pex and cast iron bb and rads

kal_2

from the same atmosphere – so out the chimney and in the side is no good - - i just double checked the on-line manual at http://www.ecrinternational.com/secure/upload/document/389.pdf - page 20 sec A dot 1 and it concurs - sorry

a Lochinvar knight 105 with 3" PVC, will get you to 100 feet (minus 5ft per elbow) - and the small cpvc starter comes with the boiler – cant say anything good or bad about the Dunkirk as I have zero experience with it

you can always do a home grown coaxial end, ie: you run your two tubes wherever and when you need to go through the wall, you combine them coaxially, for termination, – long coaxes are not allowed – but long tubes with a real short coax termination run through the wall is ok

dont forget that the condensation will form icicles or ice sheets below it

nash

pex and cast iron

having new boiler installed in basement. I also would like to set basment up to become a tv room in future. Would love to get rid of the large pipes currently serving my hot water baseboards and radiators. installer said he could remove majority of pipes in basement and replace them with 1/2 pex. Do you think 1/2 pex will be large enough to supple the house. What size and type of pex would you recommend. Will I run into any problems with pex and cast iron ? Thanks in advance for your help.

Dave_4

moses of ENY Mechanical does this...

in 1/2" pex - 3/4 only for larger than 14 section sunrads, all home run's of course, and comes down the the wall on either side in the rear and attaches in a crossover fashion under the radiator without elbows, it's real nice - hope he's sees this post and puts up some pictures - you can use a brass manifold like Zurn or roll your own like he does

Moses

C/I Radiators & Pex Tubing

We did a 6 story building, 6 apartments, each apartment has a Larrs Mascott wall hung boiler, and 12 cast iron Sunrad radiators piped into, with 1/2" pex-tubing, 1 1/2" manifold. Each radiators is piped as a home-run to and from the manifold. The size of the radiators are from 6 section up to 16 sections.

We ars currently installing in a 7 story building, 14 apartments. In the second project we are installing Larrs Endurance EBP175. See attach pfotos.

I hope that will help you in your project

Moses

nash

pex and cast iron

thanks for the info. I guess the 1/2 pex is not going to be a problemas long as they are all home run.
any otther tips I need to be aware of. installer want to do a dunkirk q90-100 with indirect tank. he will run exhaust up chimney with pvc and intake from side of haouse with pvc as well.

thanks in advance

nash

You've given me things to think about. I really rather vent up my chimney, approx. 30ft. it has the clay pipe approx 6x9. if need be i believe I could fit 2 pipes up chimney. what types of worries do I need to consider in regards to ice. How should I terminate pipes at top of chimney. Does anyone have pictures of this.

thakns in advance

Uni R_2

Chimney Termination

The exhaust PVC piping on my Prestige was terminated 22' up though an empty chimney. Despite my contractor's strong reservations about using the SS screening for fear of ice buildup (I had bigger reservations about critters falling in or dropping larger objects in the tube) there was no ice observed all winter. The exhaust termination was high enough that the exhaust plume was never near the roof surface for ice to form.

I'd have rather run the intake through the chase as well (less chance of debris being ingested), but there wasn't enough room in a 6x6" clay-tile chase. As it was, the single 3" barely made the turn. The intake was run up the back side of the chimney with it's intake around half the height of the chimney after getting TT's blessing.

kal_2

if you can get two 3\" pipes through...

then, once through, refer to page 22,fig 9 of your install manual, the intake does a complete 180 with two elbows (be sure to put a bird screen in it, and make it higher than the highest snow ever), discharge tube goes straight up, and again with a screen – I use a straight pvc coupling on top which gives me a shoulder to rest a screen on,

once again, the Lochinvar boiler ships with two elbows with screens in them , and I move one of them to the straight coupling

you can read the knight manual at http://www.lochinvar.com/pdf/KB-i&o.pdf - you will find it more useful than the Dunkirk manual and might change your mind on the brand,
they break out the service manual and such – so do browse the site – don’t mind any point efficiency differences, the saving of a Mod-Con boiler is primarily in the load matching, I use tons of then in high temp applications only, with no chance for condensing, and the customer saves fortune by virtue of the fact that the boiler adjusts perfectly to the load –that’s where the real savings is!!! A point more or less is not big deal, a laars endurance is a non condensing high temp copper boiler that only modulates and only has an efficiency rating of 85+% yet it blows away cast iron boilers in it’s class by it’s modulation – if you take a therm of gas and fully condense it after combustion, you will get 1.21 gal of water and only 9000 extra btu, so clearly, that’s not where the primary saving is

if you cant get two 3” through the chimney – then you need to run them both to the side of the house or up to the roof

note: pvc pipe really expands and contracts a lot, so leave room, and wrap the pipe clamps with Teflon tape or you will hear crazy popping sounds – that will wake you at night – and if you go thorough the roof, then you need secure it there and douse it with silicone to leak proof it, and make sure it can expand below

kal_2

i do lots of non standard things...

But I watch over it personally and cant recommend it on the wall, eg I like to actually step up the discharge pipe near the boiler to get a pressure drop and more condensate out of the mix and then put a reducer outside to give it a jet effect for and almost invisible exhaust - I cant recommend it here, cause you have to work with combustion analyzers and pressure gauges and try it all modulation points, air pressures, temps to make sure you are not breaking the combustion paradigms, you could be sending unburned gas or carbon monoxide into an alleyway without even knowing it – so unless you know stociometry cold and have the tools and time at hand, I wouldn’t mess the factory recommended and ASME certified installation methods, just because it seems to work doesn’t mean it’s safe or efficient – you could easily move 10points in efficiency without seeing it in the flame - it’s all boils down (pun intended) to cost – a modern day car comes with tons of combustion computing – to handle the huge variations – it would add at least 2000 to the retail cost of a boiler, imagine boilers with a, mass airflow, o2, and dual pressure, and multi temp, and audio combustion sensors, with overpowered air pumps to handle everything we throw at it – where you put it all and who would pay for it - foh-ged-abow-eet – to be sure though, there will be more and more of that stuff as Americans demand European performance from their boilers – I agree with siggi, with the modcons already in the mid 90% on eff, the next big step first, will be lots more variable speed and efficient pumping technologies and piping

hot_rod

There are some mod cons that vent with 2\"

I doubt two 3" will fit in a 6" clay liner?

The Contender up to 120K will go 85 feet with 2". I have a 130K Phoenix in the shop that vents with 2" also.

hot rod

ALH_4

2\"

The Vitodens 100 will vent with 2" also.

Uni R_2

Please don't misunderstand me...

This was run by the mfr prior to the install, is still a much better solution than just taking inside air (which is an option for this and several other boilers) and was fully within specs when tested with a combustion analyzer after commissioning. I'm not advocating any home heating science experiments here - but the only way I could exhaust was up through the chimney.

My point was simply that the condensate plume freezing near the exhaust was never an issue using the chimney as a chase.

Kal Row

so does his dunkirk, but only for 15ft...

plus 4 elbows according to pg21 of the manual
http://www.ecrinternational.com/secure/upload/document/389.pdf

you can add 1.5ft for every elbow you dont use

Kal Row

two things...

a system that allows inside air to be used is not as accurate combustion wise so it's more tolerant, as they depend mainly on the pressure switch to tell them that all hell broke loose


as for plume, it varies greatly with the moisture content in the air, the amount of condensation going on, temp, etc, the good thing in this case is, with a cast iron load, there will be less than usual condensing, but he still needs to deal with the snow line, if he lives in an area that gets those 2ft wet blizzards, and doesn’t want to climb on the roof to clear his intake, then he need to set it up that way, if he runs the exhaust straight up with a coupling and a screen there should be no problem, but we had someone here on the wall a long time ago post a pic of a down pointing exhaust elbow with the ice going all the way down to the roof

I also like to look at the prevailing winds and put the stacks in parallel wind wise, so that they don’t get upstream or downstream of each other, whether the wind is blowing out of the southwest (fair weather) or northeast (poor weather) i really need to get a life

nash

Thanks for all the good info. I am still considering which boiler to go with, that will allow me to vent up my chimney and still be efficent.