Condensing boiler for multi temp. heating

larry

I second this approach of sizing the coils for lower temps. We did this exact thing last year with great results. Most of the time the boiler is operating in the 115F to 130F range, and since the air handler can modulate the blower speed, we never sense cold air blowing (just warm air delivered at a very slow speed with near silent operation).

andy_16

condensing boiler for multi temperature heating output.

we are in the process of renovating a 3000 sq' home, appox 1800 sq' will have radiant installed the remaining will be heated w/ hydronic coiler in the air handlers.We had planned on using a condensing boiler for the heating & hot water. I get conflicting opinions from different contractors on condensing boilers. I've been told that due to the higher water temps necessary for the hydronic coils, we won't get the full benefit of a condensing boiler.
I thought that as long as the boiler was properly sized or even slightly undersized you could expect to see a jump in effiency.
Would we be better just using a modulating boiler instead?
Any input would help. Thanks

grindog

a condensor will work great

Try to find a contractor from this site that can lead you in the rite direction. Go to the find a pro page and type in your zip.
Many heating contractors tend to shy away from boiler work that is difficult. You should find a contractor who is well rounded in there field especially when it comes to radiant heating.
There are many condensing boilers on the market and we all have our favorites. The most important thing you need to remember is that insulation is very important and you want to spend as much as you can on insulation so you can bennifit from your new heating system.

tom_49

grindog,

buenos noches mi amigo!

Dave Heath_2

Not sure if you have purchased your hydronic coils. If you have not, then have your contractor size them up with 140F Supply water temp or lower. You may be thinking that you have to supply 180F or higher. The lower design water temp to the Hyro coils will allow the boiler to take advantage of condensing. This would provide you the operational effiencies you require.

Dave_41

Condensing boiler

Just do it! Condensing boilers will condense even at the higher temps at a slight decrease in efficiency. How slight? Don't know the answer to this but after adding a coil to one system to heat a small part of the basement the HO stated that he saw little or no difference in the gas bill.
The boiler in the attatched picture is running three radiant loops, one baseboard and one coil. It has been doing this for the last three years with no problem whatsoever.
Dave

clammy

mod.condensing boiler

Andy not to show favoritism check out the virtual trade show listing and heat transfer products .There modulating condensing munchkin boilers have seperate control systems to modulate 2 to 3 temperture systems like yours and will automatic adjust water temp via a 3 way valve check it out i believe it's there vision 3 control system .You can enter your area code and locate a vision control specialist in your area to dicuss your system if your current heating contractor is unable or uninterested in your request peace clammy

andy_16

Thanks for all the advice!