Heating Help

Wirsbo Hepex leak/delamination?

@ November 22, 2011 2:10 PM in Wirsbo Hepex leak/delamination?

This Hepex is  roughly 15 years old, poured slab on grade. It has had dowfrost at about 30% strength since new. The paint overspray is just latex. The fittings are compression style wirsbo, and have obviously been leaking awhile (it has taken me forever to figure out where the water has been going in this system...duh).  When you examine the hepex closely, it seems the outer lamination, at least on this one end, is separating?!

I would like to replace the compression fittings with propex. I will have to cut it back some anyway, so I may use propex splices, and add new hepex above, to get me some working length, since I don't want the manifolds right on the floor (they are now about a foot off the slab.

Does anyone see a problem with this approach? Has anyone seen this in wirsbo hepex before?

TT for boiler...

@ May 16, 2011 6:05 PM in Comments on Schematic?

Could you also use a flow switch?

glycol pig.

@ May 16, 2011 6:01 PM in glycol feeder and mold

...that's a tidy solution.

heat dumping for homeowners?

@ April 30, 2011 8:38 AM in No April Fools here...

An idea I had very recently for dumping excess solar heat was to dump it near below grade walls, preferably under foam insulation.  You could recover it, if you wanted to, but otherwise, it just lowers heat lost.  The caveats for other ground storage still apply, but the storage temps are very low, maximizing BTU's even on low output days.

My original thought was for solar snowmelt, where water temps can be very low and still usable.  Once those areas are satisfied, and during "off season", might as well use those free btu's.  After DHW preheat, and any other low temp scavenging, this seems like another efficient way to uselow temp  "leftovers".

plates

@ March 6, 2011 5:34 PM in Starting the planning for an underfloor system. Have questions.

If your worried about efficiency, use plates.  If your doing staple up with plates, use pex-al-pex, even though it is a serious pain to work with (kinks very easily).

Know your heat loss.  Shoot for outdoor reset and condensing boiler.

quiet pex

@ March 6, 2011 5:23 PM in Noisy Pex

Kungar, that is about when I started to really notice the noise, in the spring.  My final fix was to tear out the hepex and install pex-al-pex.  I don't have outdoor reset, but the system is silent, now.  Outdoor reset and mixing might help, I dunno, but I'm pretty much sold on PAP for plated staple-up.

John

you can drill it...

@ January 19, 2011 9:43 PM in Retrofit on slab on grade.

If you get a concrete bit, you can drill a hole int he slab to check what's under it.  I did mine to see, and found...nothing.  In Alaska.  Really?.  Anyway...  easy to patch with a bit of wet concrete, or even epoxy.

a couple more...

@ December 26, 2010 12:01 PM in DIY Heat Loss Calculator?

for rough numbers...
http://www.dimplex.com/customer_support/heat_loss_calculator
http://www.builditsolar.com/References/Calculators/HeatLoss/HeatLoss.htm
download-able excel sheet; http://www.warmmfloors.com/heat_loss_calculation.htm

another arangement?

@ December 25, 2010 9:39 PM in Dumb Q...High temp ret. to low temp emitters?

here they are staggered...?

Ok, dual buffers...?

@ December 25, 2010 9:38 PM in Dumb Q...High temp ret. to low temp emitters?

here they are stacked...

my first guess is not...

@ December 15, 2010 5:06 AM in O2 barrier PEX or not?

Unless it says somewhere DIN 4726, or EVOH...
ASTM F876/877 and CSA 137.5 are both potable water specs for pex.  I don't know what pp101 signifies.

conversely...

@ December 10, 2010 6:02 AM in Balance setting between Wirsbo and Forced air???

if the basement floor is cold, it doesn't matter that the air temp is above 70 deg. from the forced hot air, that radiant transfer makes the room cold...

my cold climate staple up...

@ December 10, 2010 5:57 AM in My radiant floor

My experience with my little pilot retrofit project is similar.  I've recently, in this cold spell, been turning DOWN the water temp...getting return temps below 100 deg. with thin plate staple up, ambient temps approaching 0 deg F (Anchorage, Alaska).  I'm starting to wonder if I still need to mix down the pex-in-slab zones...we'll see when I start up the first two rooms in a few weeks.

Only problem with lower water temps is that noisy pump running more.  It must be something with the plumbing, even though the suction is more than 12D, and the check is far enough downstream (maybe I should try closing down the Wirsbo manifold balance valves?).

Gonna try the Grundfos Alpha, with a Webstone check/flange for the low temp, running Wirsbo motorized zone valves, and micro-zoning each bedroom.  This is for thin-slab (2" concrete) over 2" foam over existing uninsulated below ground slab.

Not that it's been easy, learning the hard way.  So much dis-information out there.

John

P/S for each zone?!

@ November 14, 2010 12:36 PM in Dumb Q...High temp ret. to low temp emitters?

or for each required supply temp?  'Cause I did think about using the high temp returns, and a mixing valve, to set the lwoer temp supply, but I havent drawn that out to look at it yet, and again...the hydraulic separation is an issue.
Since the return temp of the high temp zones will just be supply temp minus the BTU's needed, and the return from the low temp the same, and the return TO THE BOILER will be the mass flow rate weighted average temp of the returns from each, which will be, effectively, the original supply temp, minus the BTU's delivered to the whole system, at whatever the flow rate is, and I'm not gonna do the math.  Is this the answer to why?
I still think a buffer tank with good baffles and stratification, and center taps, for both high temp returns and lower temp supply would make some thermodynamic sense...but I don't have a good argument for it.

John

oops

@ November 13, 2010 8:29 PM in Dumb Q...High temp ret. to low temp emitters?

I knew I should have waited to post this and thought about it a little more. I just realized my schematic is NOT hydraulically isolated. I suspected as much, but couldn't see it.

Dumb Q...High temp ret. to low temp emitters?

@ November 13, 2010 6:39 PM in Dumb Q...High temp ret. to low temp emitters?

IF your mod-con boiler efficiency is so dependent on return water temps being low, and IF you have a system with both higher temp emitters and lower temp, why not route the high temp return to the low temp supply (or pull your low temp supply from the high temp return)? Not as a way to avoid mixing down for lower temp supply (still prob. have to mix down), but for efficiency.   Assuming you can keep things sufficiently hydraulically separated, wouldn't this minimize return water temps?

This may have been proposed somewhere already, but I haven't seen it.  If so, please give me the brief on why its not worth it.

A possible  arrangement...at least it shows the idea.  Seems like tapping the buffer tank mid-way down would make the most sense.

John

uponor...

@ August 24, 2010 4:48 PM in Splice or one piece? (PEX)

kcopp, pretty sure that store does still sell hepex, though it's been awhile since I ordered.

Slam, wait for barrier pex...it's really hard and expensive to do it over, way too cheap and easy to NOT do it now.  I'm currently working on some retrofit...

good luck

what he said...

@ August 23, 2010 11:54 AM in Splice or one piece? (PEX)

Non o2 barrier pex never works out economically if you figure a bronze circ. pump, and if you need a heat exchanger for the boiler...forget it.

Your best bet for estimating pex length is run the heat loss and find out how many BTU's/sqft you need, BUT...running 1/2" pex in concrete for a shop, built to current standards, you will probably be ok to run every 12", 300' max each loop, so 1200' total, 4 loops.  You could go longer loops and maybe wider spacing with 5/8", or even 3/4", and in a shop that would be fine, but you will feel the difference as uneven heat across the floor surface.  My garage has 1/2" every foot, and you can feel the temp difference when barefoot, BUT, I have a concrete garage floor that you can walk barefoot on all day...

Insulate and vapor barrier under the slab...

John

Flate-plate DHW?

@ August 20, 2010 12:30 PM in Flate-plate DHW?

I can find virtually NO info on off the shelf, flat-plate, tankless or buffer tank, DHW in the US.  I think they do it in Europe.  Is it the economics of delivering the volume of hot water we use in North America (flat plates cost as much as the indirect tanks, not including controls...).

John

improper installation details, maybe...but what?

@ August 18, 2010 8:32 PM in radiant heat pex noise...snap, crackle, pop--can't sleep--help!

My installation details look just like all the others I've seen on the web and elsewhere...not to say it's right.  Pex runs through 1 1/4" holes in TJI's, held by the split plastic "donut" clamps at each TJI penetration, at one end of the runs.  The pex then runs full length of each joist bay, held up by either stamped or extruded plates.  I only used a couple of talons, in areas far removed from the worst of the noise.  I used plastic split loom anywhere pex ran through wood that I couldn't use the split "donut" clamps.  The original installation was all stamped plates.  I tried pulling those down and using extruded plates for a large portion of one room, with little difference.  The final configuration for the PAP was to use extruded plates at room perimeters, stamped for interior areas.

Just seems like, hepex growing 1" per 100' per 10 deg.F. change...if my water temp is a low 110 deg, and ambient is 70, for a 25' run it still MUST grow 1".  If that expansion is shared evenly at each end, there must be 1/2" of expansion.  Even if you put an expansion loop every 4" (one for each extruded plate), the pex must expand .166" over that 4' length, which is ten times more than the aluminum.  There is just no way I can see that the plate can hang on to the pex that must grow 1/10" per plate, existing installations not withstanding.

my guess...

@ August 18, 2010 6:21 PM in radiant heat pex noise...snap, crackle, pop--can't sleep--help!

My estimation, Rob, is that it was the diff. expansion rates of pex and aluminum.  Like I said, i could WATCH the pex jump out of the plates.  The much lower rate of expansion of pex-al-pex must also contribute, it just doesn't expand nearly as much.  The runs are 24', 1/2" pex.  I did have wirsbo hepex with plates, both stamped and extruded, now running Mr. Pex pex-al-pex, the water temps are similar (120-150 deg. F).

I only changed out 600' of tubing (two loops), and, like I said, glad I had a chance to get it right before i put the lid on.  Just this week we poured 2" concrete over 1/2" hepex over 2" xps over existing below-grade slab for the rooms below  (leaves us 7'8" headroom) - the project proceeds, finally.

pex-al-pex, so far, so good.

@ August 18, 2010 4:43 PM in radiant heat pex noise...snap, crackle, pop--can't sleep--help!

Outside temps are still pretty high, and water temps not fully ramped up, but just using pex-al-pex instead of hepex with aluminum plates has made a huge difference in start-up noise.  It can go from ambient to 130 deg. water without a discernible pop.  The pex-al-pex is more difficult to work with, as it LIKES to kink.  I had to watch almost every bend as we pulled loops...it takes more people.  It seems worth it in the end, though, and I'm glad I found a solution.  Seigenthaler nailed that one (using pex-al-pex for staple-up with plates).

John C.