Need some direction – looking to improve existing radiant setup

zavnet

I’m a homeowner who has been following many of the conversations and advises on this site. I truly appreciate the effort, knowledge and dedication many of you consistently provide.

Goal: Decrease propane consumption/heating costs…

Background:
Last winter burned appx 600 gallons each month (from Nov thru Mar). It been the highest propane usage to date.

The house was built in 2007. An internet based company (no longer in business) did the design, tube layout plans and provided all the parts for the radiant setup including the Polaris 199 BTU water heater (closed system) for the radiant and the DHW.

The tubes are Mr. PEX, and so were the original manifolds (w/o flow adjustment) – which I changed last year to Caleffi including complete re-piping, new HE and pumps (see below and attached pictures). Also added uponor joist trak heat transfer plates under the first floor.



In all past years (2007 thru 2013) on the "coldest day" the radiant heat struggled to keep up. Back in 2008 I added an electric heat plate to my HVAC units as a back-up – so that was the saving grace (at a price of course).

Since making manifolds upgrades etc., last summer -- I didn’t have to use the electric plates for the first time during the last winter (at last…)

After following many heat loss conversations on this site I did crunched the numbers using Slant/Fin and got ~ 167 BTU/HR – does that seem high/reasonable given the SF?

The house is well insulated -- entire envelop sprayed with open cell (beyond code requirements). My electric bill for cooling (Two-stage HVAC units 5 & 3.5 tons ea @ 21 SEER) is 13 cents on a dollar compared to the heating bill…

Additional info:
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• 4.5 Bathrooms
• (13) Thermostats (HAI Omnistat) – I know many of you think this is nuts – trust me this is not the culprit here. I don’t do any wild setbacks during heating season… For all occupied living areas the temp settings range from 68 to 70, and only gets lowered if we’re not home for an extended period…

Garage is not being currently heated. I have the two loops disconnected. Ultimately would like to keep it at 50 degrees so I can work in the workshop during the winter...
Basement is unfinished, the only insulation is reflective bubble foil under the tubes. I keep it at 65 degrees during the winter.

Known Issues:
• Most of the loops are 400+ in length – so no easy way out of this one… this was by design. I personally didn’t know better at the time…
• The tubes under 2nd floor don’t have heat transfer plates (was told not to bother by the company that designed the system… they are stapled + reflective foil). This is also where I have notice the smallest delta T – the heat is effectively not getting off/transferring well.
• I’m on my 3rd Polaris (the manufacture has been replacing them), typical run starting with the first one was 3-years or less. The first two developed small crack in the tank, leaked water and ignitor kept breaking. I also can’t seem to get rid of the smell when the unit is running – which seems like some level of exhaust issue. Checked for leaks multiple times, the gas leak detector is installed (never goes off…). My propane company looked at the this issue as well as the plumber -- neither was able solve it. The exhaust/air intake pipes were ran according to the mfg specs. I recall shortly after getting units installed the smell situation was virtually non existent. After a year or so the smell becomes noticeable.
• During the heating season Polaris cycling is very high, especially if multiple floors are calling. Through home automation tools at my disposal (around early March last winter) I created a program that gets it to 140 degrees, lets it go down to 120 and then starts it again – not sure though if that made a difference in the end.

Decision Points:
After spending many hours on this site I was convinced my Polaris was oversized causing short cycling. Looking at the heat loss calculation 167BTU/HR and Polaris at 199BTUs maybe not, at least on the surface?

I have no love lost with the Polaris unit (to put it mildly) and was thinking of switching to a mod/con as a preemptive action with the upcoming winter. Have been considering TT PT250 with Smart 60 or 80 for DHW or Lochinvar WHN199.

Was also planning to put mixing valves in front of each manifold to better control water temp for hardwood floor areas vs. concrete slab.

Bottom line I need to make further adjustments to gain fuel efficiencies and need some direction. Thanks in advanced.

zavnet

I'm in Putnam county NY. I did the heat loss calculation just recently using Slant/Fin. Back in 2007 when I assume the company that originally sold me the equipment did the heat loss calculations off the house plans I sent them. They never shared the actual math...

The basement is 50% below grade -- 10in concrete walls. No garage is not currently heated - the loops are disconnected. For heat loss calculation I used 50 degrees for the garage.

Rich_49

Was this no longer to exist radiant company based in Vermont or Montana ? Will have a better idea of exactly what you're dealing with .

zavnet

Not sure where they were based out of. The company name was Hannel-RadiantDirect

zavnet

Here is a pic of the original panel setup that came from them. It had a single 011 for the entire panel

Rich_49

I'd say your are due for a boiler and piping upgrade . it is a shame that the loop lengths are so damn long , not much of a chance to get some wire to water efficiency out of this .
You MUST insulate below the radiant tubing . R 13 at a minimum . Heat does not rise , hot air does .
Why is there also Ultra Fin below the heat emission plates with tubing in them ? Was this an attempt to make the system perform ?
Is there any boiler water additives to combat poor well water quality into the equipment ?

I suggest locating someone who is capable of redesigning this system to get FAR BETTER PERFORMANCE out of it .
You are using far more fuel than a customer whose system we worked on in November whose location is Plattsburgh , and he is running snow melt too .

zavnet

@Hatterasguy --- re-did heat loss calculations using Taco's FloPro Designer, overall got lower numbers across all areas (basement in particular)...
2nd floor - 57,200K
1st floor - 29,700K
Basement - 33,700K (old number was 52K)
Garage - 16,400K
Total: 137K

@Rich --- Yes, the UltraFins are there to get additional heat...
There is no boiler water additives -- the water is clean (with sulfur/softener and UV in place).

zavnet

I actually didn't see a place to plug that value in... In Slant/Fin it was 70 for the inside for most areas (0 outside). In FloPro the only editable section was "mean ground temp" which I didn't change...


So you don't think the Polaris is oversized?

4Johnpipe

Was just looking at this picture...Is the last loop tied into the supply and return manifold? Directly? I would cap that last loop if it is. The way it is set up with supply on bottom return on top it may be creating a flow issue...

zavnet

@4Johnpipe -- if you're referring to the below picture -- that setup no longer exists. The current piping pictures are at the beginning of the post (which will be further modified later this year...)