Efficiency???

Richard Miller_2 · May 2003

Dave_13 · April 2003

Boiler Efficiency??

I am going to upgrade the heat and Hot water system in my home in Buffalo, NY in the near future. Currently, I have all electric. Yuckk!!! I've researched alot of these high efficiency boilers (Munchkin, Viessman, Trinity, etc..), But what is the payback on these extra expenses over a conventional boiler? And do they have the life expectancy? Whould hate to replace them every ten years!! Any opinions? Thanks alot and god bless America!!!

Roy Collver · April 2003

Pay Back

Pay back is such a moving target these days that it is difficult to give any reliablle number. The price of fuel continues to rise dramatically and we are unlikely to see it return to the levels we have enjoyed in the last few years. The more energy a building uses now, the faster the payback period usually is. The easiest way to come up with some kind of number is to compare the AFUE rating of each appliance and calculate an energy cost based on past energy use. In your case, you will have to translate kilowatt hours into Btuh in order to make any kind of accurate comparison. AFUE is only part of the picture however and system efficiency can change dramatically with the type of terminal units you use (baseboard vs. radiant floor for example - different water temperatures required) and the way a system is controlled. Pretty tough topic to deal with on the Wall. Can anyone else out there recommend some reading material on this topic?

BillW@honeywell · April 2003

Payback

Let me start by saying that yes, the efficiency of your heating/cooling system is important, but it is only part of the picture. Energy costs are the third largest expense (after taxes & mortgage) that a homeowner will have to consider. Think of your house as a system! One component of the system has a direct effect on the other. The efficiency package has to include attic & wall insulation, roofing and ridgevents, windows, housewrap, house design, what type of heat delivery system you choose, what controls it, and what accessories it has,like programmable thermostats, zoning and humidification. Landscaping is a factor, with trees or shrubs to provide summer sun relief or block winter winds. Don't forget the water heater, the refrigerator/freezer, and the lighting. Look for "EnergyStar" rated products. "EnergyStar" means that the product has passed a series of tests by the federal EPA, and they are proven energy savers. Contact a local heating professional, or use the "Find a Contractor" feature above. Make sure they do a full set of heat loss calculations! To generalize, it pays to buy the most efficient products that your budget will allow, and to stay in the home at least 5 years to gain any paypack. I hope this helps you in your decisions.

BillW@honeywell · April 2003

Payback

Let me start by saying that yes, the efficiency of your heating/cooling system is important, but it is only part of the picture. Energy costs are the third largest expense (after taxes & mortgage) that a homeowner will have to consider. Think of your house as a system! One component of the system has a direct effect on the other. The efficiency package has to include attic & wall insulation, roofing and ridgevents, windows, housewrap, house design, what type of heat delivery system you choose, what controls it, and what accessories it has,like programmable thermostats, zoning, humidification and outdoor temp reset. Landscaping is a factor, with trees or shrubs to provide summer sun relief or block winter winds. Don't forget the water heater, the refrigerator/freezer, and the lighting. Look for "EnergyStar" rated products. "EnergyStar" means that the product has passed a series of tests by the federal EPA, and they are proven energy savers. Contact a local heating professional, or use the "Find a Contractor" feature above. Make sure they do a full set of heat loss calculations! To generalize, it pays to buy the most efficient products that your budget will allow, and to stay in the home at least 5 years to gain any paypack. I hope this helps you in your decisions.

BillW@honeywell · April 2003

Sorry

I hit the button twice!

UniR · April 2003

Tough Call

Dave, you really have to crunch a lot of numbers to do the analysis.

You have to estimate your delivered fuel costs, both short term and long term and who knows how fast things are going to go up. Then you need to factor in overall efficiencies of different solutions and include your DHW since it is likely around 15-25% of the total amount.

You also need to have an idea of how much it costs to heat your home. This is difficult since your heat is part of all of your electrical consumption. If you don't air condition then you could compare winter to summer bills. From this you can ballpark your electrical consumption. Estimate the annual KWH and then multiply it by 3400 and you have the net BTUs that you are going to have to create from NG or oil. A manual J will help you size your system, but this will help you calculate your savings. This assumes that your electric heat is near 100% efficient and that you are going to keep your house at roughly the same temps (otherwise factor for it). Do this for the water heater as well but use 90% or 80% if it is an older water heater.

Now comes the fun part. Take your proposed solution and break it down by boiler, DHW, oil tank or gas lines, distribution and rads, pumps and expansion tanks, flue and vent, controls. Take the estimates including installation "and artwork" and put it into these categories. Next put in estimates as to how long these various categories should last. Piping 50 years, DHW 20 years etc. Get whoever is quoting to help you on this.

Now take the overall estimated efficiency (is AFUE the best guess? I dunno but what else is there to go on) and divide the annual BTUs by this efficiency number. This is how much fuel you'll need. I'd use 90% of the boiler efficiency to estimate for a DHW solution. Add this together and include any annual cleaning costs, the $10/month charge for NG... anything like that. Also, estimate any costs you'd need for your current heating system if you kept it and the life left of it. It should last quite some time.

Still with me? Take your current annual electrical consumption for heat and water and multiply it by your best estimate of what electricity will average in cost over the next 5 years or so. Add to it the annualized cost of what you need to fix it. Now compare this to the BTU load divided by efficiency (to make it the number higher) divide that by 10,000 to convert it to gallons and multiply it by the fuel price. About 1000 to get it to cubic feet for NG. Add to those costs each category of installed cost divided by the estimated life for of each category. If the proposed solution is more expensive per year, there really is no payback. This is your best calculation. Compare the annual costs of all the solutions and keep in mind the quality of your contractor and the equipment.

For the actual payback calculation, take the investment costs (less anything you would have had to spend on your current system) and divide it by the old fuel cost less the estimated new fuel cost. One caveat is that this does not factor in the life of the parts and nothing lasts for ever except old inefficient cast iron dinosaurs. Want mine?

Note these formulas do not take into consideration things like comfort, quality of service, greenhouse gas reduction, snob appeal etc. but it does let you know if it is a good economic decision for you.

To further complicate this, the building envelope must be considered as part of the system as well. It isn't very likely that a high efficiency Viessmann will rank very high in this but the entry-level models should. The Trinity may score well but how long would you estimate its useful life at versus a Buderus or Smith?

Have you currently got a need for NG for anything else or a place to put an oil tank?

Dave_13 · April 2003

Uni,
well that pretty much blew my mind!!!! I just bought this house and knew from the beginning that I wanted yo get rid of electric heay & HW. Probably will go with propane since there's no gas up here. Thanks for the formulas. I plan on staying here for at least 15 years, so it's probably worth the high effic. I wonder if they'll last like an old boiler????

joel_4 · April 2003

propane

You should think twice about propane. Here in Mass since it has lower BTU per gallon and cost more per gallon than oil it costs typically TWICE as much to heat a house with propane as it would with oil!

Troy_3 · April 2003

High efficiency?

Dave we install both Munchkin and Viessmann boilers. Have both in stock. If you want to see some jobs and talk to local HO. Give me a call 716-649-5723 We service all of WNY

Wayne_12 · April 2003

btu's

I realize fuel cost vary in different parts of the country. I beg to differ on fuel usage choice when the price is compared on a per gallon cost only. What your are purchasing is btus to heat the building. A house takes so many btus to heat in a heating season. This factor tends to stay the same year in year out.

As a consumer of fuel we need to make a decision on the type of fuel appliance purchsed, based on current fixed costs as well as future expected costs. Odors, maintence, reliability and safety are all factors that enter into the equation. These values are different for each consumer.

The more important issue is what the costomer is comfortable with. The customer has to live with the choice. If they are not satisfied, nobody is happy.

Tom Meyer · April 2003

Propane

I thought Propane had MORE BTU's than natural gas.

Definitely look for Energy Star, but remember the cost of operating your heat source is the SYSTEM EFFICIENCY. Eliminating the house heat loss, etc, as constants, the things which could affect system efficiency would be heat source efficiency, control strategy, thermal breaks, looping strategy (length and serpentine pattern) and fuel type.

Good luck.

Senior Designer/Trainer
Precision Hydronics Corporation
www.precisionhydronics.com

Steve Eayrs · April 2003

I agree that control stratagy...

and the other factors mentioned make a difference, but I would haev to agree the biggest factor is the type of fuel, that is the best deal in your area.
Around here propane will end up costing you about 50% more dollars, if you are comparing an average oil system with an average propane system, BUT I believe it most likely closer to 30-40% more if you use something like the Vitodens. Closes the gap some.
If your talking strickly BTU's, oil will produce aprox. 30% more per gal. than LP, but not sure how NG compares in this? Sure someone out there has more exact figures, off the top of their heads.
Steve

Wayne_12 · April 2003

heat content

Propane 91,500 btu's / gallon
Natural gas 100,000 btu's / therm
oil 138,500 or more commonly refered to 140,000 btu's / gallon

Dave_13 · April 2003

Oil Boilers?

Haven't looked into oil boilers at all. What are some good brands and are they as maintenance free as gas boilers?

BillW@honeywell · April 2003

possible sources for info

Buderus, Burnham, Crown, Peerless, Slant/Fin, Utica, Viessman, WeilMcClain all make oil-fired models. There probably are others, I just can't remember them all! Be sure to check out their websites. Also, visit www.oiltechtalk.com, another site that is dedicated to oil heat.

Jeffrey Eichenwald · April 2003

Efficiency

Dave,

The real question is what type of heating system do you have. If you have electric resistance units, then any hydronic system will require a large investment in new piping and radiation. If you have an electric coil in an HVAC system then you would be looking at a boiler and heating coil in the ductwork. The basic issue is-what does your current fuel(electricity) cost versus any fuel you want to switch to. If you are getting your electricity from Niagra-Mohawk then your electic costs may not justify switching.

Unknown · April 2003

More BTUs per cubic foot

that's true enough. Propane is sold by the gallon, though. Natural gas isn't.

Oil has 140,000 BTUs per gallon (give or take)

Natural gas is 100,000 BTUs to the therm

Propane is 92,000 BTUs per gallon (give or take)

Noel

(NOW I see the other post... sorry for duplicating)

Richard Miller_2 · April 2003

bump for a good thread

I need to get up to speed on oil heat

Jed_2 · April 2003

O.K. so

How many gallons/therm to accurately compare NG to LP?

Jed

steve_29 · April 2003

1 cubic foot natural gas = 1,000 btu +/-

1 cubic foot propane= 2,500 btu +/-

1 cubic foot butane = 3,200 btu +/-

Hope this helps.

Steve Ebels · May 2003

Tom

You're partly right. LP contains about 2300 to 2500 btu's per cubic ft of gas.It's much denser than natural. Natural contains from 960 to 1000 per cu ft. Thats why lp orifices are smaller than natural orifices. The pressure difference is due to the fact that simple physics demand higher pressure to move a denser material through a pipe.

Using the numbers above and my local pricing for LP and natural, this is how it works out.

1 Gl of LP = $1.40. For this 1.40 you get 90,000 btu's or (90,000 divided by 2500) = 36 cu ft of gas for 1.40

1 therm of natural in these parts = $0.52
1 therm of natural gas (100 cu ft)= 100,000 btu so the cost is roughly 3 times higher for LP in my area.

Use these number to extrapolate further if you wish.

leo g_41 · May 2003

bravo!

> Dave, you really have to crunch a lot of numbers

> to do the analysis.

>

> You have to estimate your

> delivered fuel costs, both short term and long

> term and who knows how fast things are going to

> go up. Then you need to factor in overall

> efficiencies of different solutions and include

> your DHW since it is likely around 15-25% of the

> total amount.

>

> You also need to have an idea

> of how much it costs to heat your home. This is

> difficult since your heat is part of all of your

> electrical consumption. If you don't air

> condition then you could compare winter to summer

> bills. From this you can ballpark your electrical

> consumption. Estimate the annual KWH and then

> multiply it by 3400 and you have the net BTUs

> that you are going to have to create from NG or

> oil. A manual J will help you size your system,

> but this will help you calculate your savings.

> This assumes that your electric heat is near 100%

> efficient and that you are going to keep your

> house at roughly the same temps (otherwise factor

> for it). Do this for the water heater as well but

> use 90% or 80% if it is an older water

> heater.

>

> Now comes the fun part. Take your

> proposed solution and break it down by boiler,

> DHW, oil tank or gas lines, distribution and

> rads, pumps and expansion tanks, flue and vent,

> controls. Take the estimates including

> installation "and artwork" and put it into these

> categories. Next put in estimates as to how long

> these various categories should last. Piping 50

> years, DHW 20 years etc. Get whoever is quoting

> to help you on this.

>

> Now take the overall

> estimated efficiency (is AFUE the best guess? I

> dunno but what else is there to go on) and divide

> the annual BTUs by this efficiency number. This

> is how much fuel you'll need. I'd use 90% of the

> boiler efficiency to estimate for a DHW solution.

> Add this together and include any annual cleaning

> costs, the $10/month charge for NG... anything

> like that. Also, estimate any costs you'd need

> for your current heating system if you kept it

> and the life left of it. It should last quite

> some time.

>

> Still with me? Take your current

> annual electrical consumption for heat and water

> and multiply it by your best estimate of what

> electricity will average in cost over the next 5

> years or so. Add to it the annualized cost of

> what you need to fix it. Now compare this to the

> BTU load divided by efficiency (to make it the

> number higher) divide that by 10,000 to convert

> it to gallons and multiply it by the fuel price.

> About 1000 to get it to cubic feet for NG. Add to

> those costs each category of installed cost

> divided by the estimated life for of each

> category. If the proposed solution is more

> expensive per year, there really is no payback.

> This is your best calculation. Compare the annual

> costs of all the solutions and keep in mind the

> quality of your contractor and the equipment.

> For the actual payback calculation, take the

> investment costs (less anything you would have

> had to spend on your current system) and divide

> it by the old fuel cost less the estimated new

> fuel cost. One caveat is that this does not

> factor in the life of the parts and nothing

> lasts for ever except old inefficient cast iron

> dinosaurs. Want mine?

>

> Note these formulas do

> not take into consideration things like comfort,

> quality of service, greenhouse gas reduction,

> snob appeal etc. but it does let you know if it

> is a good economic decision for you.

>

> To

> further complicate this, the building envelope

> must be considered as part of the system as well.

> It isn't very likely that a high efficiency

> Viessmann will rank very high in this but the

> entry-level models should. The Trinity may score

> well but how long would you estimate its useful

> life at versus a Buderus or Smith?

>

> Have you

> currently got a need for NG for anything else or

> a place to put an oil tank?

leo g_41 · May 2003

bravo!

this one is going to the archives! though i didn't quite figure the math out, it sure as hell makes sense!!!

leo g

Tony_8 · May 2003

therms & costs

I am in WNY and the cost of LP & oil /gal. usually hang pretty tight. That's Lp and #2 OIL. Mixed or lighter oil for outdoor tanks during the dead of winter costs more and has LESS BTU value.
In regards to therms, a therm is 100,000 BTU's. That's 100 cu. ft. of NG, 1.09 gal. of Lp, or .71 gal. of #2 FO.
The toss up comes in the maintenance, noise level, smell, etc.
I'd take the oil.
Teledyne Laars MAX & D-MAX have worked well for me. Low mass and good warranty.

joel_14 · May 2003

here

oil is about 1.25 a gallon
propane is 1.85 agallon
natural gas is .90 a therm with all charges added in.
the gas company says it's much lower per therm which is true for the FUEL, but then there is the delivery charge the pipe line charge, the billing charge, etc,etc, etc.

Matt Connolly · May 2003

Why not go with a condensing oil boiler and

get the best of all worlds? The Monitor FCX is the only 95% efficient oil boiler in the US. That way you'll get 95% of the 138,000 BTU the oil has instead of 80%. If you go with condensing and propane and get 95%, that's still less at the same ratio.

Also, the FCX is direct vent so there is no chimney needed. It's been around for 16 years overseas and 3 in the US. go to www.mzboiler.com and check it out. Contact me directly if you have any questions. I've installed 5 so far and serviced / tuned another 15 installed by others. I have an installation CD that you can get for free showing the process from beginning to end. The MZ is on the same CD, for that matter plus a TV show about radiant heat and the MZ in a few homes, including a Frank Lloyd Wright house in NJ.

Good Luck!

Matt Connolly 610-758-9005

Tony_8 · May 2003

D-MAX

is direct vent version of MAX. 86 % eff. Didn't know about condensing oil boiler. Will have to ck out their site.
Thanks! I love the good stuff, it leaves me with less competition and happier customers.

Efficiency???

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