side venting in a high rise apartment using exhaustco systems

Are you talking about Exhausto? If you are then this is an exhaust fan that goes on the top of your boiler flue. All that it does is create a negitive pressure in the flue. They can be used in a sidewall application but that would depend on local codes and on the boiler.

We really need more information to help. What brand boilers are you planning on using, what is the existing flue or chimney.

If it is a chimney then you will most likely have to line it. In most cases the new flue is much smaller then the existing chimney. And because it is smaller then it is not to difficult to lower a new flue down into the old chimney. What we have done is setup a small jib with a wench. You assemble the new flue on the roof one piece at a time and lower it down the chimney. It goes togather pretty smoothly. Find a good sheetmetal contractor and they should be able to do a good job for you.

If you can give me some more information then I can help you better. You may not need an Exhausto-Vent system but you will most likely need to line the existing flue.

Good luck and I would be more then happy to help.

David

Hey sorry for the delay. Some more info. The boilers being used are RBI F3's 3 million BTU each, which are high efficiency which as mentioned require a double wall stainless steel liner. The original chimney is in rough shape and the building is 24 stories with the boiler room being located in the basement so the expense is astronomical to reline the chimney. The exhausto system being proposed is an inline system which will be sucking in fresh air to cool down the air temperature of the exhaust of the boilers which will hopefully reduce the size of the plume outside

I would think the hot exhaust would be used to preheat the in coming air.

Have you considered relocating the boiler room?

I have faced this same situation several times and in each decided to remove the chimney and replace with 3 wall stainless flue tubing. However if these situations had exceeded 7 stories in all probability I would have relocated the boiler room instead.

What you are talking about doing is pressurizing your chimney and I would be very surprised if the city inspectors would allow you to do that. If a Stainless steel liner is required by the boiler manufacturer then you are going to have to but a new liner in your chimney. And I really don't understand what you are talking about with a low plume. A plume is is how high the exhaust gases will rises above the discharge of the chimney. I have never heard of anyone wanting a low plume, you could have the flue gases coming in your fresh air intake. And the only why you are going to have a high plume is to put and Exhaust-o-vent on top of the chimney not on the bottom. I really don't think you are going to be able to get around a new liner.

Now if you changed to a different boiler and went to multiple boilers. You might be able to vent them out the side of the building like in an alley. But like I have said you need to check with your local code. I would really be surprised if the city will let you do that downtown.

Why reline the chimney?

Hi, HLH!

I don't have any direct bearing on this blog in my own background, so I asked one of my buddies who is a sheet metal man who formerly held a gas licence to give me his thoughts.

He asked what the fuel was, what the exhaust temp is, how old the building is, and the construction type of the walls to determine flammability. He thought the idea of using the existing chimney needed more thought, since the vent even with a single walled chimney might be enough, depending on the nature of the vent.

He mentioned a couple of vent types to me, but since I know nothing about the subject, I don't remember them, sorry. He did say that the Exhaustco equipment has changed a great deal over time.

He didn't think the effect of the exhaust plume on the neighbours was as important as I thought it was, because I was thinking in terms of a possible flame out or breakdown. But he assured me that all those considerations were inherent in the modern equipment.

I told him that because the walls of the double boiler were stainless that I thought the fuel would be natural gas, since stainless resists combination with the sulphur content of the exhaust.

I tried to entice him to respond directly, but he's in the process of moving and has just packed up the computer for temporary storage, so no go.

However, some of those considerations might be relevant to assisting you to find answers. Good hunting!

Mark

I don't know why you think fruit will be coming out of the flue, but a double wall stack requirement indicates a high efficiency (condensing) boiler. This will give you a great deal of vapor exhaust, but very little hydrocarbons. What kind of PLUME are you trying to avoid?

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A double wall flue is required because of several factor. One is temperature, the air gap is used as an insulator. The other is the flue gas can be very corrosive and will over time eat away a galvanized inner liner so they use SS. As someone else mentioned these may be high efficiency condensing boilers and these boilers require a special SS liner called AL27. And in most commercial boilers a double wall positive pressure flue is required. That is because the discharge gases out of the boiler are fan assisted, which pressurizes the flue. Those are the reasons why you would need to reline the existing chimney.

Liners are Code in most areas. I can't imagine what regions would not require it, maybe the people are fire-proof.

In our neck of the woods if the chimney is dangerous we remove it and replace with a flue

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