Joined on December 29, 2008
Last Post on December 9, 2013
@ August 20, 2013 5:54 AM in pipe ID and flow/BTUsWhy no O2 barrier? Is the wood boiler and all the components being used non ferrous? Here's the spec sheet for Uponor.
@ August 19, 2013 4:20 PM in Small 3/8" PEX manifoldsUponor TrueFlow Jrs?
@ August 18, 2013 10:16 AM in Radiant Heat not HeatingHouse wouldn't heat to 60 if you didn't.
The first thing to do is to re engineer the radiant system. Have a radiant heat loss and design calculated using the existing loops lengths etc. How would you be able to determine the needed water temp without it? Room again, is heating to 60 so you are transferring btu/hr out of the radiant.
Look for the 2" air gap between the tubing and insulation. No gap, no transfer of heat. Basically in the is application you are creating a convection oven in the bay. Need that gap.
You can stare at the boiler room all that you want, means nothing without knowing the heat loss and water temp required.
@ August 16, 2013 9:50 PM in Pex spacing for under floor radiant (joist bay)If its more about the lowest water temp. I shoot for what fits best to provide even comfortable heat across the floors. I don't care whether I need 120 or 100 as long as my floor surface temps are evenly distributed. Heat loss is a target, my tubing or application is my aiming device.
@ August 15, 2013 7:40 PM in Pex spacing for under floor radiant (joist bay)More btu/hr per sqft out of 1/2" Pex then you can with 3/8". The only advantage to using 1/2" Pex is a longer loop length of 50' more. If you've ever pulled both you'd know 3/8" is a heck of a lot easier to work with.
Nobody here can really say if it will work or not without calculating a radiant heat loss and design. I've fix hundreds of jobs by reverse engineering them and let me tell you. The fix some times cost more then the initial installation.
@ August 15, 2013 7:35 PM in Pex spacing for under floor radiant (joist bay)May I please see the radiant heat loss and design your prepared prior to the installation in writing unless you wish me to have my lawyer prepare a formal letter requesting it. Until I see and review the heat loss and design you must stop all work.
@ August 15, 2013 7:22 PM in Grunfos AlphaOnce said, water is dumb, lazy, why would it want go there no matter forward or backward?
Hmm. What's a typical old hydronic system? Didn't know there was one. Mono flow? Old gravity steam system converted? Your looking for an answer with little information brought to the table.
To answer your question about the Alpha. Sure it will, its a pump, plug it in, impeller moves and presto, so does the water. PS. A circulator pump will move water 200 years in the future too.
@ August 15, 2013 5:45 PM in Primary / Secondary BasicsYou won't see a mix in the secondary. The mix will happen where the primary return and secondary return intersect.
See if I can make this easy for you to see
10gpm 100 degree water leaves Pri Circ Pump
5 gpm of 100 degree water enters the secondary
5gpm of 100 degree water flows down the primary between the two tees
5gpm of 80 degree waters leave the secondary return
10gpm of X is now in the primary return
(5 x 100) + (5 x 80) = 10X
500 + 400 = 900/10 = 90 Degree Water is in the primary return at the point both the primary return and secondary return intersect.
Do you know the water temp and flow rate leaving the pri circ?
Do you know the flow rate entering the secondary?
Do you know the design delta-t in the secondary?
Answer these and I'll give you the temp the math is here for you if you want to do it yourself.
@ August 14, 2013 11:01 PM in pipe ID and flow/BTUsI'll just use 10gpm based off the specs on the indirect. I'm assuming its an SSU60 (Stainless Steel). The head has the indirect pressure drop in it.
1" Pex = 10gpm @ 35' of head
1-1/4" Pex = 10gpm @ 19' of head
1-1/2' Pex = 10gpm @ 13' of head
In the end your going to still need that boiler as back up.
@ August 14, 2013 10:36 PM in pipe ID and flow/BTUsI didn't see that extra 60' of 3/4" pex in the basement. 65 to the house then 30 to the Indirect is 95' and there has to be a return so that's another 95' for a total run of 190'.. I added in the 8' of head for the indirect pressure drop..
1" Pex 10gpm @ 30' of head
1-1/4" Pex 15gpm @ 25' of head
1-1/2" Pex 20gpm @ 21' of head
I don't think his existing pipe is leaching btu/hr, it's that his existing pipe size and pump are so small he can't move water..
@ August 14, 2013 10:16 PM in pipe ID and flow/BTUsHe can't move the required flow across it's HX. Pressure drop across that coil is 8'. Add the numbers I posted above to that and he needs one big pump.. His biggest problem is his pipe size choice. If he wants to stick with 1" he needs a tank much bigger then 60 gallons.
@ August 14, 2013 9:54 PM in pipe ID and flow/BTUsIts acting like a heat exchanger. What size is it? Here's the question of the day...Have you done a heat loss of the house? I haven't read in any of your posts as to what the heat loss is..I'm a betting man,, 3800 sqft of heating space let's see,,, I'd say around 70,000 or so..
@ August 14, 2013 9:34 PM in pipe ID and flow/BTUsYou want a buffer tank..A place to park the btu's being made by the wood boiler. Where are you located?
By the way, 1" Pex with 100 percent water at 180 degrees moving 10gpm, 150 feet, has a head loss of 17.2ft at a velocity of 5.5 ft per second.. Still want to use 1" pex?
1-1/4" Pex with 100 percent water at 180 degrees moving 15gpm, 150 feet has a head loss of 13' at the same 5.5ft per second velocity.
1-1/2" Pex with 100 percent water at 180 degrees moving 20gpm, 150 feet has a head loss of 10' at the same velocity as above..
@ August 14, 2013 6:50 PM in pipe ID and flow/BTUsgpm = btu/hr / (delta-t x 500) The 500 is constant unless you have a glycol mix. Once you calculate your flow rate you then need to find the pressure drop chart for that PEX and figure out head of foot. From there find a pump curve chart on Taco's web site and find your pump..
@ August 14, 2013 4:31 PM in Primary / Secondary BasicsYour mixed water temp is going to happen where the secondary return enters the primary return. In diagram 1 your mixed temp is going to happen after the secondary return which is going to drop the temp entering into the primary supply before the secondary supply.. Not a good thing..Your secondary is always going to consistently see cooler water. Might not be a bad thing for radiant cooling.. All depends I guess. What is the design water temp flowing out the primary circulator? What was the water temp design flowing to the secondary? GPM design for both would also be help. It's just simple math.
@ August 14, 2013 7:06 AM in Primary / Secondary BasicsYou have 8 leaving the primary circ. You pick up 4 at the secondary return so you have 12 flowing in between the tees, 4 leaves to the secondary supply tee leaving 8 flowing back down the primary return.
In diagram 2. You have 8 leaving the primary circ. 4 Enters the secondary supply so you have 4 left flowing in between your tees. 4 comes back at the secondary return and 8 flows back down the primary return.
Always remember. What enters a tee must leave a tee.
Either way you have the same 4gpm flow into the secondary. The question again is what is that water temp? You are move 4gpm of x piped either way. Diagram 1 is going to get you in trouble from a water temp standpoint not from a flow standpoint.
@ August 13, 2013 9:02 PM in Weil Mclain vs. Lennox boiler?Measure the radiators yourself and calculate the sqft of steam you need. It's not hard..
@ August 13, 2013 8:13 PM in Converting from oil to natural gas - Navien CH210 was recommendedI'm disappointed not to receive a comment on why the heat loss is important. Feel left out. Thought I made a valid point, it is reality..
@ August 13, 2013 7:53 PM in Primary / Secondary BasicsMust leave a tee. Yes you will have a mix water temp in pic one..
Say the Main loop is flowing 8gpm of 180 degree water. The secondary loop is taking 4gpm of X...For design purposes we designed for a 20 degree delta-t on the secondary for a 180 supply and a return of 160 degree water.
(8*180) + (4*160) = 12X in the primary loop
1140 + 640/12 = 148 Degree Water blending in the primary loop before the secondary could takes its needed under these design conditions.
So you wouldn't have 160 degree water returning in the secondary because you can only make 148 degree water to supply the secondary. In other words, you'd never get the supply water temp you needed through the heat exchanger. You'd get the flow you wanted but that's about it.
Don't confuse flow with btu/hr because your just moving it. What the HX can emmitt/transfer is based on the water temp/flow that btu/hr is flowing in.
@ August 13, 2013 6:18 PM in Weil Mclain vs. Lennox boiler?Is not sized by btu/hr but rather by square foot of radiation. The radiators needs to be measured for their edr out put..
@ August 13, 2013 4:57 PM in Weil Mclain vs. Lennox boiler?250,000 /3,600 = 69.4 btu/hr sqft..I suggest you spend money on new windows and insulation. Lennox is a Dunkirk Boiler re labeled and I wouldn't touch a Weil if you paid me. By the way at that btu/hr output per sqft your curtains will be blowing like a kite in March...
@ August 12, 2013 5:52 PM in Please Judge my layout...What pump did you choose for your primary/boiler pump? You do realize your not going to move all that boilers capable btu/hr through 1-1/4" pipe unless you size that pump correctly and a UPS26-99 isn't going to be the right pump. What is your system side flow rate requirement?