application--grease will build up and be a potential fire hazard.

Hopefully, some of the HVAC guys will be along to comment on details...
 

·
Registered
Joined
·
7 Posts
Discussion Starter #3
Thanks for the reply. Really appreciate it. I am actually running two 6" ducts together as the room beside it serves as a utility area. That's another reason why I put the fan up there so that it can pull air from both rooms whenever necessary.

I do realize about the grease getting up to the fan and fan motor, so I intend to make certain the grease filters are always well maintained.
 

·
30 year tech
Joined
·
427 Posts
At 1200 CFM you will be removing to much air from your house. How are you replaceing that air? Did you know that you needed to?

Do you have gas water heater, furnace or a fireplace? Without replacing this air you will backdraft these appliances and could bring carbon monoxide into your house. Also putting the house in a negitive pressure will cause more problems than you know.

Also removing all of that conditioned air will mean that you will need to condition more air in the house and could undersize your current system.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #5
Hi hvac122,

Thank you for your comments. I guess I should have written that this is a 2nd home I am building in the tropics. The air in the kitchen is not air-conditioned (no need ever for heating in the tropics). And no, there are no furnaces, gas water heater(s), or fireplace(s). The water heater is a heat pump.

With the above in consideration, would you advise me to go ahead?
 

·
30 year tech
Joined
·
427 Posts
I think you need to fly me down to install this for you as it will be a very hard job.:thumbup: LOL

Really with those considerations you should be OK.
 

·
GC/Master Plumber/Mech
Joined
·
1,517 Posts
Just installed a 48" gas cook top and hood in a residential application. The hood is also 48" wide and can move up to 900cfm and has a variable speed. The exhaust fan mounts to the roof and has a 10" connecting single wall pipe.

My advise is to find one that has the VS option..prety cool

With the exhaust fan on the roof it is super quiet.
 

·
30 year tech
Joined
·
427 Posts
Just installed a 48" gas cook top and hood in a residential application. The hood is also 48" wide and can move up to 900cfm and has a variable speed. The exhaust fan mounts to the roof and has a 10" connecting single wall pipe.

My advise is to find one that has the VS option..prety cool

With the exhaust fan on the roof it is super quiet.

What are your codes there as far as fresh air and backdrafting? Our inspectore come in the house, close it up and turn evrything on. If anything backdrafts they make us fix it so that dosn't happen. Kind of hokey way to do it.
 

·
GC/Master Plumber/Mech
Joined
·
1,517 Posts
Sorry HVAC I forgot to add that we added a fresh air/ make up air intake to the house

And

If you go down there to install can I go as well:(pleasssssssssse

This install was for a widowed lady with more money than GOD. She went around to different vendors purchased all the stuff and called and said come and install. The dumbass sold her this massive draft hood and could answer "So what do we need for make up air?" Just love salesmen it's all about the $$$$ the hood and exhaust fan cost over $2k. It was were two fools met.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #10
Thanks guys,

I think everyone should have a 2nd home in the tropics. Its been raining these past 2 weeks, so we have to postpone the beach for another 2 weeks. :tongue_smilie:

It's always great to have other ideas.
 
1 - 10 of 10 Posts
Top