High Eff boiler Calc ? (by NE [PA]) Apr 18, 2019 6:06 PM|
High Eff boiler Calc ? (by Robert,OntarioCanada [ON]) Apr 18, 2019 6:35 PM
High Eff boiler Calc ? (by Steve [MA]) Apr 18, 2019 7:00 PM
High Eff boiler Calc ? (by don [PA]) Apr 18, 2019 10:29 PM
High Eff boiler Calc ? (by David [MI]) Apr 19, 2019 5:12 AM
High Eff boiler Calc ? (by Oregonwoodsmoke [ID]) Apr 19, 2019 6:27 AM
High Eff boiler Calc ? (by Robert J [CA]) Apr 19, 2019 10:42 AM
High Eff boiler Calc ? (by Toddb [MN]) Apr 19, 2019 1:05 PM
High Eff boiler Calc ? (by Robert,OntarioCanada [ON]) Apr 19, 2019 3:50 PM
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High Eff boiler Calc ? (by NE [PA]) Posted on: Apr 18, 2019 6:06 PM
If all things were equal and I had a propane boiler that operated at 85% efficiency and used $6,500 a year to heat a building, how much would I save with a high efficiency boiler that operates at 95% efficiency.
I know there are tons of variables with outside temps and price per gallon, etc.. I'm asking assuming that everything was exactly the same.
I can't figure out the math. --174.201.x.xxx
High Eff boiler Calc ? (by Robert,OntarioCanada [ON]) Posted on: Apr 18, 2019 6:35 PM
High efficiency boilers efficiency drops to 87 per cent once the output temperature reaches reaches 60 degrees Celsius or 140 F as the secondary heat exchanger does not extract heat. If the boiler is used with a indirect hot water tank which uses the high efficiency boiler to heat the immersion then the overall efficiency goes up as a indirect hot water has heat loss of less one degree per hour in standby mode where a direct fired hot water tank will lose 7 to 12 degrees per hour as heat goes up the chimney. Upgrading insulation, windows and air sealing building helps reduce the output temperature of the boiler. Copper finned radiators require a higher temperature where during the coldest months the boiler will not at high efficiency. --147.194.xxx.xx
High Eff boiler Calc ? (by Steve [MA]) Posted on: Apr 18, 2019 7:00 PM
Theoretically a 95% boiler is actually 11.76 % (95-85 = 10, 10/85 = 11.76) more efficient than an 85% boiler.
At best a 95% boiler should use approximately 88.2% of $6,500.00 = $5,735.00 for a savings of $765.00.
In reality, I doubt that you would actually save this much fuel. --96.237.xx.xx
High Eff boiler Calc ? (by don [PA]) Posted on: Apr 18, 2019 10:29 PM
OK, so you buy $6500 worth of fuel, you can look at that as $6500 worth of potential heat. Your furnace, at 85% efficiency, put out unknown H, which is the amount of heat needed to keep your house warm over the Winter.
Now, with the new heater, you will still need the same amount of heat to heat the house over the Winter, so H stays the same. You don't know how much fuel you would have to buy (F).
Combine the two equations and you get $6500(.85)=F(.95)
Solve for F and you get F=(.85/.95)$6500
High Eff boiler Calc ? (by David [MI]) Posted on: Apr 19, 2019 5:12 AM
I would not replace a perfectly working furnace with a high-efficiency one just for the "energy savings." But, when the day comes, and I need to replace the furnace, I would buy a high-efficiency one over a "low" efficiency one.
In addition to the actual energy savings, your utility may offer rebates for the high-efficiency furnace. --50.4.xxx.x
High Eff boiler Calc ? (by Oregonwoodsmoke [ID]) Posted on: Apr 19, 2019 6:27 AM
If you don't actually need to replace the furnace, your dollars will give you a better return if you put them into weatherization instead of upgrading the furnace. --98.146.xxx.xxx
High Eff boiler Calc ? (by Robert J [CA]) Posted on: Apr 19, 2019 10:42 AM
As a plumbing contractor that attends product show's, once I've done all of the numbers -- the savings takes years to recoup the extra cost of the purchase to benefit from the savings. Of course this isn't true when the old furnace is a guzzler and the new one is top of the line latest technology. But in rentals things get abused, broken, stolen or over-used. I wouldn't put a top of the line anything in a rental...unless I was planning to sell in the near future. --47.156.xx.xx
High Eff boiler Calc ? (by Toddb [MN]) Posted on: Apr 19, 2019 1:05 PM
We have had so many issues with our high efficiency boilers. the maintenance costs eat up any savings or at least have for us. --73.94.xxx.x
High Eff boiler Calc ? (by Robert,OntarioCanada [ON]) Posted on: Apr 19, 2019 3:50 PM
Installing a indirect hot water tank will use less energy then a direct fired hot water tank as a indirect hot water tank has a standby heat loss of less then one degree per hour. Direct fired hot water tanks have a open stack where there is heat loss of 7 to 12 degrees per hour as heat goes up the chimney. A Tekmar electronic boiler control system with a warm weather shut down will turn off heat on warmer days and evenings when the temperature is set. Insulating all the heating, hot water pipes in the boiler room will put more heat in the building as there is no point in heating the boiler room. View some videos on You Tube about conserving energy. If a building was super insulated there would no need for a heating system as that is called net zero. Some boilers have a vent damper which closes once the boiler turns off limiting the amount of heat going up the chimney. Having multiple boilers use less energy as the heat demand is variable where on the coldest days or nights require maximum capacity. Cleaning out the dust of copper finned radiators along with installing reflective tape puts more heat in a room at a lower temperature. Look at the building envelop where insulation improvements will reduce energy consumption. --67.71.xxx.xxx
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