Balancing Valves for hydronic heating

dba (aka damp head)

I'm new to the hydronic heating world and I've read a great deal regarding the use of Balancing Valves on hydronic heating.  I understand their use and importance in "balancing" a system...however I haven't seen too many in the field yet.  Are they "old" technology that are being replaced by something else or are they simply one of those things that get "omitted" as the job goes along and only added back in when the system doesn't perform as desired.

Thanks in advance for everyone's help.

Alan (California Radiant) Forbes

Balancing Valves

The only time I use balancing valves is when they come with the manifolds I buy.  I never intentionally put them in since the residential hydronic systems we install seems to balance by themselves.



I used to have about a dozen B & G Flow Setters that sat on the shelf for years.

Nick Ciasullo

Yes and No

Balancing Valves are a great idea in any system.  The larger the system, the better the idea.  Now to reality.

The reality is they are not ever used in a residential system.  Is it because they are too expensive, or is it because they aren't understood?  Possibly both.

The bottom line is that should you come across a job that has an area that is warmer or colder than the rest, the installation of ball valves can do the job.  Certainly it requires more effort as you are taking a "SWAG" when deciding how much to close the valve, and it may take you more than one visit to "dial it in" but a $5 valve that you may or may not need on any given job is a lot lower than a $40 valve that you may or may not need.  Sprinkle a half dozen of these and you have a whopping $210 added to the job.  What?

Yup.  We are going skinny because we don't want to spend the extra cash.  Did you ever get to a job that you had to drain down the entire system to replace a pump?  Same reason.  A couple of isolation valves would take us from profitable to not profitable, so it seems.

A residential system is never balanced.  Did you ever notice that the 007 installed on the 65,000btu house is exactly the same as the 007 installed on the 165,000btu house?  The general attitude seems to be that homes are small enough and the variances will not be significant enough to matter.  That is always true until it isn't.  When you have a customer that has an unbalanced home, they are unhappy.  If you don't have balance valves installed, as I mentioned, it's best guess to get it balanced.

Outdoor reset technology reduces the imbalance in mild weather.  As the weather becomes warmer (assuming we are discussing heating), the imbalance is less dramatic.  This is because the water temp in zone "A" and in zone "B" get closer, balancing with water temp instead of flow rates.  The issue isn't "fixed" with outdoor reset, but in many cases, it may reduce the need to the point where it isn't noticed - which is still a fix in my book.

I will point out that I am a Rep for B&G.  I can not by nature, be unbiased.  There is a free training video on the B&G website and if you have an hour, you should check it out.  http://www.balancevalves.com/BV-Training-Videos.asp 

The fact that you are asking leads me to believe you are looking at a home with balance issues.  Am I right?

Gordan

What about modulating valves such as TRVs?

Would the use of these obviate the need for balancing valves? Leave all circuits wide open and let the TRVs sort it out?

Nick Ciasullo

Maybe

Gordon, thanks for pointing that out.  Using a Thermostatic Radiator Valve will restrict flow in the areas that are getting too warm.  This will allow flow to redirect to the areas that aren't getting enough.  As the temperature outside becomes more extreme, these valves will need to open wider, and that imbalance may show itself once again.  This would also be true with outdoor reset.  Not so bad in mild weather, but more noticable in the extremes.

Charlie from wmass

I use them only when budget does not allow

for either more zones, TRV's, or other means to further control the heat. I like them for simple split loops. I set them when doing my firing of a new system for a client and instruct them how they work and not to touch them unless they consult me first.

hot_rod

they are always

on the plans that comes from an engineer on most jobs. The certainly increase the efficiency of piping systems with multiple loads and circuits.



Usually there is a requirement that the fluid systems are balanced by an independent contractor before the final payment to the mechanical contractor. Balancing assures top efficiency, protects the contractors and the owners, as well as assuring warranty on equipment.



On residential it is a combination of understanding the concept and benefits and cost. The differential meters to check and set some styles are fairly expensive for small shops.



There are some more user friendly styles hitting the market, and the return of large solar arrays will dictate more setters get installed, I predict.



hr

dba (aka damp head)

Thanks for info

Thanks to all for the great information....very good stuff.



DBA (aka "damp head"...I still have some time to put in before I become a "wet head"!)