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Hydronic Baseboard: Antifreeze v. H2O

skibum7's picture

We just purchased a new townhouse in North Central VT. It has hydronic slab and baseboard heat - currently running H2O. I'm trying to get a handle on the pros and cons of adding antifreeze to the system, and, like researching medical things on the net, my level of confusion and paranoia are now about 50x what they were when I started this "drive myself nuts" research project.

A few items:

Property is Energy Star Rated (5 star), brand new, interior (not end) unit, has pex tubing, and Runtal baseboard. I haven't the boiler/pump manufacturer & models at the moment, but will be getting that info this coming weekend. We're loving the system - efficient seeming, and absolutely whisper silent. The property is a second home for vacation purposes.....utilized for weekends and vacation weeks throughout winter season, with periods varying from 4-15 days where we're one state away.

So should I just relax and enjoy.....or should I create a strategy in the event of some 4 day power outage due to a January ice storm where it's 10 below for a week. Does the boiler use electricity to work ? I'm assuming the pumps do. Any experience or thoughts would be appreciated....as well as links that might actually discuss this issue. I'm going to run all this by the plumber and builder, but I thought I'd get outside thoughts as well.

How about keeping the water and getting a generator to keep it all going in event of power failure ?

You see, I'm nuts !

Anyways, thanks in advance for any assistance.


Edited 11/5/2006 8:46 pm ET by skibum7

(post #113572, reply #1 of 12)

is the boiler the source of your hot water also...


yes the system uses electricity to function.. the boiler, zone valves and pumps...


 


 


Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!! What a Ride!


Forget the primal scream, just ROAR!!!

"Some days it's just not worth chewing through the restraints"

(post #113572, reply #2 of 12)

There is a 50 gallon hot water heater separate from the boiler that I assume is for our sinks, showers, etc.

(post #113572, reply #3 of 12)

does the boiler heat that water in the seperate tank???

 


 


Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!! What a Ride!


Forget the primal scream, just ROAR!!!

"Some days it's just not worth chewing through the restraints"

(post #113572, reply #4 of 12)

As a general rule, 50/50 antifreeze around here. It does not perform as efficiently as a heat transfer agent as water does. But peace of mind is worth something.

Antifreeze needs to be changed out every year ort two to avoid orrosion in some fittings, but I have been told that there are some fittings and valves that resist this...

In slab and runtels base heaters

Great comnbo!

 

 


Welcome to the
Taunton University of
Knowledge FHB Campus at Breaktime.
 where ...
Excellence is its own reward!

 

 

Oh Well,

We did the best we could...

(post #113572, reply #6 of 12)

unless he has domestic HW...

 


 


Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!! What a Ride!


Forget the primal scream, just ROAR!!!

"Some days it's just not worth chewing through the restraints"

(post #113572, reply #5 of 12)

Being a townhouse, I assume some rules from a homeowners association or such like that might limit your options for a generator. You might want to check that out before investing

 

 


Welcome to the
Taunton University of
Knowledge FHB Campus at Breaktime.
 where ...
Excellence is its own reward!

 

 

Oh Well,

We did the best we could...

(post #113572, reply #7 of 12)

I had a house built on the northern border of NY, which is actually a bit further North than you.  The contractor who installed the radiant floor heat for my shop was also an anal engineer whose company installed over 1,000,000 feet of radiant tubing.  So he appeared to be knowledgeable and experienced.  He recommended to definitely use antifreeze.  Just a couple of years prior we had the great ice storm which knocked out electricity for a couple of weeks.  With a long electricity outage, or even a breakdown of the system, the entire system could freeze, so antifreeze is very wise protection.  Imagine the damage if piping froze in your slab.


Antifreeze produces a small decrease in heat capacity, but if the sizing is done properly that's taken into account.  If formulated for heating systems they also contain corrosion inhibitors and oxygen scavengers which extend the life of the system.


The antifreeze used has a propylene glycol base which is much less toxic than one with an ethylene glycol base.  Ethylene glycol is used in vehicle antifreeze, propylene glycol is used in potable water systems such as in RV's, because the slight residue remaining after flushing is not harmful.

(post #113572, reply #8 of 12)

If you want peace of mind, go with the glycol. Pex that is buried in concrete will bust if the water freezes. 


 Can you guarantee that someone will turn on the generator and moniter it if the power does go out?


If the power does go out for any length of time, you will have to drain the water lines and the water heater.

(post #113572, reply #9 of 12)

http://www.heatinghelp.com/pdfs/235.pdf

I found the link above last night. An interesting read. The general thinking seems to be avoid anti-freeze if you can...but think carefully about using it especially if you're a vacation/occassional visitor.

I'm planning on researching "mission critical" electric generators further (I think I could get permission of homeowners board for a discreetly placed unit). I also neglected to mention there is a direct vent fireplace (furnace, basically) that works with no dependence on electricity in the corner of the first floor (layout is ground floor slab, 1st Floor Runtal baseboard + DV fireplace, 2nd Floor has bedrooms/baths with Runtal baseboard). That baby kicks out incredible heat and would be a good backup during an outage.

I also do have caretaker access for someone to turn a generator on in event of major outage, and I'm a 5 hour drive away. I'd be able to go there if something major happened

I'm also wondering if they make generators that can be installed in the enclosed mechanical room inside (we have some space there) and direct vented, vs. having to be installed outside.

I am actually liking the idea of a generator based solution....which would allow all the plusses (efficiency / wear & tear / ease of maintenance) of using water only in the hydronic system, but protection in event of major power outage event during the Nov. to April cold season.

I am appreciating all the good the input here, and welcome additional thoughts.

(post #113572, reply #10 of 12)

If you're just interested in keeping the heat and two light fixtures going during power outages, the boiler and related equipment would draw a very small amount of electricity - so the generator would also be very small. A natural gas, permanently mounted unit (something small like this http://www.guardiangenerators.com/Products/Residential/GUARDIAN/GUARDIAN7kW.aspx ) might fill the bill.

(post #113572, reply #12 of 12)

Thanks for the input. I will be meeting with a contractor specializing in generators...and will be interested to learn his thoughts.

Now if they just had a LP emergency generator the was smallish and installed safely indoors....I'd be psyched. The outdoor units are all a bit big-ish.

I'm also thinking about a portable unit that would connect to a manual transfer switch. Park it in the garage and wheel it out. But that would need gas by the gallon, unless there's some way to connect to the LP service in the townhouse.

Anyways....I'm learning more, trying not to be paranoid, and will see what options seem to make the most sense. Balancing paranoia with realistic probabilities.

(post #113572, reply #11 of 12)

Read your insurance policy. 


Increase coverage if damage due to freeze up is not covered.


Make sure policy is paid before winter.


Sleep like a baby