high efficiency boiler replacing standard boiler

jamie_2

I'm looking at replacing my 1979 weil mclean boiler with a new munchken boiler and i'm getting different answers. Seeing how the house was designed with cast iron base boards and running temps at 180 to 190 and a 20 degree delta t i'm told the new boiler will lose efficiency to around 85% because it won't reach condensing temps. To cure this they say i'll have to add more radiation to lower return temp. Confused, please help.

jamie_2

replacing old boiler with high efficiency one

I'm looking at replacing my 1979 weil mclean boiler with a new munchken boiler and i'm getting different answers. Seeing how the house was designed with cast iron base boards and running temps at 180 to 190 and a 20 degree delta t i'm told the new boiler will lose efficiency to around 85% because it won't reach condensing temps. To cure this they say i'll have to add more radiation to lower return temp. Confused, please help.

Tony_8

get a munchkin trained

contractor or one who knows and understands condensing boilers and outdoor reset. Links to contractors are found on the left of this page.

Floyd_5

Whoever is telling you this.....

doesn't know about the condensing, mod. boilers.... find someone who does......
Look down at the "Ultra" thread and watch here for awhile and you will see that what you have heard is all wrong.
Those boilers will get a min. of 90+ eff. even if they aren't condensing...AND... MOST of the time they will be condensing because you ONLY have to run those high temps. for a few days out of the year......

Just don't make the mistake the guy did in the Ultra thread...find someone to install the boiler who knows what he is doing.....

paul lessard_2

you can't go wrong

with a munchkin and cast iron. DO IT !

Mark Hunt

Here it all the time


The cast iron radiators in your home were sized to deliver enough BTU's to the space during the COLDEST days of the year with the HOTTEST water the boiler could produce.

During the milder seasons, spring and fall, those radiators probably don't get warmer than 120 degrees because they are large enough to satify the demand with lower water temperatures. So the system as it sits right now is ALMOST resetting itself already.

The math here is very simple.

A 2000 sqft. home that loses 50,000 BTU's per hour when the outdoor temp is -10 may only lose 20,000 BTU's per hour when thet outdoor temp is 50 degrees. (This is assuming an indoor temp of 70 degrees)

A modulating boiler with an outdoor reset will be able to tell how much heat the home REALLY needs an adjust it's firing rate accordingly. So on the 50 degree day it becomes a 20,000 BTU boiler and as it gets colder outside, it gets bigger.

The standard on/off boilers will fire at the max rate EVERY time they fire, regardless of what the home truly needs.

Talk to a different contractor.

Have you tried the "Find a contractor" on this site?

Mark H

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

heatboy

Two things have two be done.

The first would be to do a heat loss estimate on your home. Once that is done, all of the radiation must be measured to calculate the outpu at various water temperatures. If the radiation numbers point that the maximum water temperatures at design outdoor are 150°F, or so, bu all means utilize a condensing boiler. If the radiation must be run at 170°F, it may be advisable to use a standard boiler then add a reset control system and either a mixing valve or variable speed pump to attain full radiation reset.

This is a choice you can't make until the preliminary designs are done. You will probably, or should, have to pay for this design service. It is money well spent if you can find a contractor you trust. THAT could be your toughest challenge.

hb

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

Tony_8

surprised me

someone sold him that Ultra in the 1st place. That's how bad raps get started.

munchkin-man

Munchie and cast iron

A match made in boiler heaven. As stated it will condense. The key will be primary secondary piping and a pump sized to the piping. The vision one control will provide out door reset as mentioned in this string. for more info go to manufactures in the pipe at the top of the page and then to heat transfer products to get to the web page. e me at the address above with any questions. And as always gentalmen thanks for you suport.