Protection against spillage

Unknown

spill switch all the same thing and flame roll out switches. How many of you add them to existing equipment not so equipped? I prefer the manual reset blocked vent switch because it will create a service call (do not show the customer how to reset it).

How many have ever heard of Star-Kap chimney caps designed to prevent downdrafts & I have been looking at some posts about varmits getting into chimneys and flues. The Star Kap will prevent this. This will minimize the effects of downdraft and formation of Carbon Monoxide.

Now if we can get the gas heating world to wake up add to that mix a Barometric Damper and we are on our way to eliminating Carbon Monoxide problems. How many know what the "curtain effect is". Hint, Hint the draft hood can cause this. The Utica boiler I posted about recently had this problem.

These devices along with proper testing, diagnosis, testing and then adjusting and testing again can increase efficiency and decrease CO drastically.

Now this is not the whole story but it is a start.

We can post all of these CO incidents and that is great, but now let us begin to talk about some procedures to prevent problems. In order to properly apply, adjust and test you need training. Get to the NCI classes but before you attend Jim's classes you need to see me and get the basics down, that way when Jim takes you up another step it will be easier to understand. With out basic fundamentals and troubleshooting procedures you will walk right by the problem and never see what is wrong. I find techs are amazed when I walk into a boiler or furnace room with no tools and begin to tell them what is wrong, much of it is visual and after years of spending time in basements you become very observant.

Mark Hunt

One right after the other


That would be a one, two punch!!

These FVIR water heaters will expose some folks to "curtain effect".

Mark H

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Unknown

\"Curtain Effect\"

It is often the case with Draft Hoods that are part of the fixed package with design gas systems that they cannot regulate the flow of air into the flue and or through the appliance. This can result in poor combustion, which in turn can contribute to CO emissions. In some cases the "fixed" draft hood allows too much "dilution air" which in turn produces the "curtain effect". The curtain effect exists when a higher volume and velocity of cooler room air (dilution air) enters the fixed opening on the draft hood and creates a restriction to the flow of hot combustion gases out of the combustion chamber. This in turn can cause the products of combustion to spill back into the building.

It has been my experience that using a double swing barometric (required for gas) I can regulate that flow of dilution air and control draft accurately. This in turn will maintain a consistent air flow through the equipment and prevent the "curtain effect" combustion which also improves efficiency. The down side of the use of a barometric on design equipment is that it is not approved by manufacturers and code enforcement.

The issue now becomes do we play by the rules or do we step out side the normal way of doing things and improve operation, efficency and safety? I try to the best of my ability to play by the rules, but it can be frustrating. It means that many times equipment gets "red tagged" when the addition of a baromteric and a special cap for the flue could have allowed the equipment to operate for many more years.

I feel each person must operate by their own convictions. Liability becomes a big factor when we change the design of a piece of equipment. It is interesting when you look at the code and it states" A venting system shall be designed and constructed so as to develop a positive flow adequate to convey flue or vent gases to the outdoor atmosphere."

It goes on further down in the section titled "obstructions" and states the following shall not be considered OBSTRUCTIONS:

1. Draft regulators and safety controls specifically listed for installation in venting systems and installed in accordance with the terms of their listings.

2. Approved draft regulators and safety controls that are designed and installed in accordance with approved engineering methods.

Mad Dog

I add them in when I can sell them

to the ho. I'll put them on water heaters that are used for space heating too. MD

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[Deleted User]

i use them

and love them..i have one install that i also left the draft hood in place because the old coal chimney was drafting so viciously that i put a barometric in the flue and it acted to relieve some of the draft so that i was actually able to achieve -.02 thru the boiler..and now the o2 and co readings are where they should be..before the o2 was real high and the efficiency was real low..

jim sokolovic

Well explained, Timmie...

That's how issues get resolved, hopefully. But if there were no fixed opening draft hood provided, then we have to rely on each and every installer to adjust the barometric properly. We see how few do this on oil, so most of the time it results in a sooting condition, at worst. With the current level of trained personnel out there, would there be more or less CO problems on gas-fired units, if only an adjustment required draft control were implemented?

Unknown

Jim based on my experience

with most installers and service techs they would need training on adjusting and setting up furnaces and boilers with barometrics. Having said that the learning curve for everything eventually levels off. We have had a lot of new technology in the past few years and slowly but surely people are getting on board.

To answer your question I think initially there may be a few more incidents of CO. I would prefer seeing the option available to those who choose to use barometerics as a problem solving technique. The manufacturers could include some guidelines in their instructions to assist in properly setting up equipment using a barometric. It would work pretty well with those who use a draft hood seperate from the furnace or boiler. Those who build the draft hood into equipment would have more of a problem.

jim sokolovic

Spill switch with barometric damper...

With the draft hoods I have seen, the spill switch is factory mounted, or a definitive mounting location is provided, which is tested and certified. Can you still mount a spill switch somewhere, in conjunction with the barometric damper - when you convert the equipment to this?

Unknown

There are instructions from Field

on proper mounting of Blocked Vent Switch on Barometrics.

Unknown

Blocked Vent Switch

should be added on every job as a safety to shut off in the event of spillage. It is just another way of preventing problems with Carbon Monoxide. Do not use the auto reset use the manual reset and DO NOT SHOW THE CUSTOMER HOW TO RESET.