Heating Help

Here's an interesting read about it

@ January 10, 2012 12:55 PM in Flue temp and return water temp. condensing?

hopefully the pdf will show up this time.....my posts last night failed to upload the files.....

It is a function of temperature as well

@ January 10, 2012 12:48 PM in Flue temp and return water temp. condensing?

Flue gas (typical natural gas....not positive if propane is the same) begins condensing at sea level and atmospheric pressure at 133.8 degrees F. (although the dew point of natural gas elswhere I have read is actually 131.3 oF )  If your flue temp is lower than that.......condensing is taking place.........and of course.....the lower you go below that...........the MORE it is taking place......assuming that you have not yet fully condensed the total moisture in the gas.  I did a little research for some modulating scorched air furnaces we installed last year........and was told that the maximum condensate that could be produced by a 100,000 btuh burner was somewhere really close to 1.1 gallons an hour.

Pic didn't upload.....here I'll try

@ January 9, 2012 7:55 PM in 1950's Radiant Floor In School

again

1950's Radiant Floor In School

@ January 9, 2012 7:52 PM in 1950's Radiant Floor In School

Hi guys.......need a little help.  We take care of a 1950's Construction church/school that has radiant floors throughout every classroom and in the gym........it is MOSTLY working great, and the only leak we've experienced so far (it is copper pipe embedded in the slab......first wrapped in black sheathing) was last year........and thank God the priest agreed it was better to find and fix it than to start abandoning loops.  However.......we have really begun tearing into this thing now because there is a proactive principal at the school.  We just went through and rebuilt several Herman Nelson Steam Unit Ventilators.........and have attempted to get all the floor loops up and running (there  were 3 classrooms that didn't work......we were able to get 2 of the three up and running just by replacing the high vents on that circuit).  The last one is in a room where they carpeted over the little access plates that on the prints show a "balance and air" valve.  Once I gained access to the prints (mostly ruined laying in a basement that had flooded) I could tell where to start looking for the valve.......and just so we'd know what they looked like and how they operated, I went to one that was accessible.........in an area that they had LONG since abandoned the heat in the floor (just happened to be the principal's tiny little office) 
 What I saw for this valve was a brass hex fitting that was in line with the tubing, that had a screwdriver slot in the middle of it, and a little pinhole in the top of the brass near the ouitside of the top (looking down on it like I was the screwdriver).  Well........it did look familiar.......I have seen valves somewhat like these that were on return lines from heating zones in old houses that were built in the 60's, and all I know is that if you turned the screw perpendicular to the flow, it would shut the zone off.  The little office had it set exactly that way......and when I turned the screw parallel to the flow......Wallahh.......principal now has heat.  What I don't know yet is how the "air valve" part is supposed to work.  My guys have said that they can remember turning the screwdriver on one or two of these......and water coming out of the pinhole momentarily.......but 99% of them neither air nor water came out.  I can snap a picture of one later this week......but was wondering if these "balance and air" valves ring a bell with any of you??  I'm actually thinking that the air part is simply unthreading the brass hex part (packing??)  Any takers??  I drew a liitle picture of what I saw.......laying upside down in a closet.......with a flashlight in my teeth.....

Thanks in advance!!

Don

Can you draw a

@ January 5, 2012 6:27 PM in Hot water loop off steam boiler

wiring diagram showing what you did and the way it looked before you did it??

Yes

@ January 5, 2012 6:25 PM in Good control for electric radiant slab

I would.

Actually

@ January 5, 2012 5:40 PM in staple up insulation

We are primarily boiler retrofit contractors.........we don't actually lay a lot of tubing.......the last tubing we ran was with Ultra Fin .........and the main reason for that was that that particular system was mostly fin tube baseboard, and often needed 165-180 degree water temps.  Ultra Fin is about the only system that you can get away with that on.

that really depends

@ January 5, 2012 2:51 PM in staple up insulation

on which type of radiation you are using.  That type of insulation (6" of dead space) would work great for the UltraFin staple up (tubing hangs 1.5-2" from under the floor and has fin convectors that clamp around the tubing ever 30-50 inches depending on the heat loss).  For the standard staple up that is actually touching the floor.......I'd not want so much dead space.

Apples and Oranges

@ January 3, 2012 7:27 PM in Pump to or From modcon

PONPC is discussed only and mainly when deciding where to put an expansion tank.  These are normally in the building loop, and hydraulicly seperated from the boiler loop (which is the whole reason for primary/secondary right??) so the location of the pump on the boiler loop should be of no realtion to the PONPC.  That being said......always follow the manufacturer's instructions......but also find out WHY they want it that way or you'll just be one of those guys that does things for 30 years a certain way "because that's the way I've alsways done it and it works"  It is normally recommended to pump INTO your highest pressure drop (or friction loss), and it is recommended so that there is less (or no) chance of sucking a lower pressure elsewhere in the system.  What I love about this is that vendors overspecify pumps because they have no idea what kind of piping system is actually going to be installed (and the pumps are ALWAYS oversized eh??) and then the boiler manufacturers tell you to pump into the highest pressure drop because they know there is a high likelihood of the pump being oversized.  In a perfect world........you could do it either way.......especially on primary secondary boiler loops.  Be careful with indirects like Amtrol or Lochinvar where the pressure drops are pretty huge (usually a lot more than the common mod/con heat exhanger).  I use Triangle Tube indirects for two reasons.....1) they actually put a factory air bleeder on the boiler side top of the tank....and 2) they have 60% better recovery and a very low pressure drop.
Cheers!!
Don

That wouldn't fly around here

@ January 3, 2012 7:09 PM in Hartford loop

at all.......although on hydronic boilers they do allow us to use a flow switch (as long as it is manual reset) in place of the lwco........on a condensing boiler anyway.

Don

LWCO Took It's Place

@ January 3, 2012 6:52 PM in Hartford loop

Jim,
     I totally agree with you HOWEVER when the hartford loop was designed and implemented, it was to protect the boiler from a low water situation (on a rolling river) and there were no "low water cutoff" mechanical safeties at the time.  In our jurisdiction (and in every one I've ever heard of) there are TWO LWCO's required.......one being manual reset.  These safeties effectively take the place of the hartford loop.
Cheers!!
Don

If the Electric Heat is 208/240V

@ December 30, 2011 2:27 PM in Good control for electric radiant slab

I highly recommend this thermostat.  TL8230A1003 Honeywell LineVolt PRO Programmable Thermostat.  They are inexpensive (45-65 bucks) and I recently put two in on my electric radiant ceiling heat.  tehy work great and provide a very consistent zone temperature.  If it is 115V or low voltage this stat won't work and I have no experience to draw from for 115V or low voltage radiant.  Maybe look at www.warmfloor.com and see what they use.

Try This Out

@ March 29, 2011 3:27 PM in 1-wire pressure senors???

http://workaci.com/content/agp
Then click on "distributors" at the top and see where you can get it.  The LIST price shows as $285.00 but I buy them from alpscontrols for under 80 bucks.  Like I said, you are going to need to get a 4-20ma output transmitter and wire it in parallel with a 250 ohm resistor (1% or less tolerance) to change the signal to a 1-5vdc for your controller.

Nope.....not gonna happen.

@ March 28, 2011 5:44 PM in 1-wire pressure senors???

Fred......we do DDC controls all the time.  You need a 0-5VDC sensor, which is not very available, or you will need to buy a 4-20ma output pressure transmitter and install a high accuracy 250 ohm resitor in parallel with the transmitter (that will convert it from a 4-20ma to a ONE TO FIVE VOLT DC SIGNAL(1-5vdc signal).

One of the Lucky One's

@ March 14, 2011 3:24 PM in "BusYness" survey - Mad Dog

Hi Guys......I'm in Spokane, Washington, and my dept has grown from 3 techs to 5 techs in the last 6 months.  Commercial building that isn't public has dropped off the face of the earth.  We specialize in steam decentralization, and commercial boiler retrofits, and hae been very quiet in that area for almost 2 years now.  Today was the first time that I got a call from a homeowner who wanted to purchase a boiler himself and have us install it.  I decided to go ahead and do it on T&M for for.  In earlier times, there is no way I would have taken this on.....too much room for unsatisfaction......but I know the product he has, and I need to throw something at my lead guys that isn't maintenance just to shake up their week a little.  Maintenance agreements are basically 90% of our work right now......thank God we have them.  Last year during the last quarter, we landed a large public works project.......and thanks to it, we had the best year we ever had......but without that job....we would've been in the red for the second year in a row.  I was able to hire 5 people that were laid off from the same company to do the job, and lasst month hired a lead technician who was laid off from one of the big boys in town.......top notch guy......so sad that he was available.

relay or.........?

@ March 14, 2011 3:06 PM in New boiler and a few questions

Sounded like the vent damper slamming shut to me.  Although one of my guys installed a couple relays that were screwed to the inside of the Knight case once.......sounded like someone shooting a .22 long rifle vertime one of those relays made or broke.

Tim......

@ November 1, 2010 12:10 PM in HOW MUCH CONDENSATE???

Was this testing done to prove efficiency?  or was it for actually dtermining an amount of condensate?

well........how does it perform?

@ October 29, 2010 5:14 PM in opinion on piping

any banging?  hammering?  how long before steam hits the rads from a cold start?

Tim........could it ever be more than that?

@ October 29, 2010 5:12 PM in HOW MUCH CONDENSATE???

I found on HVAC-Talk that the "theoretical maximum" would be about 1.2 GPH.......and told the engineer that.......but have no "substance" to back up my claim with.
The mini pumps will do 1.3 GPH @13' lift.........I need to be damn sure that they will do the job.......as it is another one of MY hair-brained ideas.

Thanks

Don

Shark Bite

@ October 29, 2010 4:45 PM in is the flow rate of 3/4" pex enough

fittings can be bought at most ACE hardware stores........I think they'll do pretty much any material joining.......but you need to make sure before using them.

Bump

@ October 29, 2010 4:36 PM in Intrepid Install Quandry... Steamhead? Boilerpro?

Bump

HOW MUCH CONDENSATE???

@ October 29, 2010 4:31 PM in HOW MUCH CONDENSATE???

Hi......on pins and needles here.  I have to have my proposal done by the end of the day for replacing 44 furnaces in a school (I already got the job.....but the spec has been modified.)  I cannot get the vendor, the tech assistance guy, OR the factory to tell me the maximum amount of condensate that can be expected from a 120,000btuh modulating 95% furnace.  The engineer is waiting for me to answer him about this, because we are considering using mini pumps inside the furnaces due to a horrible lack of clearance on may that are in the ceiling, and he needs to do the review drawings ASAP.  Can anyone answer this question?  The make and model should not be important.......it should be the same for any of the same type of furnace.  Takers????