Cold climate guys, do you always antifreeze your hydronics?

PaulWojnicki

I have only done a few systems with PG, all about 50% concentration.
Snowmelt and Garage heat.
I have using in combination Aluminum, copper, cast iron, black steel, brass, chromed brass, stainless steel and Pex tubing with compression with O-ring and clamped connections. Soldered and threaded pipe connections, always used teflon tape and pipe dope. I like and use Spirovent Air Eliminators on all my installs. I flushed the systems with 3 different brand cleaning chemicals over the years prior to adding the PG. I never got the green blue fuzz on my installs. I have seen it on other installs some worse than others. No pumping problems, heats spaces, pond water, and snow melts. I've used plate and tube style heat exchangers. My snow melt systems have manifolds installed in under ground landscapers sprinkler plastic boxes. I would imagine it can be pretty cold in those boxes with the loose fitting lid at grade. Time will tell.

xmorganx

Antifreeze is the devil. To be played with only if absolutely necessary. Messes up your pump calculations. Expensive extra components. Serious risk of bacteria and early corrosion. On a snowmelt without constant circ ok, but otherwise stay far far away....

GroundUp

xmorganx said:

Antifreeze is the devil. To be played with only if absolutely necessary. Messes up your pump calculations. Expensive extra components. Serious risk of bacteria and early corrosion. On a snowmelt without constant circ ok, but otherwise stay far far away....

Please, elaborate....

Zman

xmorganx said:

Antifreeze is the devil. To be played with only if absolutely necessary. Messes up your pump calculations. Expensive extra components. Serious risk of bacteria and early corrosion. On a snowmelt without constant circ ok, but otherwise stay far far away....

I am going to have to go ahead and, disagree with you on this one.
If you have one of the needs laid out in the intelligent posts above:

• Adjust your pump calculations
  
• Buy whatever expensive components you need (not sure what those are)
  
• Isolate the system from potable water.
  

Do you seriously install snow melt with straight water and count on the circ to prevent freezing?

meticulousmike

i only used glycol once in a student ghetto house..the stupid kids left the back basement door open when the boiler was down and the pex froze everywhere and the guy who installed it cobbed the piss out of it.it had hanging drooping loops going in every direction, i don't think he fastened them anywhere..we need a baseboard in this room ;sure we'll just tap a loop in the supply side or return side..what a mess! anyway not knowing how much to pump into the system ,i just pumped most of it in.who cares..the guy didn't hire me to install or troubleshoot it when it was down he just had too many inexperienced people involved in it including myself back then..i was learning real quick though if i wanted to make some money.my question and opinion is .if eth glycol can be used in cast iron or aluminum engine blocks and heads.mine is alum to cast and by putting your 50/50 mix in doesn't and isn't it not supposed to corrode ?that's the whole point you can't run a car without it,it will corrode,boil and freeze if it's cold..a radiator today is made of cheap plastic to aluminum or maybe brass,my old car has an all brass.i think i've seen all copper or copp/brass mix.what's in a boiler? cast iron to copper to cast to galvanised steel or black pipe..i've seen too many with black pipe.ph balance change over time can cause corrosion if not maintained?.the only thing i get when i don't change the AF is breakdown of lube and seal conditioner causing my pump to squeal or weep and worst cases needing replacement but never freezing ,boiling or corrosion..

mattmia2

automotive antifreeze has inhibitors in it to keep the aluminum from dissolving in the hot water. Old cars with cast iron blocks and heads and copper/brass radiators and heater cores could handle plain water but newer cars even without aluminum components would have issues with the coolant getting hotter than the boiling point of plain water at the radiator cap pressure partially because of higher temp thermostats to run the engine hotter to reduce emissions.

CBRob

On the subject of leaking glycol.
I've got a snowmelt system with around 45% glycol that has a really slow leak at the threaded connection to the boiler return.

 I'm going to try the dope and tape combo...

Anyone else have a go to preventer for leaks here?

GroundUp

Anything anaerobic. Permabond LH050 or LH150. Loctite 565,567,577,etc. Superdope. All awesome for threaded joints. Kinda messy, but you'll never have another leak again

CBRob

Cool! 
Never looked at Napa for boiler install supplies

GroundUp

Me neither, it's on the shelf at the plumbing supply house

CBRob

Never been in a plumbing supply house before.
Only loc tite I've seen was auto grade. They also did the anaerobic stuff.
Thanks again.

pecmsg

CBRob said:

On the subject of leaking glycol.
I've got a snowmelt system with around 45% glycol that has a really slow leak at the threaded connection to the boiler return.

 I'm going to try the dope and tape combo...

Anyone else have a go to preventer for leaks here?

What type threaded connection. Plastic, steel, copper, brass, combination of all?

ChrisJ

@mattmia2 My last two cars had 20 PSIG systems which gives 260F+ boiling point even with plain water. I think antifreeze only increases it 10 degrees or so while decreasing how much energy the water can transfer.



When is antifreeze actually required for a properly working heating system?
Is it only for intermittent use? I would assume any normal running system should in theory never drop that low?

mattmia2

Modern automotive cooling systems long ago stopped be constructed such that they could run plain water. Aluminum dissolves pretty readily in hot water.

ChrisJ

mattmia2 said:

Modern automotive cooling systems long ago stopped be constructed such that they could run plain water. Aluminum dissolves pretty readily in hot water.

GroundUp

ChrisJ said:

When is antifreeze actually required for a properly working heating system?
Is it only for intermittent use? I would assume any normal running system should in theory never drop that low?

Obviously dependent on the area, but when folks are only keeping their garage at 40* and a pump or thermostat dies when it's -40F outside, it can be frozen in minutes without antifreeze. I get at least a dozen calls every year for frozen garage loops because people are either scared of antifreeze or too cheap to buy it

ChrisJ

GroundUp said:

ChrisJ said:

When is antifreeze actually required for a properly working heating system?
Is it only for intermittent use? I would assume any normal running system should in theory never drop that low?

Obviously dependent on the area, but when folks are only keeping their garage at 40* and a pump or thermostat dies when it's -40F outside, it can be frozen in minutes without antifreeze. I get at least a dozen calls every year for frozen garage loops because people are either scared of antifreeze or too cheap to buy it

That's the part that confuses me.

"Use antifreeze only when you must".
Yeah, but the time when you realize you must it's too late. Isn't it?

Sort of like buying fire extinguishers.

GroundUp

@ChrisJ right. I get that glycol requires maintenance (so does water) and reduces heat transfer (unnoticeable in a properly designed system), but it's "taboo" for too many people simply because they heard someone else say it IMO. The only argument worth any salt, to me, is the higher pumping power required- even though it's pennies per month in most cases. I always give my clients the option, and literally all of them opt for glycol if I recommend it due to the aforementioned "what-if" scenarios. Radiant slab in a basement when there's forced air for upstairs and redundant? Then no. I will still give the option but don't necessarily recommend it. Radiant slab on grade garage/shop/barn typically kept below 60 degrees? Absolutely, 1000% recommended. Slab on grade home always kept 70+ and fully occupied? Again, optional, but I still lean toward glycol if there's an attached garage. Vacation homes/cabins, always recommended. I really don't understand why everyone is so scared of it, but I guess it keeps me in business fixing frozen loops and selling glycol.

CBRob

On the subject of leaking glycol, 
anyone have a trick for removal of the blue stain left behind
I've got a spot on a epoxy coated garage floor I'd like to remove.

CBRob

Noticed that triangle tube required a pH range between 6 and 8

Most of the cryo tek products are 8.5 to 9.

I'll be sure to go with the universal or aluminum spec stuff for triangle tube.

I was surprised to see a pH that low speced out.

CBRob

pecmsg said:

On the subject of leaking glycol.
I've got a snowmelt system with around 45% glycol that has a really slow leak at the threaded connection to the boiler return.

 I'm going to try the dope and tape combo...

Anyone else have a go to preventer for leaks here?

What type threaded connection. Plastic, steel, copper, brass, combination of all?

This is the supply to a triangle tube boiler. Brass into copper threaded.

hot_rod

If you go the glycol route, it must be used in a cleaned system, use a hydronic type cleaner first.

Blend only with DI water, or buy pre-blended.

Avoid over-heating, stagnation in solar thermal really destroys glycol quickly, ph plunges. It can over heat in hydronic systems when the pumps are undersized, not providing adequate flow thru the boiler for example.

Test yearly or every other year, boost ph if needed, use the manufacturers boost package.

If you follow these manufacturers recommendation and have a leak free system, glycol should last 10, 15 or more years.