The More Heating Zones Myth.

John Abbott

With all due respect, you make some good points but you are mistaken in some aspects and you are painting with a very broad brush. When you speak of "our industry" you are putting all of us in the same group.Nothing could be further from the truth.First of all appropriate multiple zones can and do save money whe properly installed.Buffer tanks are certainly a useful tool under some circumstances but are not always indicated.I don't understand your "over zoned"causes more fuel usage than one with less or no zones.No zones would certainly cause no fuel usage as nothing would ever call for heat.More zones do not in and of themselves use more fuel.Your point about large boilers is a good one.There is probably nothing in our industry that wastes more fuel than oversized boilers.If a boiler never shut off on the coldest windiest day of the year it is sized perfectly.In my area the majority of heating is done by oil which presents some challenges to obtain optimum efficency.Those of us who understand the laws of physics/thermodynamics are able dramaticly improve efficency.The simplest solution I have found is weather resposive controls,this lowers the standby losses and decreases the peaks and valleys of a standard aquastat.Another simple improvement is down firing your boilers you don't need to put in more than your emmiters can remove.With oil this often requires changing retention heads and static plates as well as nozzles but the gains in efficency can be dramatic.Often when using low temperature emmitters such as radiant we will put a primary circulator on the boiler so we can reset the water temps below the condensing temp of around a 130 degrees by using injection controls off the reset.I know that someone will no doubt take exception to my theory and say just use a Buderis and remove baffles to raise to get it above condensing.That certainly works but I question the thermal efficecy of sending heat up the chimney to raise stack temps.That is what you are doing when you remove baffles.Please don't take this as down on Buderis or similar boilers they wonderful equipment I just respectfuly disagree with with the methodology.In summary a great many of us can and do use multiple zones efficently we understand control strategy,Heat transfer, run fractions and proper sizing of either equipment and or firing rates.Mod con boilers are certainly efficent but where I am the cost of LP is prohibitive and 90% of our customers want oil.

John

Unknown

I hear a lot about cost of heating your home. I see a lot of systems sold in my area that have many zones. Most of these systems have large boilers and are sold to the owner on the basis that they will save money by only heating the areas they are using. While this can be true, most of these systems have no buffer tank installed and are so over zoned that the system is using more fuel and is less efficient that one with less or no zones. What I find most is that most owners see the large gas bill and turn down the heat more and do deeper setbacks and never realize what is going on.

I cannot stress enough the need for our industry to start looking closer at how we zone.

mark ransley

Zoning must also increase electric consumption alot. For my area 100w 24x7 is about 14$ a month. How about TRVs, no energy used there.

Jim_64

you are correct Sir

Talk about hitting a nail on it's head ,straight on the only big promblem is alot of HO and GC's only shop price and it seems that when your the only guy given them this information and trying to sell some thing more then baseboard ,zone valves and cheapo depo t/stat it's a hard sale ,over 10 years or more of trying to sell panel rads and i think i have about 3 custermers who i have installed them for one being myself ,it seems that supply houses also don't want to push them either maybe in another 10 years we can easly sell panel rads ,trv and indoor /outdoor reset .I just find it hard to believe that every one isn't using panel rads from my own experences the install time of a panel rad with rough in and final install was at least 1/2 the time of installing base board excluding running stat wires and zone valve install ect ,lets not get me started on water temp design also i guess maybe in the year 2525 we will finally step up and really start to embrace european conservation on engerny use and maybe some building techinques as my grandfather used to the first house the big bad wolf blew down was made to stickes maybe Grim knew some thing about buildinmg peace and good luck clammy

Unknown

Not you.

I guess I was not talking about you. The idea was the broad brush. In my area I see a lot of oversized over zoned boilers.

Supply House Rick

another nail hit squarely

as a child i remember reading national geographic about the plight of the poor in the slums of rio de janeiro, only able to make their dwellings out of sticks and cardboard. now when i drive west here to the suburbs, i see the domestic version of stick and cardboard construction. this construction is calculated to hold up just until after the final payment of the mortgage!--nbc

rich pickering

Slums

I've seen and have been in the slums or "favelas", of Belo Horizonte, Brazil, as well as walked over the mudslide buried remains of another favela -- even the worst of the builder specials are like palaces in comparison. It would break your heart to see how some people live.

Shalom & God Bless

Charlie from wmass

My issue with panel rads is stemmed from bad experiance on my first few. I installed a whole system for a family where the Husband knew the wholesaler and bought the whole system from pex to rads to Buderus boiler himself. I install the system and everyone was and is happy. I then got a few customers to place panel rads in choice locations in their homes. Of the 12 I purchased 8 had leaks. That soured me. The units had been miss handled between the factory and my job sites. I never blamed the manufacturer but I am not gun shy about using them. I feel you can over zone but it does not cause excess fuel usage(IMHO) but excess electrical usage. Over sized boilers are a whole nother debate. With the recent cold spells over sized needs to be reexamined. I have rounded boiler sizes up for people and I got 0 calls from them even in the coldest weather about lack of heat. I did have several calls for other installers systems where some zones needed to be shut off just so a few thermostats would come up to temp. I am not sure the 7 section vs the 6 section boiler would have wasted that much heat. But it would have reached design temps.

John Abbott

oversize boilers

Charlie I think I failed to express my point well.The scenario's you describe are undersized not oversized.More zones allow you to not heat unocupied areas to the same temperature as areas that are occupied.As you lower the delta T you are slowing heat transfer.your point about electrical usage is valid. Most contracters use multiple circulators to no advantage this wastes a tremendous amount of electricity and gains no clear advantage over a zone valve system with one flat curve circulator or even better a smart variable speed circ.that is controlled by delta p.circ like the wilo.
The nonfunctioning systems you desribe are the result of either insufficent flow because of piping,flow, sizing or control issues.One sectio too large does waste energy especialy on warmer days when your run fration is low.If you have Siggy's book he explains very well the relationship between steady state efficency and run fractions.If you are talking cast iron sectional boilers in your 6-7 section scenario you are wasting .Cast iron is a very dense material it absorves a tremendous amount of heat and wastes heat by emmiting more heat into a generally unheated space.The losses over years are staggering.My point is do heat losses on new systems and size boiers efficently.My own house is 3600 sqare feet and I am only running on a taco 0010 flat curve circ and firing it at 1.00 of oil per hour.I recently replaced a 6 section boiler old boiler a in an old farm house firing 2.00 gph.It is now firing at 1:00gph and it has been 20 below and windy several nights since then the home owner is warm as toast and saving considerable energy,In summary if you measure the active base board multiply it by BB output, typically around 600btus per foot and add a SMALL safety factor.

Jim_64

hey scrook

OI ! when was the last time you where belo horizonte ,i'm truely missing that place great,, beer great food and mineros are the real country folk of brazil ,cachaca and the central market even though it's a hard place to live with alot of violent crime it truely makes you apprecate the security and saftey of the united states but then again i remenber nyc in the late 70 and early 80 and i did not have any promblem in brazil and i spent time in belo horizonte ,rio,salavator and sprit of santo all excellent people peace clammy