high efficiency?

SDben

i am trying to decide between a high or low efficiency boiler. The difference is about 10 percent or an 83 vs a 93. i did the math and it seems to me like it will take about 20 years for me to start seeing savings from the 93. should i look more at the boiler itself and their respective warrantees or look at the efficiency.



The boilers in question are weil mclain, burnham, Bobcat. Any thoughts on these the bids are $8,000, $5,500,$9000.

Henry

High efficiency

You cannot use the AFUE rating on efficiency to get a REAL amount of savings. It (savings) has to do  with the system design and modulation. We get anywhere from 35 to 55% fuel consumption savings on mod/con installations. We did 9 identical apartment blocks with upt 30% difference in savings among them. The reason is the users.

If you are doing this for a home, you do not consume sufficient gas to make it a 5 year payback. The more you consume, the more interesting is the payback.

SDben

help

The boiler we are leaning toward is a Burnham 205 83% AFUE. Our current boiler is an octopus gravity system. It was in excellent condition until it cracked a week ago. It was tested at 83% AFUE. Our old (last year) heating bills for a 1908 2,000 sg ft house were Dec. $196, Jan.$286, Feb.$148,March $101. So.. do you think the new boiler would be similar.

Thank you so much for any info you can give. We are at a loss when it comes to this stuff.

CMadatMe

Don't get caught in the AFUE Trap

AFUE is like MPG sticker on a car. We both can purch the same car and not get the same milelage. When making your deicsion you shouldn't be calculating your payback based on the total cost of the higher efficiency boiler but the difference between the 2 applicances. What AFUE also doesn't tell you is that  for every 3 degrees you can run your heating system below 180 degree water you can save 1% of fuel. What does this mean? System efficiency is just as and if not more than boiler efficiency.

SDben

Hmm

Okay so do you think the Burnham 205 is a good boiler? I know this seems to be somewhat subjective but what do you think?

Do you think new systems are as good as old ones?

EricAune

New vs. "old"

Most boilers are good boilers, you will get a different answer from everyone on this one. Each contractor has their favorite, the ones they have the most experience with and are trained to install.  This question is a tough one, if you ask a large enough audience you are bound to find someone that loves it.



Not having any idea of the condition of your home (insulation, windows etc.), a 205,000 Btu input boiler sounds a little large.  Have you had anyone do a heat load calculation?  Maybe that is the size needed, but if this was sized using the label method then I would consider having a qualified contractor out to perform this very important task.  Installing a boiler that is too large will not benefit you.  Fuel savings will be realized with a modulating boiler of the proper size...every time.  If the existing boiler was over-sized then replacing it with a non-condensing model will also increase system efficiency and lower operating costs.

clammy

heat lose

i would have to agree with eric for a 2000 sq.ft. home that,s a big boiler i would recommend a heat lose be done ,at a quick glance you have about 90 btu per ft that's huge unless there old windows and no insulation if not try to get a heat lose done .Your monthly heating bills don,t look bad though.peace and good luck clammy

Henry

AFUE etc

Your boiler had a combustion test done that gave you an 83% COMBUSTION efficiency and not Annual Fuel Usage Efficiency. If you can properly size the heat load then rework the piping into a P/S system, any type of boiler will help you save. Your gas bills are peanuts compared to us up here. So, there is no point in going mod/con! For such smaller applicaitons, we have had great succes with the Raypak residential units that come with an intergrated pump and bypas.