Am I rolling the Dice with Kitec here?

G_Love

We own a 2007 build house and it is roughed in for hydronic heat in the garage (2 loops)and basement (4 loops). The problem is that the in floor loops are orange Kitec. Wierdly enough none of the water runs are though. The contractor is looking into alternate fittings but how big a risk am I running of a major leak down the road? I read and signed up for the class action suit just in case but should I press on here?

The plan is to replace the water heater with a Navien 240 ASME, one zone in the garage (24'x24'), two zones in the basement (1200 sq ft). Here's the kicker: This area has hard water, cold inlet temps and winter gets to below -40 occasionally and -35 for significant periods. I am planning on using glycol/water in the closed loops.

Am I making a huge mistake?

Zman

Heat loss

You should be able to manage the Kitec without much trouble. http://www.heatinghelp.com/forum-thread/135233/Kitec-Tubing-and-fittings



You may want to send Mark Eatherton a note for more info.



Why would you install a 240,000 BTU boiler?

Have you done a heat loss? You are oversized to your heat loss by at least 4x

Carl

G_Love

Underutilized?

I suspect that the contractor (who is generally well regarded here) is probably giving me some overcapacity, which is something that has come up in other forums when I was doing my research. If I understand the theory, it is easier to put in a larger unit and not have the customer complain if they run short of hot water. With a mod-con boiler is that going to be an issue?  I definitely don't want to short cycle the unit either.



The other side of the coin here is that the inlet water here in NE Alberta is COLD, especially in winter. The mean water temp from the lake (our water supply) is 4C. I only intend to heat the garage to 10C or so but even as insulated as it is that means pulling up the temp from -20 for the four coldest months. I'll run some heat loss calculations and see where I end up.

Thanks for the link on the Kitec, that's my larger concern at the moment.

G_Love

Heat Loss Calcs

I did my heat loss calcs and were as follows:

Living rm- 5900

Kitchen- 7582

Small BR- 2592

Spare BR- 3569

M BR - 4849

Garage - 51119

basement- 25 594

Total: 101,205 BTUs/hr assuming all rms 70F.  This will in fact be somewhat lower as I intend to run the garage at 50-60 F normally and my basement will be getting better insulation.

I agree that a 240k unit is way overkill but in contacting my contractor we agree that a mod con boiler is better than tankless due to my inlet temps. I'm leaning toward NTI, but I'm open to suggestions if anyone is willing to share!

kcopp

Hmmm...

Basement and garage numbers look suspect.  What is your hot water load? # of people and bathrooms? I would shy away from the Navien... a few have had good experiences more not so much.

I would do a separate indirect and a mod con w/ a good track record. Triangle tube Presige solo, Bosch Greenstar & Embassy/ Smith Onex are what I use. That being said something that the installer can get parts for quick if needed and knows very well.

G_Love

Garage/Basement

When I did the calculations for the garage I listed the insulation as poor due to the doublewide car door and air infiltration. The basement I listed as R5 although the exterior walls have 2x4 walls with pink insulation and 1/2' gyproc. The floors are bare concrete, two feet above grade, 8" ceilings. The R value is likely somewhat higher but it's still lossy.

I will be installing a boiler vice the Navien combi after talking with a few more plumbers and people that have had tankless heaters installed here. The rise required is too much for most tankless systems, especially in winter.



As far as the hot water load, 4 people, 3 bathrooms, although one isn't built yet. That'll be done when I finish the basement.

NRT_Rob

both

your garage and basement numbers are at least twice as high as reality would allow for.

G_Love

Recalc

OK, I went back and redid my garage and basement losses...

Garage, 37 888 btu/hr

This is based on degree days and specs for Edmonton AB which is the nearest major city to me,5708 degree days and -25F coldest day AFAIK. Cold Lake is actually 5920.

24'x24' slab on grade, 8' ceiling with 1/2" gyproc and 6" pink insulation ceilings and walls which are sheathed osb and sided with vinyl, unheated and vented attic space in rafters. Garage door is 80x192" metal clad and insulated. I assumed avg infiltration and have one double glazed sealed window 32x18". I have three exterior walls, the fourth is against the house.



Basement 23494 btu/hr

Same as above for degree days, 30'x40', three ext walls, 8' ceiling, 3' above grade. 6 windows, double glazed, sealed, roughly 30x32" each. Ext walls against concrete are 2x4, pink insulation, 1/2" gyproc. Concrete floor, bare. I assumed R19 for the walls and avg infiltration.

I'm fairly new to this and if I missed something significant I appreciate the help!

This still puts me at 85 874 btu/hr

kcopp

Based on....

the 24x24 slab, generally the max output you can get from the radiant slab alone in roughly 25 btu/ sq ft. So....  If your heatloss is 37K (and I don't think it is) you need a whole lot of supplemental heat.