Joined on April 28, 2007
Last Post on May 5, 2007
@ May 5, 2007 11:04 AM in Engineering Help - DFDan, the first thing I see is using 2-pipe in a humid climate. The only people that love 2-pipe systems are owners at budget time. Even Jesus hates 2-pipe I am told. :) There are significant days when it is cool enough to require heat in the AM and later in the day it is time to cool/dehumidify but not enough time for the system to respond. This affects both the fan coil units (FCU's) but especially the Air Handling Unit (AHU). I would recommend creating a 4-pipe system -at the very least for the AHU. That I see as the largest contributor but also the largest potential agent to help you on the humidity side. If you extend the piping and replace FCU's or add HW coils, at least the HW portion you would install is the smaller of the two, CHW sizing being inherent in the system now. Keep in mind that the OA system is likely the largest agent of dehumidification. FCU's I consider mostly sensible coolers. If the AHU is not in a ready-to-cool mode, humidity control is an almost immediate casualty. Depending on the psychrometrics, you may have to cool that air to 52 degrees or more to give you some margin to absorb space gains. (Mind you I know nothing about this building or function.) Another detriment I have found is pipe corrosion, especially if the operators want to save a few dollars by raising the CHW temperature. Dehumidification is lost but the piping, even if insulated, is still way below the now increased dewpoint. Peel back some insulation and see. I am now replacing all iron pipe in a 1970-vintage school with similar circumstances. Even 1994-95 vintage replaced pipe is being replaces. Go to the cause. What is the big picture if you could say? 100% OA, if for make-up air for small offices served by fan coil rooms is one thing. A wholesale repair shop with lots of exhaust is another. Heat recovery, specifically energy recovery is the simple possibility if the return air is not too filthy. I wish I was close-by. I would love to walk it through with you. I know Fort Belvoir. "Through These Doors Pass the Best Damn Engineers in the World." OK, they shopped this one out. :) I did not say that.
@ May 5, 2007 8:57 AM in Why can't they make an erasure that works !!!:) Thus marinating in perpetual ignorance, as my dad would say. The real answer? Rubber is expensive and latex causes allergies in too many people. Now they use a vinyl or other synthetic substitute material I believe. The erasers take on a burnishing (outer shiny finish) which makes erasing your tracks an exercise in public humiliation. I imagine some kid chewed the eraser (NEVER happened in our day did it? Like during a test??? :) Kid probably went into anaphylactic shock, swelled up like a day care center field trip at Planter's Peanut Land and then lawyers got involved. Thank a lawyer but cross your fingers when you do. Plumbers add value to society.
@ May 5, 2007 8:51 AM in pipe sizeFor a loop half as long and with a similar load, 1-1/4" would be my choice, but I agree with Dan, that 85 feet may be a tad long. The other factor is, how many radiator feed sets? If you have only five large ones that is one thing. 65 one-footers makes for a challenge :P Also, 65 LF of baseboard versus that 75 MBH boiler, I suspect some form of decoupling and reset would be of benefit. Carpe' Opportunitas
@ May 5, 2007 8:46 AM in Assessing a Two-Pipe Steam SystemChristian- what can I say? Thank you for the (as usual) thorough, erudite and Eglidite treatise! What I love about this place is that, while I was well steeped in steam early-on, the residential applications still hold enough mystery to keep it all interesting. Ever learning every day. With your post above, might I take the weekend off? :) I had a feeling that the mystery vent had a vacuum function in a prior life while now standing as a relic in obsolescence. Still, a vent is needed and while this may serve the function, what vent brand or model might you recommend in the spirit of renewing critical components? Ever Grateful for your Brain, Brad
@ May 4, 2007 6:33 PM in White caulking material?to the Insul-Coustic material (which remains pliable). Comes in caulking gun cartridges and plastic buckets. Sticks to everything....Most of the other cements dry with a flat finish, such as PorterLag.
@ May 4, 2007 5:20 PM in White caulking material?most likely. Here is what is in my specifications as manufacturers to check out: 1) Benjamin-Foster (BF) 2) Chicago Mastic (CM) 3) Insul-Coustic (IC) 4) 3M 5) St. Clair Rubber (SCR) 6) Vimasco (V) 7) Baldwin-Ehret-Hill (BEH) 8) H.K. Porter (HKP)
@ May 4, 2007 4:17 PM in Assessing a Two-Pipe Steam SystemThe B dimension is, surprisingly... 56 inches. I have a suspicion to be confirmed that Ed Wallace might have done this install some years ago. The devices seemed like a vent (air eliminator by another name would not smell anything like a rose). I suspect that it might be a Hoffman Receiver Vent as depicted in Figure 56 (Page 266) of The Lost Art. I will have to look at it with regard to the peripheral piping. Some more detail would help, maybe a new set of eyes. I will stroll the library too. Does anyone have an explanation of the actual operation? I suspect it has been abandoned from original function for some years, if it is a Hoffman Receiver Vent. The returns are at most one-inch from each end of this end of row house. Seems that a Gorton #2 if not a #1 would be plenty but I have to make sure that the device is nothing more than a vent. A device that ornate for such a mundane purpose has me wondering. The top has what seems like the body of an egg petcock without the lever. The top seems to have a ball bearing which can be depressed with my finger (or else my fingertip gave so easily), so I suspect it has a vacuum breaker function. Hence, my caution about wholesale replacement. Adjacent to this is a vertical plugged pipe which connects to the riser (atop which is the vent discussed). This vertical 3/4" pipe connects with a tee just above the water line in that riser and rises to about eight inches below the elevation of the vent. There is a plug there now, so I suspect an air vent at one time. See the attached photo should it jog something. While the system has been set to run at 0.50 cut-in and an apparent 1.5 cut-out, I am going to recommend as an alternate a Vaportstat and really fine gauge to supplement the code-gauge. Insulation of all piping to be sure, replace trap guts and adding a trap on the one radiator without one... pretty straight-forward stuff. Thanks for any insights!
@ May 4, 2007 2:57 PM in Assessing a Two-Pipe Steam SystemI would have ballparked about 5 EDR per section. They are rather elegant! What is the relationship between American Radiator Company (which was cast on the top of the end section) and Peerless (cast on the lower bosses) if you know? Just curious. I would imagine Peerless either did the casting for them or were distributing them. Thanks again! Brad p.s. small world in that the Owner has a harvard.edu address also. :)
@ May 2, 2007 5:18 AM in VisioHave no inter-relation that I know of. Different command structure. One might be able to import a HydroniCAD object into AutoCAD (using OLE) but I have never tried it.
@ May 1, 2007 9:03 PM in Steam valvesthe zoning is disparate enough in temperature over longer periods of time, I see the only way to control this system is at a probably much higher pressure than it needs to run without the valves. This will cost more fuel of course. The setup would have a pressuretrol maintain X pressure. As valves close down this will satisfy sooner and of course cause short cycling. Too many variables without knowing more details but that is my simple view. If control can be had at the radiator level (thinking TRV's) there will be less wholesale turndown and better control room to room. That to me is a better approach. The valves- one never knows if they were original to what might have been a sound installation. I suspect that they were an add-on. Just because it was does not make it right... I would stand back and take a look at the system as a whole. Make it work as originally intended. The hardest job we sometimes have is stopping people who want to hurt themselves. :)
@ May 1, 2007 8:25 PM in Steam valvesIf one-pipe steam, I would avoid that. If two-pipe single-zone, I would still avoid that without knowing more. The place I would be most likely to install such valves and controls is when I have a source of ready on-call steam such as utility steam. If as you say the system is working OK except for the kitchen, why not solve that and be done with it. Graveyard is full of dead heroes.
@ May 1, 2007 6:59 PM in VisioWith a fair selection of blocks (objects). Done some time ago in 2003 to illustrate zoning possibilities with a Monitor MZ
@ April 30, 2007 8:33 PM in Buffer tankI suppose it cannot hurt, but that was not really your question. Personally, I do not see buffer tanks as an absolute "must-have". Rather, they are installed to help mitigate a problem. If the problem is short-cycling, there is an advantage. I guess hearing my dad's voice, saying "if it's not broken, don't fix it" applies here.
@ April 30, 2007 7:30 PM in Performance of hyrdonic baseboardWhen you remove the front panel it is like taking off the side of your chimney and expecting to maintain draft. You need to channel the air through the element, not bounce off it. If you look at fin tube charts, particularly those in the commercial line (which have taller enclosures, such as 12", 18", 22" and taller), a given element will have increased output with increased height, all other things being equal. The taller chimney forces more air over the element, simply.
@ April 29, 2007 9:36 PM in Valves I acquired with a new house.on e-Bay as you are thinking and see what they are worth. To me, Neles-Jamesbury valves are about as good as they get in the commercial market. Yet, on e-Bay, I bought a dozen 1" MPT ball valves, a 1-1/4" and 1-1/2" ball valve for about $30 plus shipping. The 1" valves I have seen for upwards of $25 retail. Such a deal. Your Sharpe 2" stainless steel valves have probably the most intrinsic value. The other valves, Jamesbury aside, would go for between $10-$15 new, in that range. Expect to get much less. As Jim said, they are worth the highest price people will pay. Try it anyway and good luck.
@ April 29, 2007 12:04 PM in How necessary is ERV for residence?Right-o on my setup. The first question you have to ask yourself is, how tight is your envelope? Insulation notwithstanding, how much infiltration do you have? If it is sealed enough that a blower door test reveals less than 0.50 ACH per hour, you may have a need. More than that is a "want", unless your exhaust hours of operation are most of the day. Typically an ERV or HRV is sized for about 0.35 ACH to give you an idea of the scale of things. If your ACH is above 0.50 by a good deal and unless there is another parallel need (as in my case) it is a "want". As to HRV or an ERV, here is the scoop: How many hours of heating and how many of central cooling, coupled with how many hours of below-freezing weather do you have? Each ERV manufacturer uses a different technology. The best ERV's (Energy Recovery Ventilator) is a 4 angstrom molecular sieve type. These can be coated paper or plastic cores or made of a solid desiccant material. These recover both sensible and latent heat. If you humidify in winter and dehumidify in summer, this is the way to go. Typically, the colder the climate the more likely it is that you will go to an HRV (Heat Recovery Ventilator) which is sensible-recovery only. South of the Mason-Dixon line, ERV's are more common. In the Yukon, HRV's rule. In my case it was a matter of recovering what little heat the bathroom exhaust would lose coupled with the need to supply OA to the interior laundry room for combustion air. The hours of operation say that the 70% efficient unit would be just fine. I just specified three (3) 95% double-core HRV's for a school to ventilate interior corridors that never had ventilation (since 1956!). The HRV's made far more sense as there is no cooling.
@ April 28, 2007 5:16 PM in All fuel ventchimney system especially in that it will be outside the heated envelope. All of those cold starts, you want to maintain your stack temperature. EDIT: To be clear, the type I am referring to has an inner wall, 2" insulation, an outer wall and an annular 1" air space. Heat build-up is secondary and the triple wall will minimize that. Check the ratings. I believe (from memory) that the surface temperature should be no more than 95 degrees with 400 degrees (or some other specific) flue gas temperature.
@ April 28, 2007 2:44 PM in Panel RadsHe did say "Jaccuzzi". I figured a properly sized indirect can serve that. If only once a week then a tankless might make sense. At least the standby losses are not much. I find the recovery superb but as you are right to mention (or infer by your pointing it out), it may tax the boiler and work against the heating side. No jab taken on the preference of radiators, Chris. It is all subjective. I like their "heft" and as for the fence look, I have a variety from vertical panels to the horizontals, the "bike rack" type too. All personal preference.
@ April 28, 2007 2:09 PM in Panel RadsI am partial to Runtal. They may cost more than the Veha, Buderus and Myson stamped metal lines but I like the look and variety better, including the towel warmers. Certainly if you are only installing only one, I would spring for one you like the best. Nothing says you cannot use a towel warmer AND a convector. I have both plus radiant floor in my 60 SF master bathroom. As for DHW? Indirect. Tankless has it's place but I have always encountered issues in talking to users (including family members). Issues such as waiting for hot water if too far away, cooling along the way (distant runs of existing non-insulated piping) and fluctuations in temperature. Flow rate is the limitation, not volume. Filling a tub is one thing, simultaneous showers, tub filling, laundry and dishwasher can find you. Indirects have always served me well.
@ April 28, 2007 1:54 PM in How do new Burnham cast iron rads measure up?Subjective as the term is, they have value. They are, IMHO, beautiful. Can you get salvaged CI? Sure you can and the price from a knowing seller (who has to handle them, clean and test them then stand by them) may not be a whole lot less. Either way, you should be fine. If I had my druthers and wanted a first class installation, I would go with the newer line of classic Burnham CI radiators and have them powder coated. American made too.
@ April 28, 2007 8:45 AM in heatingCall a professional. This is not a do-it-yourself operation and any small amount of advice given could mushroom rapidly into a dangerous condition, far worse than being uncomfortable. Just a hunch so forgive me if I am off on saying so, but if it is a matter of not being able to afford the work, call a pro anyway and explain the situation. There may be city or county or public utility agencies that can help. The good news is, it is not the dead of winter. Bottom line- do not attempt anything yourself unless you know exactly what you are doing.