[keveyem]

Hi all,

I posted this in the carpentry thread and then searched for related issues and some of them were re-posted in this section, so I figured I'll re-post it here. If the forum mod feel it aint right pls delete them, willg et you a beer for your extra work :thumbup:

Anyways, this is what I wanted to ask,

I've got a tricky problem, atleast tricky for newbie DIY guy.

We have a GE Profile range, and it has a cook top and microwave with hood, vented to outside wall.

We cook a lot of oily, greasy stuff, so I figured I will get a dedicated range hood as the one in my microwave wasn't that effective.

So I bought a Franke EuroPro 30" hood. Here is the spec and installation pdf link.

http://www.frankeksd.com/specviewer.php?prodid=385
http://www.frankeksd.com/grfx/pdf_fi...EuroProINS.pdf

I removed my microwave, and the cabinet above it. First off I noticed that, Franke hood has the vent hole on top, while the microwave had the vent on the back side. To make it worse, the Franke vent hole is circular (6" dia) while the microwave is rectangular (oval) shaped.

Another issue is, the cabinet was mounted right on the rectangular vent, so if I install the new hood undearneath the cabinet, I wouldnt be able to use the round to rectangle transition.

So, should I remove the drywall, take the existing rectangular vent, add a circular vent tube, increase its height, put vent holes in my cabinet and then connect the hood to it?

What is the best way to attach the Franke hood to the existing vent? Can I use flexible metal duct from Franke to the existing vent or should I replace the existing square vent to a circular one??

Ive got some pictures in the following links, it would be great if any of you can give me a suggestion.

http://img22.imageshack.us/img22/2041/dsc5395.jpg
http://img26.imageshack.us/img26/5521/dsc5399x.jpg
http://img149.imageshack.us/img149/6554/dsc5401.jpg
http://img200.imageshack.us/img200/3827/dsc5402.jpg
http://img91.imageshack.us/img91/1191/planz.jpg

Thanks in advance

 

[Yoyizit]

If you can't find a commercially duct transition
http://images.google.com/images?cli...ion"&oe=UTF-8&um=1&ie=UTF-8&sa=N&hl=en&tab=wi
that works for this application you may have to make your own.
You may also need a booster fan somewhere.

 

[keveyem]

Yoyizit,

Thanks for the suggestion. I did find the duct transition,its with me, the only problem is If I use them, then I cannot use the existing vent on the wall, as it adds up 9" more.

How easy is to remove the rectangular vent heads thats already in the wall and replace it to round one? If thats easy, then I'll just remove the vent head, use 2 45 degree transitions and connect it to the wall.

 

[hvac122]

The first concern that you should have is that with 600 CFM going out if you have any gas appliances (furnace, water heater) or firepalce you will backdraft them and pull carbon monoxide or smoke back into your house. This is spelled out in your installation manual. Fresh air will need to be brought back in and you furnace blower interlocked with the hood so that when the hood comes on the furnace fan draws in the fresh air to replace whats going out.

That being said for the vent you will need to cut out the cabinet floor and then the wall to the outside, assuming it is on the other side of the wall. Install all rigid pipe with no skrews and a new cap outside. Abandon the old vent.

I would suggest that if you do have gas appliances you get a hood that vents out the back and is 300 CFM or less.

 

[keveyem]

hvac122,

Thanks, I did read about the CO2 issue. My furnace and heater is in the basement. The fireplace is in the living room and Ive got plenty of room in between.

Also, is there any reason for abandoning the old vent?? Is it because of the elbows and joints needed to use it for the new one, or some other reason?

TIA

 

[hvac122]

I guess I don't see how you are going to get to it but if you have a way and it is big inough then go for it. Follow manufactures instructions as far as size and how many turns for length you can do.

It dosn't matter where the appliances are in your house as the new hood will put the whole house in a negitive pressure and the easiest place for it to come in is through the flues and vents. Distance means nothing. Air will follow the path of least resistance. I would suggest a call to the local codes department for answers.

 

[keveyem]

hvac122,
I understand the point, we dont use fireplaces normally and we will use the hood fan only about 30 mins a day in the evenings.

So far this is my plan, cut the drywall and extend the existing oval vent up 10" and then connect the hood vent to a round to oval transition and connect it to the newly extended vent in the wall.

I've attached the plan in the picture.

Let me know if there are any do and dont's.

*Edit:
I will also put a CO2 monitor in the hallways, just to take care of the CO2 issue.

 

[drtbk4ever]

It doesn't matter where the appliances are in your house as the new hood will put the whole house in a negitive pressure and the easiest place for it to come in is through the flues and vents. Distance means nothing. Air will follow the path of least resistance. I would suggest a call to the local codes department for answers.

Keveyem,

Don't ignore the advice of Hvac122. Your family's life may depend on it.

I too will be replacing my range hood and will follow your progress.

Best of luck.

 

[hvac122]

I see very little in the instructions about how many turns and such they would allow and how many feet it can be vented so you may be OK doing what you want. Make sure it is all hard piped.

I can't strress how important fresh air for your house will be using this hood. It dosn't seem to bother you so do what you want and put the family at possible risk. It is code here and we have to allow for it.

 

[Yoyizit]

There are rules for "combustion air" based on the tightness of the house & volume. It's in the IRC.

"Symptoms of carbon monoxide poisoning include listlessness, depression, dementia, emotional disturbances, and hallucinations. Many of the phenomena generally associated with haunted houses, including strange visions and sounds, feelings of dread, illness, and the sudden, apparently inexplicable death of all the occupants, can be readily attributed to carbon monoxide poisoning."

 

[keveyem]

hvac122,
So you suggest that I should talk to a hvac repairman to see if I can install the hood??

I did speak to a handyman who looked at it and said its ok to do, he did ask for $400 for installation which made me think that I should do it on my own.

So to satisfy and go by code, what should be my next step??

 

[keveyem]

There are rules for "combustion air" based on the tightness of the house & volume. It's in the IRC.

My house is about 3000 sq.ft with 2 level and a 1300 sq.ft basement. But I guess the numbers dont mean much as hvac122 says if there is a net negative airflow then the air from chute and flue will be pulled in.

Also, as a side pointer, the previous hood was rated 300 cfm and I can say it didnt work that well, the pictures and my light fixtures which are about 10' away from the range has a layer of oil in it.

 

[keveyem]

Thanks hvac122. If you didnt caution me, I wouldnt have noticed about the backdrafting that you talked about.

I read these 2 links. I have 2 windows right next to my range, we do always open them when we cook so as to get more fresh air, I will keep doing the same.

http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/97/971104.html
http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/91/910512.html

I also looked in to one of the following solutions,
http://www.oikos.com/esb/39/VentOpt.html

I know air exchangers are pretty good, but I dont want to drop in a grand, so what is the cost effective option other than opening up the windows?

TIA

 

[hvac122]

hvac122,
So you suggest that I should talk to a hvac repairman to see if I can install the hood??

I did speak to a handyman who looked at it and said its ok to do, he did ask for $400 for installation which made me think that I should do it on my own.

So to satisfy and go by code, what should be my next step??

I am not saying that you can not install the hood. All that I am saying is that if it is removing 600 CFM then that air must be replaced from someplace. If you don't have a leaky house then air will get into the house the easiest way it can find. This can cause backdrafting of your appliances. This is a design issue and a service tech may not have the answer. Do you have a local codes enforcement office? That is where I would start unless the remodel is being done without permits? They are there for your safety and should be able to give you some ideas on what they expect. Here, a range hood requires a permit.
A properly sized and installed range hood will take care of your problem. The guy at the appliance store just wants to sell a larger unit for more profit.

 

[hvac122]

Thanks hvac122. If you didnt caution me, I wouldnt have noticed about the backdrafting that you talked about.

I read these 2 links. I have 2 windows right next to my range, we do always open them when we cook so as to get more fresh air, I will keep doing the same.

http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/97/971104.html
http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/91/910512.html

I also looked in to one of the following solutions,
http://www.oikos.com/esb/39/VentOpt.html

I know air exchangers are pretty good, but I dont want to drop in a grand, so what is the cost effective option other than opening up the windows?

TIA

There are many ways to bring fresh air into your house. Opening a window is one way but will the next owner know to do this and the risks if they don't? Another is to cut a hole in the house and just leave it open. Not very cost effective.LOL One way we do it here is to have an opening to the outside and run that to a mechanical damper. Then tie this into the return air system as far from the furnace as possible. Interlock the furnace blower to come on and the damper to open when the range hood comes on. The main problem with this is the furnace manufacturer dosn't really want fresh freezing air to hit the heat exchanger for fear it may crack it. Another way is to just not hook up the fresh air to the furnace and let the damper open when the hood is on. Suplemental heat and/or cooling may be needed with any option depending on the size of the hood and how much air is comming in. These are just a few ways to do this.

Good luck

 

[Yoyizit]

300 cfm. . .didnt work that well
pictures and my light fixtures which are about 10' away from the range has a layer of oil in it.

I guess I'd first find out how much airflow it takes to reduce the grease to a reasonable level: 600 CFM, 900 CFM, more? I'm not sure how to find this out. The people who make vents for commercial kitchens probably would know.
If your grease particles are too large and heavy to be carried along with slow moving air and get scattered instead, there may be no CFM level that works unless you also use visually displeasing baffles. It may also depend on what you're cooking.

Anyway, assuming you find a usable CFM rate then deal with the problem of replacing combustion air.

That's why home improvement contracts say "furnish and install." They never promise they will solve the problem.

 

[keveyem]

I just checked my township websites, it does not say anything specific to hoods, but I put in a voicemail to the code regulator explaining the situation and asking her to give me a call back.
Once I hear back from them, I have a worksheet here to find out the amount of combustible air my gas appliances will use (i got it from my twnship). If they say there is no code violation, then I'll go ahead and install the hood and bring in a hvac guy to measure the air pressure and if there is a negative air pressure, I'll find more about getting in a heat/air exchanger.