New heat and hot water system

Kwakazaki

We own a small Queen Anne in Northern New Jersey (1800 sq ft), and the prior steam heat system has been converted to water. So it has black iron pipework to cast iron radiators, with relatively large diameters for the basement primary distribution. Since owning the property I have been nursing the current 1967 gas furnace, which clogs with soot and rots the burners every 2-3 years (probably running too cool, inefficient). Now the frame the carries the burners has rotted away, so its probably time to think about something more efficient. Coupled with the standard gas heating, is a standard gas fired water heater.



The current furnace is a Peerless, and the net output rating is 116,000 BTU. I ran a Manual S heat load calc, with predictably poor results for a house built in the 1870's!

On the pesimistic side, no wall insulation, no ceiling insulation and poor attic insulation, requires 96,000 BTU. If I run the calc more optimistically, some wall insulation (the reality), some ceiling insulation (the reality), R19 attic insulation (probably R11 now), then the requirement is around 60,000 BTU's. I also installed a small wood stove, mainly for family room comfort, but it can expel 40,000 BTU's, which is able to maintain the house temp in the 60's when outside temps are above 30, but I don't want to rely on this for the purpose of this analysis.



We are looking for efficiency (financial and green reasons), reliability, performance, bang-for-buck.



After doing some online research I found the Energy Kinetics site and read about their System 2000 products - sounds really cool. I also read a bunch of forum posts either trashing or talking up the products, they seem to enflame both camps views!



The EK products are way out of my price range, however:

* What do you think about the product?

* Are there other manufacturers that produce similar packaged systems?

* Is there a better system that fulfils our needs and goals?



Regards,

Ken

 

Charlie from wmass

Ken it may be the piping not the boiler

The peerless should have been piped in such a way as to hold a higher internal temperature. A good gas fired cast iron boiler with proper piping and an indirect water heater would do wonders. If it is properly sized and piped it will last a good long time. The mod cons love the low tempts they can achieve with the old radiators for out going water but many are not so in love with the iron in the water. Keep it simple and you will be happy with the results. A cast iron boiler should last much longer than yours is. Do you have photos of how it is piped in?

Kwakazaki

Photos and other

Many thanks for the advice Charlie.

Please see photos.

Not sure what you meant by " should last longer than yours"?

Its from 1967, I don't  feel cheated by a 40+ year old boiler...!

As you can see there is plenty of steam sized piping.

Regards,

Mike Kusiak_2

Converted gravity system

What you have is a converted gravity hot water system. It was never a steam system. Originally, there was a coal fired boiler which connected directly to the large iron pipes. When the boiler was fired, the hot water rose through the pipes by convection to the radiators and the cooler water returned to the boiler to be reheated.



When they installed the new boiler in 1967, they most likely added a circulation pump which is not visible in the photos. Because of the large cast iron radiators and high volume of water contained in them, the system operates at comparatively low temperatures. As Charlie mentioned, this can cause condensation problems with cast iron boilers if not piped correctly.It does not appear that you have bypass piping which would allow the boiler to operate at higher temperatures than the radiators, to avoid condensation and the resulting rusting and corrosion.



Many installers have set up systems like yours with gas fired modulating-condensing boilers which are ideally suited to low temperature systems like yours. They have achieved excellent results despite the potential problems with the old iron pipes and radiators if proper precautions are taken. Fuel savings of 25%-40% are common with this type of upgrade.



Another possibility is to replace the boiler with a more modern cast iron one, similar to what you have now. When properly installed and piped, this will work fine, but will not give you the fuel savings of the mod-con boiler. In the long run it may be simpler and more reliable, requiring less maintenance than the mod-con, possibly offsetting some of the fuel savings.



Most important is to find a good installer who can help you make the best decision on what boiler is right for you.

Kwakazaki

Piping volume

Many thanks Mike,



Another question I have is how much to change the existing pipework in the basement?



I have two drivers:

* Reduce the water volume

* Improve basement access



However, I probably would not modify the pipework at all if only one of the above were a driver.



Access is a pain in the neck, they left very large diameter pipework hanging low, which makes it impossible to think about even partially finishing the basement.



Is reducing the water volume a worthwhile thought? I assume the pipework had these reducing sizes to get the thermal lift going in the coal fired system? Which is not now a consideration with modern circulators? Is this correct? Or even vaguely close?



Regards,

Ken

EricAune

Pipe size/volume

Although access to the basement might limit how it is finished, the volume of the current system could benefit you if you were to choose a mod/con such as the Triangle tube.  Its stainless steel heat exchanger has a very low head loss and lends itself to this type of installation nicely (most times without using primary/secondary piping).



Decreasing the volume of the system, in most cases with a mod/con, will require a more complicated installation.  This due to the flow requirements of most modern heat exchangers. 



Keep in mind that the heat put into those large diameter pipes is radiating into the living space.  If left uninsulated, they are essentially an extension of your radiators.



If care is taken to properly flush the system with a cleaning agent and a in-line particle filter is installed you should be in great shape with the new boiler.