Should I replace my old boiler?

Hey_Obie · March 2010

I have an old HB Smith oil fired boiler that has been in my house when I bought it 23 years ago. And I do not know how long it was in place before that.

The boiler has given me no trouble, but the price of oil is making me look at replacing it. I had a local HVAC company give me a price to replace it and the salesman said that I would probably save 50% on my oil bill by switching to a new furnace. I really doubt that. The effieciencies of oil boilers has not improved that much (gas maybe, but not oil I think).

The old HB Smith is a BB14 and the burner has a nozzle size of 1.35 and generates about 140,000 BTUH.

The new unit would be a Buderus G215-3 which is 86% efficient.

Any thoughts on the gain of efficiency is appreciated.

Thanks,

Obie

Robert O'Brien · March 2010

You

would see substantial savings. How did you arrive at the size of the prospective new unit?

Big Ed_4 · March 2010

What Robert is getting at......

To properly size a hydronic boiler for heat you need to know how much your home looses on the coldest day of the year ... The envelope of the building looses a certain amount of BTU's an hour per ten degree outside temperature drop ... This is found through a heat loss calculation .… Then match your number to the boiler net ... You will be surprised how little you need ... Why buy a Mack truck to go grocery shopping ...... Less is cheaper . Don't be afraid buying a small boiler ... That boiler you are looking at I installed one in a 6000 square foot 1920 's no insulation summer home here on Long Island ...

Add the 2107 Logamatic control too and you may cut your bills in half and will also increase comfort of the home ... The outdoor reset follows the heat loss through temperature ... As the outside temperature drops the boiler temperature increases ... The control follows your heat curve besides manages your system ... Lower the boiler temperature , the less the system loss ...

Comfort comes from a very even heat ... No more large swings in room temperature . That uncomfortable Hot/Cold feeling ... No more hearing that expanding and contracting pipes noises either ...

Oh , over the years installing these units and coming back for service , I hear and can calculate though the hour meter of the Logamatic the large savings of these systems ... Yes they are well worth it at $3 per gallon @todays Prices ...50% is not far fetched... Think ahead ... Think smart ...

Also those high numbers you seen on Gas condensing boiler are only achieved on low temperature radiation systems , Large massive radiators and radiant heating ... And most of them are controlled by outdoor sensors ...

bob eck · March 2010

new boiler

if you are staying with oil look at the burnham MPO series 87% AFUE with their alliance indirect water heater.

if going nat gas look at triangle tube prestige solo with their smart indirect water heater or their prestige excellence boiler with built in indirect water heater 95% AFUE qualifies for federal tax credit plus some states offer tax credit and some utilities offer a rebate check it out.

I replaced a 33 year old weil mclain 3 section oil fired boiler with domestic coil for hot water that used about 900 gallons per year. oil bill would have been almost $2100.00 this year.

I installed a triangle tube PE110 prestige excellence nat gas 95% AFUE boiler with built in indirect water heater and my gas bill for heat and hot water will be just under $1000.00.

Triangle tube prestige boilers are available in LP gas.

If I put in a new oil boiler I would have had to put in a stainless steel chimney liner plus new oil boiler plus indirect water heater. Plus with a MPO burnham oil boiler I would not get the federal tax credit.

If you are staying with oil make sure your chimney is good or get a stainless steel chimney liner installed and you need to take a look at your oil tanks. How old are they will they need to be replaced now or in a few years.

k_2 · March 2010

re

had a GB125BE installed in december and it is purring right along. Why not do that and get the tax credit.......doesn't quite make up for it but it is quite a piece of gear

Hey_Obie · March 2010

Gotta get the right size

As far as sizing the unit, it is beyond me. I think the HVAC guy just went with a comparable size. He probably makes more off a larger unit. If anyone could tell me the number of BTU's I could get by with, I'd appreciate it. If I could get the nozzle size down to 1.0, that would save me a lot of oil compared to 1.35 if it can keep up Let me describe my house, and it is not simple. The house was built in the 1890's. The original house has the oil fired boiler. Each room has in it what I would call first generation baseboards. The piping is steel with Taco Venturi valves Let me describe the baseboard. Inside, it has three copper tubes (they are oval) about the size of 1/2 copper pipe. The three tubes run through copper fins that are 5 inches long. On the outside, each baseboard is 6 inches wide and 20 inches tall and the length varies by room. The first floor is 750 square feet with a total of 20 feet of baseboard (and it isn't enough). The second floor is also 750 square feet with 34 feet of baseboard (good fit). The attic is about 700 square feet of usable space with no heat. The windows in the old house have been replaced. I insulated the roof in the attic but most of the old house is not insulated. I put on an addition 15 years ago which I heat with a heat pump with electric backup. I just bought and installed a 18 by 18 by 3 water to air heat exchanger at the air handler that I am going to connect to the boiler. Instead if electric backup, I am going to change it to open a zone and let the water heat the addition. The addition is 1000 square feet. I live in the country so gas is not an option. I have two 250 gallon oil tanks inside the basement and they are in good shape. I relined the flue about 6 years ago with flexible stainless steel and I poured a vermiculite mortar mix around the pipe. My old boiler has tankless hot water and I love it. I played with the piping a little so that the tankless goes into my 80 gallon electric water heater in the cold months. The electric is just a warming station and the oil does the major heating. It works beautifully. In summer, I am all electric. I burned about 650 gallons of oil this year. It was a very cold and long winter in Maryland. I also burned a cord and a half of wood in my small Vermont Casting stove. So that is my story. The house is insulated a lot more than when the original system was put in, so it may be oversized. Thanks for helping me guys. Help me size this thing Thanks Obie

Big Ed_4 · March 2010

Heat loss Calculation

Sounds like convector radiation .. But copper fin ?

Need to measure and note envelope the of the building (what is exposed to the out side ) To find out your heat loss ,sketch the floor plan , Measure the out side walls H&W and "R" value , measure the outside windows and doors , note their type , single with storms , double pain , wood , metal .. Subtract the windows and doors for the net wall ... measure ceilings exposed to attic or weather like a vaulted or cathedral , figure their R value (thickness of insulation ) , Sky lights figure and subtract too ... Floor space , slab or over ventilated space .... Then figure the cubic footage of the interior ....

Now go on line or go to the library to figure your heat loss ... I still use the book but can be found free on line....

Should I replace my old boiler?

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