What to do when you do not know a system's vol

George_10

Here is the scenario. You go out on a service call on an existing system, either hydronic radiant or hot water. The system obviously needs TLC. But there are no details as to how big the system vol is. We have developed a simple way to get that elusive answer. I will be putting out more about this in the next two weeks.

For now I just wanted to see if there is any feed back about this idea as to need or would such a service be helpful.

Dana

I'm not sure, but would love to see your equations.

bobby7388

I wonder

if you use the system running pressure to calculate lbs lift to gal's?

It is a reach but could get you in the ballpark.

George_12

What is the differece between hydronic radiant system and hot water system? Thank you George.And,yes I whould like to know the equation/solution to the problem.

Mike Kraft_2

Assuming volume?

I'm thinking you are meaning water content.The only way I know is by isolating zones,pipe sizes,appliance content and emitters.I deal only with residential so high rise/commercial is a horse of a different color.Getting the tape measure and doing the math and conversions.In a radiant job count loops,look for tubing footage history.If this is not available then count loops and check centers and  '.Convert to gallons.You have an easy way........interested:)

cheese

Dave Stroman

You take an air commpresser and "purge" the water out of the system with air pressure. Simply count the number of 5 gallon buckets that you empty.

Dave in Denver

Mark Eatherton1

Sodium Titrate

From an article I wrote a while back...

You can estimate fluid content in a number of different ways.

First, you can force-purge a heating system into a large container using compressed air and record the number of gallons you removed. This is a guaranteed way of determining the system’s fluid volume, but it is quite labor intensive and can be messy.

Another way is the sodium titrate method. With this method, you test the system for residual parts per million of sodium. Then you completely mix 5 lb. of salt into a 5-gal. bucket of water and pump this saline solution into the heating system. Allow it to circulate for at least two days, then perform another sodium titrate test.

The incremental increase in ppm will tell you how many gallons of fluid are in the system. This method is tricky inasmuch as very few technicians have access to titrate testing equipment. This type of testing is typically performed for free by water treatment chemical companies. Call your local water treatment company for details.

The third method works quite well with new systems but is no more than an educated guess in existing systems.

I have developed a spreadsheet using standard volumetric values for standard nominal tubing sizes from 3/8-in. through 2-in. The spread sheet calculates exactly how much fluid is in the system based on the linear feet of tubing in the system, plus the boiler’s volume.

Once this quantity is known, an accurate approximation of the glycol necessary can be calculated and the appropriate gallons of antifreeze purchased and taken to the jobsite.

A fourth method is to draw a sample of the glycol/water mixture and send the sample to the glycol manufacturer. It can tell you exactly how many gallons of glycol would need to be induced back into the system in order to bring the fluid up to a given percentage.

In order to properly fill the heating system, there must be a means of injecting the premixed glycol/water solution into the heating system, and a place for all of the air-entrained fluid to return back to your charging system. This basically requires the designer to install an additional drain cock, which is actually used as a fill port. This fill port can be incorporated into the make-up part of the system. The purge port can be installed in its usual position.

My friend and associate Robert “Hot Rod” Rohr reminded me that if you are using a boiler drain valve backwards, as in a fill port application, you might want to consider using a standard ball valve with a male hose bib adapter in lieu of the drain cock. The reason is that if you try to stop flow backward through a drain cock, it will strip the bib washer right off the screw. Boy, howdy, have you got problems now! Thanks, Hot Rod.

A word of caution here. If you have a heating system filled with glycol, it is not a good idea to leave the make-up in an automatic fill position. If something goes wrong, and the system starts taking on fresh water without being noticed, you will dilute the glycol to the point of having no freeze protection at all.

This won’t be noticed until it’s too late and the system has already frozen and can no longer provide heat. Unfortunately, in some cases, this can lead to additional freeze damage of the domestic plumbing systems.

The full article can be read at http://www.contractormag.com/articles/column.cfm?columnid=113

Am I close?

ME


To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

jerry scharf_2

Ion titrates

ME,
A couple thoughts from my dusty past.

Instead of lab testing the water, what about using an Ohm meter that can go to 20 Mohm or so. Clean a glass cup really well and rinse it with DI or distilled water. Take a sample and read the resistance. Then add the ions of choice (NaCl is a favorite,) mix and remeasure the resistance. It should decrease with the increased ppm of ions. It's not linear, but it's a simple curve. The biggest problem with the is the required cleanliness to have a useful measurement.

There are thousands of things to add, chemical reaction to use and ways to measure. Each time I thought about it, more ideas kept popping up. It all comes down to add a known quantity of something, mix and pull a known size sample of the mix.

Now I'm waiting to see what real chemists have come up with.

jerry

George_10

Just the way I keep things straight

Hydronic radiant I think of as in floor tubing radiant. Hot water systems are other ways such as baseboards, hot water radiators, and wall and ceiling panels. All are closed loop and I realize they are all forms of hydronic heating, but it helps me when I am talking to a contractor to better visualize their system they are discussing with me. They also seem to have different water chemistry problems. That is my reasoning and it is useful to me to help with solving their problem. As you correctly stated, there is no real difference as far as it being radiant heat.

George_10

Next week I will put this method on the wall

We are working out how we will implement this service.

I will post the complete method that we have developed.

We have suggested before the methods that you folks have mentioned, and we just felt there had to be a better way.

We have it and I will post all of the details after I return from Loveland Rad Fest. We just want to insure that we can maintain our offer in the future, which will also be part of the details.

See some of you in Loveland and I will be posting next week
a much easier way to come up with Vol of an unknown system.

Kal Row

question is why do you need to know \"exactly\"?

a guestimate using ziggi's software (or pipe vol tables) is more than good enough, for modern expansion tanks or for glycol or additive mixes

George_10

Many contractors have told me that

they show up on a service call on a system that they know nothing about and there is no written info on the system.
They can not see zone tubing as it is buried in concrete.
They are in need of some Vol figure to add glycol, clean and treat a fouled system, etc.

This was the reason that we started thinking about this problem.

Robert O'Connor_6

Very cool

Good marketing stategey and I await your revealation!

Regards,

Robert