Joined on December 20, 2004
Last Post on March 9, 2014
@ March 9, 2014 9:36 PM in New FlueI would ask the chimney contractor to perform a Level II inspection, which is a comprehensive top to bottom inspection. That will determine if the chimney is suitable for continued use and what repairs if any are warranted. Since there was material at the base of the chimney that means that material is no longer where it started up in the flue, hence your flue can no longer perform its intended function. You will need a liner. The liner must be suitable for the class of service. Since this chimney once served oil, any liner must be 316 alloy of stainless steel or better. Most liners are 316Ti these days with a pinch of titanium thrown in. Get one with a transferrable lifetime warranty btw.
The liner must be at least the size of the appliance collar. In addition, corrugated liners must be de-rated for corrugation (20%) plus an additional 20% for any offsets.
The vent connector galvanized steel pipe gauge thickness is determined by NFPA 211, which calls for 26 ga. below 6", 24 ga. 6-10", 22 ga. for 10-16" then 16 ga.above 16". You can drop one ga. size smaller if using stainless steel. In other words, for a 6" flue, you can use a 24 ga. galv. or 26 ga. ss connector. Follow 211 for pitch, connections, support, etc. No flat runs--min. 1/4" per foot slope upwards to the chimney.
You can not use B-vent inside a chimney that once burned oil--it will eat it up.
The barometric damper should be located close to the appliance but leave at least 2 duct diameters from the appliance collar and any ells to you can drill your test hole for combustion analysis. I try to locate them on the vertical rise if possible. If you must install it on the horizontal leg, you have to reposition the adjusting weight to the left side of on Field RC dampers. Bull head tees for baros. are not recommended for oil. See the diagram from Field Controls for damper placment.
@ March 5, 2014 7:28 PM in Pressure Relief Valves on Expansion TanksWhile ME is partially correct, your local AHJ can NOT just indiscriminately require whatever he feels like. They are code ENFORCERS--not code legislators. Every jurisdiction must have a mechanism for implementing LEGAL code change. This is typically the submission of a proposed change with supporting data and arguments/ logic. At some point, three public hearings are held for stakeholders and citizens to voice their concerns. Then the local governing body votes it into law or rejects it. Only once it has been voted into law as a local ordinance does your AHJ have the power to enforce it.
Even that process has another level of review: The International Code Council. Where the I-codes have been legally adopted, local ordinances that go above and beyond the current I-codes can be reviewed and in most cases, overturned. This happened in Pa where right after we adopted the ICC suite in 2004, some jurisdictions adopted ordinances such as residential fire sprinklers. The builders went to the ICC and have 14 of 14 cases overturned.
An AHJ has the power to rule only where there is no applicable code. Even there, he is charged with relying, whenever possible, on reports, listings, or other credible data. In the case of the expansion tanks requiring pressure relief valves, the AHJ would need to show case studies where tanks failed during unfriendly fires that resulted in personal injuries or damage to the structure significantly over and above that which would have occurred anyway. He would have to present test data showing what sort of pressures these tanks could be exposed to and what form of relief would be warranted. For instance, do you install just a pressure relief valve or a temperature/ pressure relief valve and what ratings? TPR valve stems must be fully submersed in the liquid so how are you going to do that in the piping downstream of an isolation valve. Also, what is the incidence rate of such a tank being left isolated as opposed to online? If left isolated, the boiler's pressure relief will likely discharge during heating cycles letting you know something's up and call for qualified service.
I find this a pretty rare hazard and think its just paranoia. Often, AHJs will read of one isolated incident then make a name for themselves locally by instituting changes based upon imperfect information. Most of the stories about losses are just heresay and not evidence-based from litigated cases. Also, if this was such a hazard, believe me the CPSC, ICC, NFPA, etc. would be all over this.
@ February 25, 2014 6:39 PM in Has anyone ever heard of this?When you have engineered joists and still see shrinkage, its usually more the mudsills the rim joists are sitting on or interior columns on poor footings. If the floor is still level, then its probably not the mudsills. Engineered joists shrink very little in my experience and when they do, the similar components shrink uniformly. Did he measure the thickness of each plate?
@ February 24, 2014 9:03 PM in How many of you carryI carried a Scott Bacharach personal CO alarm set to alert at 35ppm for about 12 years. It has been replaced by a CO Angel set to 35 as well. They have gone off so many times I couldn't count. They have drawn a lot of inquiries from homeowners which led to sales of low level CO monitors and repairs. They gained respect from mechanical building inspectors, fire marshals, etc.
I'm a retired paramedic and have transported quite a number of CO victims. I've had CO poisoning myself back when I worked for someone else.
Personally, I think its irresponsible to send any employee into any buildings without a personal CO alarm. Note that in the recent Long Island incident, three paramedics had to be treated as well.
A local EMS responded to a call at a grocery store that ended up transporting 31 to the ER. They discovered the reason granny zonked out at the bakery counter when their personal CO alarm sounded. BTW, their dept. responded wearing SCBA and screened everyone in the store with Masimo Rad57 CO pulse oximetry units and transported anyone with a COHb of 5% or higher. BTW, 6 were transported from the adjoining drugstore.
Anyone entering a crawlspace should wear a 4 in one confined space alarm: LEL, O2, CO, H2S
@ February 23, 2014 9:22 AM in another case for pesonal protectionhttp://newyork.cbslocal.com/2014/02/22/1-dead-dozens-rushed-to-area-hospitals-after-carbon-monoxide-leak-at-long-island-mall/
Sad case but it hopefully makes you aware that almost NO buildings
in the US, residential or commercial, have adequate CO protection, are
not required to have periodic maintenance that includes CO testing with a
professional combustion analyzer, no requirement or standard for the
techs using such equipment, no requirement for professional periodic inspection
by qualified inspectors of the venting (because HVAC techs are not so
qualified--trust me!), and the UL listing for carbon monoxide alarms
prevents alarms from sounding until you have CO poisoning (10%
carboxyhemoglobin level). Those alarms are designed to protect you from
CO death--Not from CO poisoning and apparently there were none at this
So, what can you an I do? I wear my own personal
CO alarm, which alerts at 35 parts per million after 60 seconds. It is
an electrochemical sensor and very accurate. I take it everywhere. Note
many of the victims in this case were cops and first responders. We walk
into toxic atmospheres all the time and don't know it. We drive in
traffic, fly in planes, stay in hotels or friends homes, shop at stores,
are admitted into hospitals, etc. but there is only one place where you
will routinely find adequate CO monitoring--parking garages. They are
required to have low level sensing linked to alarms and exhaust fans
depending upon the level. Don't be a victim--get your own personal
protection for everyone one you know and wear it or put it in your
pocketbook. Humans cannot detect CO. Very preventable. BTW, the manager
may have died from the trauma of falling down stairs or even had an MI
We had a similar incident at a local grocery
store where about 30 were transported for treatment. The local EMS had a
personal alarm that sounded when they responded to an elderly lady
collapsed at the bakery. 6 patients were from the attached drugstore
next door. 6 months later, it happened again in the same store from the
same oven! Don't assume anything!
@ February 22, 2014 10:01 PM in Tim; New IFGC QuestionWashington Suburban Sanitary Commission. They are the AHJs from western MD down around DC. I've had many a "discussion" with their inspectors.
I'm not sure what the OP is referring to but I'm thinking its one of those chimney kits that acts like an axial draft hood on 80% furnaces.
As far as the requirement to reline, you must inspect the chimney when replacing equipment. The Std. for inspecting chimneys is NFPA 211. A proper level II inspection will undoubtedly reveal the chimney is no longer suitable for continued use for the intended purpose and therefore must be relined with a listed liner and in accordance with the IFGC, which back references 211 for heating chimneys and vents.
Basically, you have to prove a chimney does NOT need to be relined. You'll find a suitable chimney maybe one in ten thousand. Code compliant chimneys do not exist in the wild.
You reline when the flue is oversized, eroded or improperly constructed such as gaps between flue tiles. You also reline to size the flue to the appliance for performance. You reline exterior chimneys that run cold and don't draft reliably. Relining does not overcome structurally unsound chimneys, short chimneys or other major structural defects.
@ December 15, 2013 12:07 AM in On an atmospheric boilerSorry to steal your thunder Timmie. Please feel free to expand on any of these concepts. I'll chill and let some other people comment. You are da' man always.
@ December 14, 2013 5:03 PM in Second shutoff for boiler on stairs?Required for oil under NFPA 31--not required for gas.
@ December 14, 2013 3:52 PM in On an atmospheric boilerIn addition to the points Timmie made, let me offer these additional concerns:
High primary aeration with a low manifold pressure may result in flashback
High primary aeration with a high manifold pressure may result in flame lift-off
Low primary aeration with moderate to high manifold pressure may result in yellow tipping.
The higher the primary aeration, the greater the velocity of air being entrained at the venturi and not just volume. Therefore, subtle increments can have a significant impact. This can be beneficial such as with LP where we need that turbo-boost to help shoot the fuel/ air mixture down the mixing tube towards the burner ports and create turbulence for better mixing.
One side negative of primary aeration is the propensity to cause poor combustion from the recirculation of combustion products, which is why we add in secondary air. This recirculation is mainly seen on a cold start, which can be seen on a combustion analyzer. Once secondary aeration is established, there is better flow up the stack and removal of combustion products. Too much secondary air can cool the flames resulting in poor combustion, which is one of the drawbacks of high excess air. Each fuel gas has its own specific properties in these regards, which is why it can be very difficult in some units to get them to behave when performing a fuel conversion.
With regards to flame speed as Timmie pointed out, the flame front moves faster at higher air/ fuel ratios. This is all very specifically calculated, engineered and tested with burner designs, venting, etc. One example of flame speed is on an Oxygen Depletion Sensor safety pilot of all ventfree appliances. As the ambient O2 drops to 18.5% the pilot flame appears to advance out past the tip of the thermocouple causing the pilot to dropout. This is because the flame is burning slower back towards the pilot burner thus creating the 'gap'. Now, if you have too much air, the flames can race back so fast that, depending upon burner design, port loading and esp. temperature of the burners, the flame front can run down through the burner causing flashback or extinction popping.A narrow mixer tube and smaller burner ports can increase primary aeration without flashback or extinction popping.
Lint can stop burner ports causing major changes in aeration and fuel/ air mixing so cleaning burners is very important to good combustion. Engineers have to figure what method they will use to eradicate lint from the burners such as incineration, filtration, re-directed airflows, etc.
It will be interesting to see the effects of high Wobbe Index fuels with time. The studies thus far indicate no major concerns but those were conducted by agencies with close ties to the fuel providers and government so I don't trust them one bit. I think you and I will inherit a mess of problems if LNG becomes more prevalent either straight in or mixed with existing stocks of pipeline NG for peak shaving during high demand periods.
@ December 13, 2013 1:36 PM in Boiler Pressure Spike while under heatUndersized or failed exp tank. If not on an isolation valve, install one so the pressure can be tested with it isolated from the system without dropping the system. If you get water out of the Schrader valve, the diaphragm is blown and the tank needs to be replaced. The charge should equal the operating pressure of the boiler.
Failed feed valve. Isolate the valve to test this. If bad, clean strainer first.
Bad PRV. Test annually and replace every 3 yrs or as needed.
Yes, leak from hot water coil but this would be constant as would bad feed valve. PRV release on firing generally from undersized, waterlogged or otherwise inadequate exp. tank.
@ December 13, 2013 1:27 PM in What is the definition of2009 IRC G2403 General Definitions
Air, Makeup. Air that is provided to replace air being exhausted.
[me] This includes combustion, dilution and excess air through combustion systems but it also includes air exhausted by fans such as kitchen hoods, dryers and fart fans in bathrooms. There are several specific places in the code, such as M1503.3, which require MUA. This this case, it is referring to exhaust hoods >400 cfm requiring dedicated powered MUA interlocked with a damper and sized to equal the exhaust.
@ December 13, 2013 1:17 PM in What doesKnown Air Infiltration Rate for calculating MUA requirements. IRC G2407.5.2
Used only when ACH 0.40 or less. Otherwise, use Std. Method.
@ December 11, 2013 12:16 PM in 5 Die of Carbon Monoxide PoisingI has never been proven scientifically that CO has any odor. You may, however, smell aldehydes, which may or may not accompany it. With fuel gases, they typically do not have an odor of their own so producers are required to add various types of odorants depending upon the application. Not everyone is sensitive to these odorants and one person might be sensitive to one odorant but not another. You couldn't tell which stink gas was used without a gas chromatograph and someone who knows how to use and read it.
Would be interested to see if there was a UL listed CO alarm present in that house.
@ December 10, 2013 10:28 AM in This is interestingWell, I agree John. NCI only sells to contractors who have taken day one of their Cert. course and require them to sign a paper saying they will personally install each one and not sell cash & carry. George Kerr sells them to anyone off his CO Experts website (his price has gone waaaaay up!). I heard he was going to market his monitors through Graingers but I don't see them on their website.
The gubbermint introduced legislation (HR1796, which passed the House) to outlaw the manufacture, sale or distribution of unlisted CO alarms. That's why these are called "monitors". The big alarm mfrs. are in bed with the fire chiefs, IFSTA, etc. who don't want low level accurate CO alarms. You see, fire depts. are the ones typically charged with emergency response to CO alarms and it eats into their budgets. It's always follow the money. The bldg. codes all refer to UL2034/ 2075 alarms. Fine, install the junk then install a low level monitor that's going to protect you from CO poisoning. Listed alarms are designed to alert only once you already have CO poisoning-5% COHb level. They are for acute catastrophic exposures but do nothing to protect day in, day out against lower levels of CO poisoning. The UL listed junk usually state on their own packaging you may need "additional protection" for infants, elderly or those with certain medical conditions. Then the gubbermint outlaws that additional protection!
@ December 8, 2013 5:54 PM in Removing furnace from gas ventAccording to the 7x rule, you can leave an appliance with a 3" vent collar vented into a 7" but not 8" vent. However, if it is a 4" collar, you can vent that into a 10.5" vent. Doesn't make it a great idea and certainly doesn't guarantee performance but under the gas code, it is acceptable if all else is.
Now, venting a 40mbh WH into a cold exterior 8" vent even with 4" vent connector is a recipe for condensation and/ or backdrafting.
Consider replacing it with a power vented WH out the side and be done with it.
@ December 5, 2013 12:46 AM in Pressure relief valveVerify the correct size for your thermal expansion tank. Undersized tank can result in overpressure and discharge.
@ November 29, 2013 10:00 AM in Gas Conversion/ Deteriorating Smoke PipeIf any portion of the chimney is exposed to the outdoors below the roofline, it is treated by the codes as an 'exterior' chimney. When switching fuels, you should have had a Level II chimney inspection, which undoubtedly would have called for a listed chimney liner and replace whatever connector is going bad. Combustion analysis would then tell the tech what he needs to tweak the firing. He may be able to set the burner for a 3-4 min. post-purge to correct condensation in the connector but if its doing that there, what's happening in the chimney?
If it is unlined, it must be lined at once. If it has an old tile liner a level II will show failures most likely but you also have to consider a cold stack and being oversized in most cases. The listed liner will take care of most of these issues as long as its properly sized.
@ November 29, 2013 9:54 AM in Carbon Monoxide Issues - HELP!CO2 is what you are exhaling. You want an unlisted low level CO monitor-not an alarm. There are currently only two I'm aware of available in the US:
The NSI is available only through certified contractors and they are currently backordered into Jan.
George has raised the cost of the CO Experts recently so check his web site for pricing and discounts.
NCI uses 100ppm as the max. an appliance can be emitting into the flue gases. They do not allow more than 30ppm in the room based upon various national stds.
Listed CO alarms are designed to warn only against CO death--not just poisoning. The fact you had a CO alarm alert means you were poisoned. Most any fire marshal would red tag this installation and shut it down or force you out of this house.
@ November 29, 2013 1:27 AM in Carbon Monoxide Issues - HELP!A CO detector or alarm listed to UL 2034 is junk that will not protect you against CO poisoning. It is designed to alert only once you have a carboxyhemoglobin level of 5%. If your alarms have alerted then by definition, you have already had CO poisoning.
Get a pro in there who is NCI certified in CO. Also, you cannot vent under positive vent pressure unless the venting is listed to UL 1738. No homemade junk with joints gooped with red RTV silicone.
Do Not operate this appliance until corrected.
@ November 28, 2013 12:40 PM in big nipple trays?http://www.biggerbras.com/m-large-cup-bras.shtml
Ok, I'll behave. Take a board and screw onto it wooden dowels spaced sufficiently for about 6 pipe diameters plus wiggle room.
Begin stacking nipples over each dowel by size. When you get to the last one, drill a hole and insert a long framing nail or brazing rod sufficient to retain the nipples with one end peened or bent and the other with a push on spring nut to retain the nail/ rod. You can drill holes down the dowel so that as you remove nipples, you can lower the retaining pin. If you put an eye bolt or handle on the endgrain of the board, you can then mount them up on a wall or hook with the nipples standing out.
@ November 24, 2013 12:35 PM in 80% gas furnaceClass 'A' chimney is considered "all fuel". Actually, it must be listed to UL 103HT in the US to meet that class as solid fuel requires a 2,100f rating whereas regular factory chimney carries a 1,700F rating. You are allowed to increase a gas vent up to 7x. With a 4" vent at a cross-sectional area of 12.56 " square, you could legally vent that appliance into a 10.5" vent if everything else is ok.
the sizing charts in the gas codes, which were provided by GAMA, start with a 12" rise off the appliance collar. While it may be allowed, it certainly is not a good idea. Spence was correct in his info. A single walled connector for gas carries a 6" clearance to combustibles. This work is best left up to a pro.
@ November 21, 2013 12:52 AM in Combustion airThe code does allow for "engineered" options. Putting a powered MUA unit in is one version. He can install an inline duct boosting fan run off a rheostat. Dial it in to the lowest speed that gets the job done as proven by combustion analysis. You can slave it off the primary on a call for heat. Note that a cold intake pipe will sweat and condense. If it is not stainless steel or aluminum, it will rot out. When not in use, it can have a modest backdraft damper that swings open when the fan energizes or you can wire in an automatic damper. If you duct it down into a large bucket that will tend to minimize cold air infiltration a little bit at standby.