Crested Butte, Colorado house update

billyboy

My Sons new house in CB, radiant heating system is working well in its 1st Winter.
Zone 7, design temp -20*F, about 2,500ft2 inside house, mostly has hardwood floors over 3/4" OSB subfloors, tile in bathrooms, with attached 600ft2 garage. Huge, over the top, amount of glass.

Architect did ResCheck & came up with 113,000 Btu/hr at -20*F

I used a Burnham ESC6 sidewall vented cast iron boiler (cheap & reliable) as emitters are high temp (150* AWT) at -20*F
Boiler TT is controlled by a Tekmar 256 ODR (30*F DT) with its system sensor surface mounted on middle of the Rheem ST120 3 port (1-1/4") DHW / Buffer tank.

Heat from boiler goes through a 30 plate heat exchanger to heat the tank. Water from the tank bottom port is pumped through the heat exchanger and returned to the tank middle port, the system can also heat during this.

If the boiler is off, and the system calls for heat, heat can be pulled out of the tank (Buffer mode) from the tank top port (hottest) through the heat exchanger, and returned to the tank middle port. A 3-way motorized 8.3CV 1-1/4" valve switches between the tanks top & bottom water source ports, controlled by the boiler along with the boiler pump.

The garage slab is the only high mass zone, with its heated water mixed down from tank reset temperature with continuous circulation.

The 4 zones inside the house used over 9,000' of suspended 1/2" pex at 4" on center + 500' of 3/4" to/from manifolds.
I also put suspended pex in every interior wall at 8" on center up to 8' high. Walls run from 10' to 22' high.

I know almost all on here say this can't work, & should never be attempted, but it does work fine.
I read Bob Gagnon's posts on tight spaced suspended pex & I studied this quite a bit, including Wirsbo testing info.

rick in Alaska

Is this zone 7 part of another 2-3000 square feet? 113,000 btu will heat a lot of house, so I am assuming it is not just 2500 square feet?
What is the reason for using a plate heat exchanger? Is part of the system antifreeze?
With the amount of tubing you put in, you should be very comfortable.
Rick

Zman

It's not that you can't, but why would you? With the extra money you spent on all the tubing and labor, you could have done a properly designed system.
Any architect that designed a home with a heat loss of 45btu/ft should be ashamed of themselves, even in Crested Butte. They are either the worst architect ever or they don't know how to do a heat loss, I suspect it is the latter.
What kind of cycles does the boiler do on design day?
The buffer tank is a good idea with an oversized boiler.

Sorry for the rant, I am glad your system is performing well. It is just a really strange way to get there. I think you started with a completely inaccurate heat loss, then ran an insane amount of tubing. I am not at all surprised it works, I see ton's of old staple up plateless 3/8" tubing jobs that keep up just fine, also some that don't work at all.
My point is, the whole thing was a giant SWAG and things fortunately worked out....

billyboy

Heat transfer plates were out of the equation given every hardwood floor in the house has many many nails through the subfloors.

My Son vetoed wall panel radiators ($$$)

On design day boiler takes long on cycles, 1-2 hrs, then off for 15 minutes +-

Only problem thus far: 2 Taco 007 pumps have krapped out & the system pump (Grundfos Alpha) still pumps water fine but its user display quit working from a power outage spike.

Also the Tekmar 256 outdoor sensor reads 20* +- too high & had to compensated for in setting the reset curve.

The plumbers did all the fixture pipes and the recirculation (which they cut some corners somewhere) So I have to run the small recirc pump full speed 24/7

billyboy

Another issue is with the Ecobee3 thermostats that my Son wanted.

Some control just fine, but those that their IR sensor is aimed across a room at cold windows, have to be set 10 to 20* degrees below the desired room temperature.

He has added secondary external sensors, but the Ecobee's average the 2 sensors & still have to be set much lower than the desired room temperature.

bob_46

Went to school in Gunisson in 59 we always called it Crusty Patute .

billyboy

Rick:

2,500ft2 inside house. Garage is additional 600ft2 slab.

Yes, glycol 33% is in system / boiler side of the heat exchanger.

The heat exchanger allows for a large (115 gal.) fresh water DHW
Tank to also act as a buffer tank.

billyboy

Steam shower & large jetted tub work fine with the big DHW tank.

billyboy

Labor cost for pulling all the pex was $5,000 my time was free, donated to my Son, as I'm retired.
Pex cost about $6,000

If we didn't have all the nails to contend with and used heat transfer plates, how much more would the total cost be?

Include:
heat transfer plate cost,
Increased labor cost,
Decreased pex cost.

My guess is about double.

Mark Eatherton

billyboy said:

Labor cost for pulling all the pex was $5,000 my time was free, donated to my Son, as I'm retired.
Pex cost about $6,000

If we didn't have all the nails to contend with and used heat transfer plates, how much more would the total cost be?

Include:
heat transfer plate cost,
Increased labor cost,
Decreased pex cost.

My guess is about double.

You didn't (don't) value your labor?? Even if you are retired, your time is worth something...

I'd also venture a guess that when the PEX goes through a cold start, that the expansion makes noise. TIck, tick, tick, tick, tick....

In my book, noises associated with the heating system does not fit into the equation of comfort.

As others have said, sure you can do it, but why, when there are much better, much more efficient ways to do it?

You get what you pay for, or in some cases, you don't get what you don't pay for. I guess in your minds eye, you won.

BUT WHAT DID YOU PROVE?

You proved that you can deliver heat... Heat is but one component of comfort. Yes, radiant floors are one of the most comfortable methods of comfort delivery available, but the associated expansion/contraction noise would drive me out of the house.

Sorry to seem so harsh. I am not a fan of this type of system, and have responded to many complaints around the cost of operation and associated noises to their operation. I therefore cannot endorse this sort of system.

PS, I had it in my home at one time, and have since yanked it out and put in plates and a proper (modcon) heat source.

ME

Gordy

As for the nails from the flooring protruding excuse. A fastener in air adds zero holding power to the assembly. Use the appropriate length fastener. That drives me crazy.

Zman

Gordy said:

As for the nails from the flooring protruding excuse. A fastener in air adds zero holding power to the assembly. Use the appropriate length fastener. That drives me crazy.

I have seen a few ugly ones where the tubing got hit dozens of times.
I started confiscating all the incorrect nails from the flooring installers until the job was complete. All it takes is on laborer to trash the whole thing.

Alan (California Radiant) Forbes

I love Crested Butte! Beautiful town with wonderful mountain biking trails.

I've never, ever been chased by a horsefly for a longer period of time than in Crested Butte, and I was on a bike. Guess who won?

I don't know why more people don't use Ulta-Fin. You could have snapped the fins on your suspended tube and decreased the water temperature. You could also have installed a condensing boiler with an indirect water heater.

Why do all these people come to us after the house is built?

Mark Eatherton

I've never, ever been chased by a horsefly for a longer period of time than in Crested Butte, and I was on a bike. Guess who won?


The horsefly, of course!

ME

Solid_Fuel_Man

I honestly don't know why they even call them horseflies....should be humanflies! Maybe it's because they are as fast as a horse.

billyboy

No expansion noise at all.

All the pex is held away from the wood framing with plastic nail in clips & every pass through the wood framing has the split loom sleeve plastic around the pex.

System works great at design temp. (-20*F)
The boiler is on about 60% & off about 40% so it should keep up fine at -30*F