Security Seal Facebook Twitter GooglePlus Pinterest Newsletter Sign-up
The Wall
jerry scharf

jerry scharf

Joined on May 17, 2004

Last Post on March 13, 2005

Contact User

Recent Posts

« 1 2 3 4 5 6 7 8 ... 19 »

a TRV would be ideal

@ February 3, 2005 11:45 AM in adding a radiator / radiant heat to a hydro-air system?

Steve, I would set up a separate zone with a small circulator that ran continuously during the heating season. Then I would install a nice low mass panel radiator with a thermostatic radiator valve (TRV.) The TRV adjusts the amount of hot water allowed into the rad based on the current temperature. With the low mass of the panel rad and the TRV, when a blast of cold air comes in, the rad will heat up quickly, warm up the area and drop back to the idle state with no external action. I think you are fine running the rad with pex or pex-al-pex. Normally I would recommend outdoor reset with the panel rad/TRV setup, but it would not mix that well with the fan coils. You may need to do some fudging of the control system to add the constant circ, but maybe not. One warning: Once you do this, you may hate the heat in the rest of the house. :) jerry


@ February 3, 2005 11:28 AM in Natural gas flame and CO

Bob, thanks for the info. I had no idea about the difference in soot. How hard would it be to tell the difference in the field between the two types? There is often a "it's from candles" response to soot streaking from baseboard heaters. If you could tell the difference between types of soot in the field, it could really help this. Also, I'm interested in the aldahyde formation. How does it form, and what are the concequences? Do the levels here compare to the long term exposure problems often discussed in IAQ talks? jerry

It depends on where you live

@ February 1, 2005 11:22 AM in Oil or Gas; which is more economical,what is the truth?

Mark, You're trying to guess the average relative future price of often interrelated products, fuel oil and natureal gas. You get to look deep into your crystal ball and then take a WAG. As for the rest of what you said, if you have a cracked heat exchanger and are getting soot in the house, then you need to shut the furnace down RIGHT NOW!!! There is a myth that oil doesn't produce carbon monoxide. You don't want to be the one who finds out how wrong that is. It may not kill you, but the list of other exposure problems starting with permanent loss in mental capacity, heart and lung problems should scare you. If you are in the trade, go and take a course from NCI, Timmie or Firedragon and learn about combustion. It will open your eyes! jerry

You would be wrong

@ February 1, 2005 10:45 AM in Oil or Gas; which is more economical,what is the truth?

Fred, The risks of propane and natural gas are very different. Propane pools in explosive mixtures while methane (NG) does not. Both can produce explosions, but I'm much more careful with propane. Also, if you haven't figured out by now that CO can kill you whether you have NG, propane or oil, I'm not sure how much of the wall you read. You need to be just as careful with oil as anything else when setting up combustion and you still need something to measure the CO generated. jerry

laptop religion

@ February 1, 2005 10:33 AM in Laptop Computers

First, you have to decide which messiah you follow, Bill or Steve. It's sounding like Steve is out of the question. Then you have to decide whether you seek freedom or power. For the travel type that hate weight, I do like the centrino units. For the "desktop replacement" big boys, I like the athlon and P4 mobile chips. I am really fan of the AMD chips, but the differences don't really matter that much. I just got a centrino based system, which claims to be able to go coast to coast in an airplane on 1 battery. Given that all battery people lie, it will probably be more like 3 hours. That's still a whole lot better than the other power hogs. Mine comes in at 6 lbs, which is a couple pounds lighter than the big boys. Get a faster disk drive! The standard disk drive for a laptop is 4000 RPM. There are 5400 RMP disks out there, and they make a big differece in how the system performs. It will be a much bigger difference than an extra 10% of cpu speed. My eyes are tired, and I like the ability to use my laptop without reading glasses. This leaves the 15" XGA+ screenas the best choice. The bigger ones go to higher resolution so on both sides of the hump the print gets smaller and smaller. You should get at least 512MB RAM. Given your budget, I think that is all you can afford. Laptop RAM still has a price premium over desk units. DVD-RWs are nice, but cost ebough more to put them out of your budget. At least get a CD-RW for backups, and most people want a DVD as well. Wireless is cool, but you have to understand how to secure your system before this is safe. Not sure how easy it will be to hit the price target if you factor the MS Office cost. If that's not part of the $1200, then there are a whole bunch of systems out there. I loved my old IBM of 6 years ago, but don't think they are built as well any more. Dells are nice in that you get just what you want, but usually at a slight price premium over standard systems. HP is like a Chevy. I've had Toshibas and they are heavy but very reliable. I am a special needs child (I run Linux as well as Windoze) but I have tried to keep that out of my advice. If you wish to consider converting, everyone I know who has a modern Mac simply loves it. Not as stable as Linux (which I usually reboot 2-3 times a year for upgrades) but significantly more so than Windoze. There is a price premium, but not that bad. Many of my old time computer friends use Macs now, so it's a much stronger system with OSX. I hope I didn't offend anyone with my attempt at making this humorous. I also hope that helps a bit. jerry

Maybe more than 90 MBH

@ February 1, 2005 10:00 AM in Furnace shutdown from CO

In the biggest burner contest the last time I wandered through a high end appliance store, I saw an 18K burner. You also forgot to add the 30 MBH oven. The only thing saving people is that most of these are for show, and the people of the house mostly know how to call for reservations. :) What I'm really envious of is the burners you see under the woks in chinese restaurants. They have quite a roar and look to have a 6" solic column of flame. Anyone ever work on one of these? We are already at the point where the stoves have more burner capacity than the boilers in some houses. go figure. jerry

Imagine a constest of these things

@ February 1, 2005 9:36 AM in Calling Mark Eatherton!

They do it every year in Delaware. Rules are that the pumpkin can't be frozen, has to come out of the barrel in one piece, three shot and the best one counts. No records in the big cannons this year, winner was just over 4000 feet. pumpkin chunkin My favorite story was it started in a farmers field. About a half mile away was a church and in the spitit of the event they put a target on the side of the roof. Then one year a pumpkin cleared the church by hundrds of feet, and they had to find a new velue.

Imagine a constest of these things

@ February 1, 2005 9:35 AM in Calling Mark Eatherton!

They do it every year in Delaware. Rules are that the pumpkin can't be frozen, has to come out of the barrel in one piece, three shot and the best one counts. pumpkin chuckin My favorite story was it started in a farmers field. About a half mile away was a church and in the spitit of the event they put a target on the side of the roof. Then one year a pumpkin cleared the church by hundrds of feet, and they had to find a new velue.

If you want it from ebay

@ February 1, 2005 2:31 AM in Pipecat

Jimmie, I'll ship it. :) jerry

be careful

@ February 1, 2005 2:28 AM in Electric or Hydronic

Nick, The long term economics are that electicity is less cost effective than fossil fuels for heating. There have been skews like this before, and people built heating systems thinking it would last forever. Boy did they get burned. Given it's almost impossible to retrofit from electric to anything else, I'd be really careful. I love the idea of two boilers, and if you can't swing that, at least have something that you can swap out should the price structures change. jerry

insulation is a science in itself

@ February 1, 2005 2:13 AM in Are there diferent heat calcs for differnt insulation?

As Constantin pointed out, there are several things that make different insulations work different in practice. One is the resistance to temperature flow through the medium. One is the ability of the medium to fill all the voids in the space to be insulated. Another is the amount of thermal bridging from things like studs. Another is the amount of moisture movement through the insulation medium. Add to this things like fire rating and cost, and there is no perfect insulation. The pink stuff is the worst, and everyone but the fiberglass people say this. It is very easy to leave voids (my rule of thumbb is a 5% void is a 50% loss in R value.) The air mothion through the medium is so high that it can produce internal convection currents that limit the overall insulation value. The glass won't burn but the binders burn very nicely. The panel stuff like polyiso is great as long as you foam it into place. Get a closed cell polyurethane foam and foam every edge and penertation to at least 3 inches. Same thing for XPS. Some people here swear by Icynene, but it's not my favorite foam. I can get much better closed cell foams at just about the same $/sqft/R, at least out this way. My ideal foam also has a low enough perm rating to qualify as a continuous vapour barrier, which is nice for a mixed heating/cooling climate. The trouble is that I know of no foam that meets the specs ans has a 1A fire rating. This means sheet rock or a fire resistant barrier over the whole thing. This almost doubled the insulating cost of one area. The lowest energy houses are being built with either SIPs or spray foam into I-beam wood studs. I live in shaky country (CA), and SIPs should be geat but are very uncommon. I'm not a general and two people have asked me to general for them on SIP houses they wanted to build. They must be really desperate, given I don't have a GC license! The load calculators have to derate the insulation for the assumed level of installation carelessness. If you get the insulation right, you should be able to reduce things. But guessing how much is really hard. First you have to decided how good your work will be, and second you have to guess what fudge factor the heal loss porgram included. Then you also need to look at the other losses like windows as well. I reduced the load on the A/C side by about 25% for my house, and am still fairly sure I'm oversized. I just couldn't bring myself to cut it by 40%, which is what I guess it will be. I'll know in a year. jerry

character assisnation is not necessary

@ January 29, 2005 3:28 PM in Has a deadbeat client taken you to the cleaners?

John, Yeah, right. It will be a frosty day in Dante's inferno before I show up there. I pay everything by the 10th or on a credit card. Try to pay my contractors within 5 days, they don't need to be my bank. In return, they take care of me. Once I tried rolling over a charge on my credit card. Didn't like it and haven't done it for 20 years. Thanks for playing. jerry

there is a cost to being \"right\"

@ January 29, 2005 11:28 AM in Has a deadbeat client taken you to the cleaners?

John, I stick by what I said. Will this site really be effective? How many people do you expect to post per year? What is the likelyhood that that person will come to someone else on the site within 5-10 years? Dave Yates has a great story about a part he ordered and never got paid for. He keeps it on the shelf to remind him not to make that mistake again. That's much more useful than listing the person as a deadbeat for not paying for the item. The question always comes down to how each of us act and where we put our energy. IMO, Chitlist seems like the wrong place to put your energy. I did some computer security consulting, and some of my perspective comes from that. First, the only way never to get your computer broken into is to make it unusable. Second, you have to do a clear analysis of what the real risks are. I've never had a customer that wasn't shocked when I did this. Never had a customer get more than 1 of my top three corporate risks. They were worried about tens of thousands of dollars, and I was seeing risks in the hundreds of millions! To me this is the same. Are you better off worrying about losing say a thousand dollars a year of non-payments or 10 or 20 grand on incorrectly charging for your work? How do you manage your investment in inventory assets against the need for the right part, right now? jerry

Let's not ride too high in the saddle

@ January 29, 2005 2:21 AM in Has a deadbeat client taken you to the cleaners?

Remember, there are probably more dollars lost and damage done by unscrupulous contractors to homeowners than homeowners taking contractors. So every time you get all cranked up about the $1000 you may lose in comparison to the $50 shoplifter, remember there are people who get hit for tens or hundreds of thousands of dollars. They spread a distrust that taints everyone in the trades. You have to deal with this every time you deal with a customer, though it may never be spoken. As with everything, I believe you need to find a balance. You need to accept some level of being burned, it happens to us all. I sure don't like it when it happens to me and I try to get smarter each time, but I don't let it color my view of my customers or my business relationships. If at the end of the year I had a good year, it's time to let the annoyances pass even when there is some pain. The Jews have a week of atonement at the end of their year, where you focus on how you have not been your best and seek to make it right. I think that is the right spirit for life. jerry

looks like stratos the pumps can go low enough

@ January 29, 2005 1:52 AM in Anybody have info on these Wilo pumps?

I looked at the pump curves, and the smaller units can run as low as 2m (6.5ft) head and from the curves show it running down to dead head. You just need to take out a second mortage to do it in a pump per zone design. jerry

can't wait

@ January 28, 2005 9:15 PM in Anybody have info on these Wilo pumps?

I talked with the Wilo folks many months ago. They were interested but had no schedule at that time. This is really exciting. They have a pump called the stratos that is the nicest pump I have ever seen. Uses an ECM motor on the pump, so it's the most efficienct unit out there. It comes with delta P and T sensors and can do all sorts of things. They also have pumps similar to the grundfos alpha with delta P sensors built in. If they bring these in at around the sam eprice point as the grundfos alpha in the UK, it will be a really exciting change. waiting and hoping, jerry

and more

@ January 27, 2005 12:05 PM in Radiant Ceiling

Scott, Not just insulate to drive the heat down, but also look for thermal bridges. The ceiling joists can also suck a bunch of heat out, especially for those looking to run the ceiling hot. With the suspended ceilings, that decoupling comes for free, so you just need the insulation to direct the heat. This is just the ratio of the insulation values. So an R1 sheetrock ceiling and R19 insulation on top would push well over 90% of the heat into the room. Remember to watch those voids! I'm solving this in a couple places by making sure the radiant surface in my ceiling areas is completely decoupled from the building insulation. jerry

more about the piping

@ January 27, 2005 11:50 AM in Hydro-Air

Dave, How are the flows to the two hydro-air zones controlled? Proportional or on/off, circulator or valve? What is exactly the lift distance from the expansion tank to the attic air handler? Here's my no information WAG. The upstairs Air Handler (AH) doesn't get flow when the downstairs unit is running. Without reset, the cycle times of the AHs will be proportional to the demand. As the demand increases, the downstairs zone continues to increase it's cycle time until the upstairs no longer has enough time to heat adequately. How I would test it would be to manually turn the upstairs AH on, set both thermostats to call for heat and watch the temp drop across the upper AH. Should tell you all you need, and you don't have to wait for cold weather. If this is right, then you need to figure out why. I would start with the system pressure. Here's why. If you are pumping away, the pump adds pressure to the distribution side. When the lower AH it not calling, the full pressure add of the pump goes to the attic unit. When the other AH calls, much of the dynamic pressure boost goes to the lower unit and thus no flow upstairs. The next thing for me would be to add a balancing valve to the lower AH, to make sure the flow to it isn't too much larger than the attic unit. It either of these don't solve it, then I would get a bigger pump. If my conjecture is correct, increasing the supply temps would make the problem go away, but not solve it. It's also why I wouldn't start with a bigger pump. It could again mask the problem without solving it. Let us know how it turns out. jerry

Calling ME on wall radiant

@ January 23, 2005 1:34 PM in Radiant Walls

ME, I know you did some of these for HfH. How have they turned out? jerry

I have a hockey son too

@ January 23, 2005 1:32 PM in Massive...

Mine's been doing it for a year, and just loves it. Sounds like you are doing travel hockey. That's too much for us. jerry

I'll bet some did go backwards through the pump

@ January 21, 2005 11:59 AM in A story from a boler inspector

Jay, It's a question of how much you can force. Using the oft quoted 1700 to 1 expansion for steam, a cup of water wants to produce over 10 cubic feet of steam. If this happens in 1/10th of a second for a flash, the pressure will increase to many hundreds of atmospheres in that time. The water in the pump will flow backwards, but you have an entire water system that the water would have to push through, pump, pipes, valves, well pump or city meter... There's no way that water can get out of the way fast enough to keep the pressure below burst point. jerry


@ January 21, 2005 1:17 AM in little yellow flashes in flame (Munchkin)

My initial thought is that you are sucking dirt/dust into the system, and the yellow flashes are that burning up. You made a comment elsewhere about black stuff in the combustion area, which would be consistent with this as well. Where is the air intake for the unit? What are the conditions around the air intake? jerry
« 1 2 3 4 5 6 7 8 ... 19 »