Oil to propane worth it?

[beenthere]

You can have the heat pump run to 12 to 18'F range with a 5 kW or 3 kW heat strip.
Your locale seems to experience a huge amount of hours at less than 20'F.

http://www.wunderground.com/history/...q_statename=NA
I can see a heat pump running nearly continuous for ~1,600 hours / 10 weeks ( when < 34'F)

ATTACHMENT: Balance Point with 2.5 and 3 ton Heat Pumps.

I have not performed Heat Loss calc.
Heat Loss in graph is based on stated use of 2.5-ton heat pump to 30'F.

Based on a lengthy review of temperature data and setting up an approximate temperature bin,
I anticipate Oil use should be reduced to ~150 gallons if you set a switchover to about 16'F.

You need a tech quite conversant in Controls to set-up both an electric strip and
oil furnace as AN AUX Heat/ Heat Pump operation + really a DUAL FUEL SYSTEM.

Running the heat pump and a 5 KW aux heater at $0.10 per KWH, will probably cost more then using his oil heat at $4.00 a gallon(based on 80% efficiency)when the outdoor temps are below 20.

Need to plot a economical balance point graph.

[Brutismax]

How about getting the 95% 2 stage variable speed propane furnace and having the heat strip installed at the same time. The oil furnace is atleast 15 years old. The variable speed blower seems like it would help with savings and comfort. Want to have a plan before I get estimates and can ask about the 3 stage deal when I call. Something needs done $1600+ for heat sucks.

[beenthere]

I wouldn't bother with adding any aux strip heat. Just dual fuel. You could have a hard enough time finding a company that can set up a dual fuel right.

[dan sw fl]

Running the heat pump and a 5 KW aux heater at $0.10 per KWH, will probably cost more then using his oil heat at $4.00 a gallon(based on 80% efficiency)when the outdoor temps are below 20.

Need to plot a economical balance point graph.

$4.00 ………….. per gallon
139000 ………….. BTU/ gal
0.80 ………….. efficiency
111200 ………….. New BTU
1.112 ………….. Therm /Gal
$3.60 ………….. per therm Oil
…………..
$0.100 ………….. per kw
100000 ………….. BTU/ Therm
3412 ………….. BTU/ KW
29.308 ………….. kW/ therm
$2.93 ………….. per therm Straight Electric
2.50 ………….. COP at 17'F
$1.17 ………….. per therm Heat Pump
307% ………….. Oil = 3.1 X Heat Pump at $0.10 /kW
…………..
$0.067 ………….. per kw
$1.96 ………….. per therm Straight Electric
183.5% ………….. Oil = 1.8 X straight electric at $0.067/kw
.............................
$2.17 ………….. per gallon LP
95000 ………….. BTU/ gal
0.80 ………….. efficiency
76000 ………….. New BTU
0.76 ………….. Therm /Gal
$2.86 ………….. per therm LP
97.4% ………….. LP = 1.0 X straight electric at $0.10 / kW
_____ ________ LP = 1.46 x Straight Electric at $0.067 /kW
243.6% ………….. LP = 2.4 X Heat Pump

[beenthere]

When the heat pump and 5 KW of strip are running 24/7 they will cost more then the oil which will shut off and have times of no oil consumption. Plus the heat pumps defrost periods

[meplumber]

Dan. We just went through this argument with some kid over in one of the other forums. Electric heat doesn't work in cold climates. Period. Exclamation Point. I don't care what your numbers tell you. I made too many conversions from electric back to oil in the late 80's after the oil embargo drove people to electric. It cost them a fortune and they were never comfortable. You can't give electric heat away up here.

LP/Heat Pump dual fuel will give you a great combination of comfort and affordability. Even oil is more efficient than electric in cold climates. As beenthere just said, the electric is never satisfied, it has to run almost constantly. The oil will make temp and shut off for periods of time.

[dan sw fl]

How about getting the 95% 2 stage variable speed propane furnace and having the heat strip installed at the same time. The oil furnace is atleast 15 years old. The variable speed blower seems like it would help with savings and comfort. Want to have a plan before I get estimates and can ask about the 3 stage deal when I call. Something needs done $1600+ for heat sucks.

I'd go all electric with latest Heat Pump WHEN the furnace dies. +++ WHY would one buy a High efficiency LP if use is going to be minimal.?

[Brutismax]

I will let you guys know what the local contractors recomend, in the next week or two. Again Thank you for the help.

[dan sw fl]

I will let you guys know what the local contractors recomend, in the next week or two. Again Thank you for the help.

I guess one could ' put themselves at Their Mercy'.

[Brutismax]

http://www.aireflo-hvac.com/products...HP13_49612.pdf
I can adjust Thermal Balance Point Chart to this Aire-Flo information.

Have you ever had the switchover point set to less than 30'F?

To perform an accurate economic analysis I would need temperature bin data for your locale.
It's a bit of an effort to derive this data from the Weather Channel information on daily high/lows.
What is a 'major' city that is close ( 40 miles or so)?

I set the switchover to 25, last night it got that cold,tstat is set to 71, this morning it said inside temp 69. So 30 is lowest the 2.5 ton will keep up with.

[beenthere]

If you had an IAQ stat. I'd set the heat pump lock out to 25 and teh furnace lock out to 30, and use balance point plus 2° droop. To allow the heat pump to run during the day when its 25 outside, but have the furnace take over when it lost 2 degrees at night time.

[Brutismax]

If you had an IAQ stat. I'd set the heat pump lock out to 25 and teh furnace lock out to 30, and use balance point plus 2° droop. To allow the heat pump to run during the day when its 25 outside, but have the furnace take over when it lost 2 degrees at night time.

Can the HW 8320 be set to do that? If not I am going to leave it set to 25 for now, if we lose a couple degrees at night we can live with it, should be warming up soon. Want to avoid burning anymore oil at $4 a gallon

[Brutismax]

Alternative -
1. Check infiltration to assure < 0.5 Air Change per Hour
2. Check and upgrade ducts to 1,050 CFM capability
3. Install new high end 3-ton heat pump - thermal balance point would be ~23'F

3-ton heat pump with 3 kW heat strip, the House- Heat pump total electric SYSTEM would be adequate down to 15'F.
Oil use at temperatures < 15'F ought to be < 100 gallons.



Propane at $2.17 / gallon, 90% efficient is $2.54 / 100,000 BTU/Hr ( therm)
Electric at $0.10/ kw-hr down to ~20'F would be $1.25 / therm or half of propane.

What about putting in a 2-stage heat pump large enough to heat down to 15 on it's own and run ac on low stage? Don't want to change out my HP right now, but would something like that work or maybe a dumb idea?

[beenthere]

Carrier Greenspeed might work like that. Its a modulating heat pump. So you could get a 3 ton if your A/C load is only 2 tons, or 4 ton if your A/C load is 3 tons.

[catmanacman]

have you considered a single stage 95% efficient furnace with a high efficent (x13) motor .or a two stage furnace with a varible speed motor then when and if you wanted you could go to a two stage heat pump

[genduct]

#2 @ 80% costs you $35 ? million BTUs, Porpane @ 90% costs you $27 / million BTUs
400 gal;lons are 54 million BTUs with $5 savings $ saves you $270
What would you spend to save $270 ?
Don't know where you live but your heat bill sounds pretty good to me

GAs or propane short cycling is not as bad (inefficient) as oil, short cycling Might be a factor or Hot water or air system, or domestic hot water is ?

[genduct]

Whoops, Faulty Math...That's $7 times 54 or a little less than $400 savings
Gotta stop doing the math on the back of an evelope

Talking about envelopes, any opportunity to improve insulation or better to "tighten up" your home?
Have you done a blower door test to give you an idea of how much infiltration you have now?

[Brutismax]

#2 @ 80% costs you $35 ? million BTUs, Porpane @ 90% costs you $27 / million BTUs
400 gal;lons are 54 million BTUs with $5 savings $ saves you $270
What would you spend to save $270 ?
Don't know where you live but your heat bill sounds pretty good to me

GAs or propane short cycling is not as bad (inefficient) as oil, short cycling Might be a factor or Hot water or air system, or domestic hot water is ?

The calculations I have seen and done look more like $4-$500 in savings between propane and oil. I do understand that the prices will change wich makes the decision harder. I didn't think my heat bill was good at all $1600 for oil plus what electric the hp uses, we don't have a big house. I like the idea of adding a heat strip to help the hp down to 15 like dan sw fl said but then others say the electric heat is never satisfied and not comfortable.

[Brutismax]

Yes I plan to add more insulation in the attic and look at some other things I can do. Being an older home there is prob lots of room for improvement.

[genduct]

Consider that the extra insulation can hit the diminishing return thing but the SEALING PART is the area that really needs to be addressed. THink you should have a blower door test to 'benshmark" your infiltration as the first step