antifreeze

Unknown

Another thing that I learned from with anti-freeze in system, u must increase the size of the expanison tank! Otherwise the reilf valve gonna pop on ya....

jim_85

antifreeze

Needed to know about how much efficency you loose on a heating system when antifreeze is added to the system?

Custumer was asking & I had to tell him that I had been told that you loose around 5% eff. when you antifreeze the system but wasn't sure how accuret that was.

Brad White_63

Depending on concentration and type, between 5 and 10 percent

You are pretty close, Jim.

For discussion purposes you lose about 10 percent capacity for a given GPM/Temperature condition which can be compensated for marginally by increasing flow rate but at an exponential pumping/transport cost.

What is not discussed are the additional pumping costs due to higher viscosity and in small tube condensing boilers particularly, the banshee effect when surface boiling occurs at the contact film point.

Nick L. in Vt

antifreeze

the horror, the horror.


They call me "Hot Pipe"

jim_85

Mixture

I was told in the last cuple of years to not mix the antifreeze with the water so as not to dilute the concentration of the anti.

I don't trully know if this is good advice or just another
one of the bad ideas learnd from Dan's skool of Joe?

Brad White_63

Once you choose a concentration

uncontrolled make-up can dilute it without you knowing it. That is where the problem is. Systems should of course be leak tight. All usable glycol is mixed with water. 100% glycol is pretty syrupy and offers no advantage over a 30% or 40% or even 50% mixture which you may use conventionally.

jim_85

thanks Brad

Thats what I had thought. Just like in your car it needs to bee diluted to work properly. Plus most custumers don't like it when you quot them a price to fill the system 100% with antifreeze.

Thanks Brad.

Dave Belisle

anit freeze efficieny

The lost efficiency is in the transfer rate of the liquid to transfer BTUs out of the heating loop, not in the system efficiency as far as fuel cost are concerned . Make sure you customer knows that. Every time I get asked that question they think it will cost them 5 to 10 percent more on there heating bills if they add antifreeze. That 5 to 10 percent just goes back to the boiler ready to be recirculated and used again.

The only added energy cost as has been stated is in a longer run time on the circulator.

Pennies a week.

Dave

BP&H

jim_85

yes I under stand it will not effect the cumbustion eff.
it is the over all running eff the will be effected BTU transfer and the punp running time.I mentioned antifreeze to the customer because this is a rental unit he owns and he is going to leave the heating fuel up to the tenant and past experience tells me to save your own hide and think of the worst case ceneriol. Have found that people tend to not take care of something that doesn't belong to them as well as they would if they owned it them self.Don't want him calling me in the middle of winter with frozen pipes and to find the to tenn. has been living in one or two rooms with kerosene or electirc heaters. Been there and done that.

Brad White_65

Yes, Dave

Excellent point and distinction I should have made, that the percentage loss does not mean system efficiency, just the lesser ability to transport heat, for which compensation has to be made in the form of larger emitters, greater flow rate and done right, larger pipe sizes to compensate for transport losses.

Loss of capacity is not loss of efficiency. Cost of compensation to maintain performance and efficiency is relatively small. A burst pipe is unacceptable on the other hand!

Thanks-

Brad

Harold

Keep in mind that Glycol is sold both as concentrated (100%) and already diluted. If you buy the concentrate you need to add the proper amount of good water for the necessary freeze protection temperature. Either premix and add to an empty system or calculate/measure how much water is in the system and pump in the necessary antifreeze from the bottom, with a opening at the top of the system to let displaced water exit the system. Afterwards, run the system for a while to purge air and to mix the glycol. That is a key step for freeze control if you simply add concentrated Glycol to a system already full of water because there will be sections of the system with plain water unitl it is mixed.

Drew_2

Antifreeze Use and installation

Here are a couple of documents on antifreeze in systems and maintaining the solution.