Moving forward on zoning heating system

[Rmelo99]

Ok, so I've made the decision that i'm going to zone my 3 level 1900 colonial. Quick backround, we aren't living there now and it is in major remodel/fix stages. Since I've already removed the master bedroom ceiling I've decided to remove the ceilings on the entire 2nd level.

This will allow me to access all radiator piping for the third level. So since I am in CT and we are heading into winter I need to keep the house heated for other work being performed.

Game plan is to do this in phases. Once all the rest of the ceilings are removed from the second. I plan on draining the heating system and disconnecting all the 3rd floor radiators. (4 cast iron old style). I will then either cap or connect the old 2 pipes to each other(copper) and refill system so I can heat levels 1 and 2. I can then move forward with the plan to run pex lines(yes I said pex) from the third radiators down to the basement where I will connect them to a manifold for new zone distribution. I plan on repeating this process for the 2nd and 1st floors when done. I do need to get the heat back on to the house between each phase.

Here are my unknowns that hopefully you guys can help with.

I need to decide brand or manifold system to go with. I need something that is pex compatible, not boiler specific. I was looking at the WATTS systems.

I still need to choose a pex manf to go with.

If this isn't the forum for help with my project, I would greatly appreciate a push in the right direction for help.

Thanks
Rem

 

[Jadnashua]

If you go with pex, you'll have to switch to a lower temperature system than you probably have now. Check the specs, but most boilers run between 180-205 degrees, and from what I remember, pex doesn't like it that warm. The amount of heat you can get out of things is determined by the incoming temp, the volume, the radiating surface, and the conductivity of the radiator.

TO keep the pex intact, you'd probably have to lower the temp, and the existing radiators are probably sized for higher temp, so won't cut it when max heat is called for. You'd have to put in a tempering valve to moderate the temp of the water to the radiators, which means they won't get as hot, which means less heat available in the room. Pex is better suited to in-floor radiant heat where the supply temp is often not over 100-120 degrees.

If you are planning on doing radiant floor heat, then pex is the way to go.

 

[Sponsor]

 

[Rmelo99]

From the specs I've looked at pex seems to have these ratings
73degrees at 160psi,180degrees at 100psi, 200degrees at 80psi.

From what i recall my boiler runs at like 15 or so PSI and I think is at either 160 or 180 degrees.

It looks as PEX can take higher temps at lower PSI's. I will check with a couple of the manufacturers to see what their response is.

A friend just had his house rezoned by a plumber and they ran pex to all his old style cast radiators. Not to say that makes it a correct install, but I would think a plumber would know better.

Am I the first to do this? I can't be.

 

[Rmelo99]

ok, since every boiler/plumbing/control company seems to have their own brand of pex tubing I went searching on the web to see what i can find on my own.

I did find on Weil-Mclain's website, under their "SNUG baseboard" radiators that

http://www.weil-mclain.com/radiant/snug.htm

"AlumiPex® Tubing can be used for piping from the boiler to baseboard units. This provides an easy-to-install, seamless installation: Solder radiant sweat fitting to the baseboard elements... allow solder joints to cool before attaching fittings... route tubing from boiler to element... refer to AlumiPex® fitting instructions for details. "

Now, their snug cast iron baseboards are just about identical to what I have in 85% of my house. I know burnham also makes a similar cast iron baseboard.

I did find a tech spec sheet for their "alumipex"
http://www.weil-mclain.com/FTP/Alumipex_Manuals/AlumiPex_Tube_Tech_Info.pdf

It lists that Long term temp limit at 203degees, and short term temp limit at 230degrees. Since most pex ratings I find are so close in spec I have to imagine they all follow some standard spec, but I do not want to use zurn/wisbro or another big player if they won't state the same as this weil-mlain product about using it for these cast baseboards

So is the temperature issue even an issue for me? I believe my system to run between 160-180 degrees. I can certainly run the calcs to see if I can run at the lower temp and still meet my heating demand.

Anybody...please help!

 

[Jadnashua]

Most of the people here aren't spe******ts in HVAC, so that is probably why you aren't getting any suggestions.

 

[Geniescience]

the right supplier, the right advice, the right fit

remi

is there a pex supplier who you like most? Buy from him as long as you are getting good service and advice. The pex manufacturers all have good products. Your big concerns are planning the big picture, and getting the right fittings in the right places. Am I right about this?

David

 

[Rmelo99]

Correct, I am in the planning design phases now. I have ordered my initial product online and they distribute from NY, I'm in CT so delivery should be quick. Also my local plumbing supply carries the same wirsbo if I am in a pinch for a fitting.