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Discussion Starter #1
I'm replacing a split 2.0 ton compressor & furnace with either a 2.5 ton compressor & furnace OR 2.5 ton heat pump & furnace. My lines will have to be replaced and return duct modified (new box to reduce noise).

The quotes from this company range between 6-9K. I was told $1500 for labor, $1200 for parts, the rest for equipment. Seem high?
 

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Prices are highly localized, so get some other quotes to answer that question. In fact, that is always wise when considering replacing a system.

Also, why are you adding another 1/2 ton of capacity? Did the contractor do a load calc (aka Manual J)? Oversizing a system increases initial cost, increases operational costs, decreases humidity control and impacts longevity.

When you get other quotes demand a load calc.
 

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Discussion Starter #4
He didn't explain a Manual J to me, but he did take measurements of the ductwork and state 1/2 ton larger was the largest he would recommend. Its undersized now, at 2 tons, considering the living space is about 1500s/f. Its a split level house in the HOT, humid southeast.

I was hoping to get a ballpark figure here. I like this company, but was shocked when friends/neighbors had their units replaced for about half that. Most of them were gas packs though, not split units with new lines. Most of them were larger capacity though.

If I went to a heat pump ONLY, with an AUX heat strip, etc, and did not use a furnace what will be required at my breaker box? I'm using two 30A switches for the outside compressor now. The furnace is separate. I can supplement with gas logs, for temps in the teens, which is rare down here.
 

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You may in fact be undersized, but using sq ft as a guide is the old rule-of-thumb inaccurate way.

A Manual J takes into account such things as number and type of windows and doors, insulation values, exterior type, roof type, basement/cellar/slabs, living volume, etc., give the typical temps of your locale and the desired temps the owners want to achieve. Unless your contractor had your blueprints, they really need to take some measurements to do a Manual J properly.

You could discover that a 1/2 ton extra is not enough. Even more likely you could discover the extra capacity you need for cooling and heating is different.

Since you currently have A/C it is unlikely you'd need any breaker box changes.

If you go with a heat pump there is no need to remove your current furnace unless it is on its last leg. Most heat pump only installs include backup heat strips that are probably more expensive to run than even an old inefficient furnace. That's a bit off track, but do keep that in mind.
 

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Discussion Starter #6
Ok, thanks.

The furnace is on its lag leg, so I'm going to do heat strips and/or a new furnace. When I mentioned doing ONLY a heat pump after the quote, he said there might be complications (breaker box, meter?, etc). I like the idea of not having a gas or venting in my house though. The hybrid options, furnace below 30 deg, H/P above 30, were of course more expensive than just A/C + furnace ($7000+).
 

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Your current A/C circuit should suffice for a heat pump, but he may have meant you need another circuit for the heat strips. If your breaker box is not big enough, it will have to be upgraded.
 

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Your current A/C circuit should suffice for a heat pump, but he may have meant you need another circuit for the heat strips. If your breaker box is not big enough, it will have to be upgraded.
Sorry I'm such a newbie, but what might this require for the size I'm doing, 2.5T? 240 or 120? Amperage?
 

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Sorry I'm such a newbie, but what might this require for the size I'm doing, 2.5T? 240 or 120? Amperage?
Heat Strips start at 5KW and get bigger and are all 240V. You will likely need more than one depending on how much heat you need. So adding the heat strips together, the total KW you can figure the amps and size the circuit accordingly.

You can also figure how much your aux will cost you vice a furnace backup, and figure whether a furnace is a more longer term cost effective option.
 

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Price is in the ballpark but as a previous poster said, they are very region specific. Get 2 or 3 more quotes as they can range 2 fold! Get recommendations for installers from your neighbors
 

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Discussion Starter #11
Heat Strips start at 5KW and get bigger and are all 240V. You will likely need more than one depending on how much heat you need. So adding the heat strips together, the total KW you can figure the amps and size the circuit accordingly.
So that's 5000w/240v = 21 amps. What amp breaker would that be?
 

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1 Therm of energy can be had from approx. 29 kwh of elec heat, 8.4 kwh of heat pump heat (COP = 3.5), 4.2 kwh of heat pump heat (COP = 6.9).
2 tons is 24,000 BTU/hr is 5.8 therms each 24 hrs.
I pay 16 cents/kwh.

Regarding undersized, has your present unit been running at full capacity? My oversized gas furnace runs 1/4th of the time during an average, or slightly colder, winter.

Grainger.com can give you some prices for just the equipment. This site
http://www.degreedays.net/
will give you numbers on what kind of climate you have to cancel out.

You have some math to do.
 

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In some areas. The price you got, would be considered a low ball price.
 

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Discussion Starter #14
Regarding undersized, has your present unit been running at full capacity? My oversized gas furnace runs 1/4th of the time during an average, or slightly colder, winter.
The AC couldn't maintain 80 on an 85 degree or hotter day, but it did have a slow leak. It basically ran ...until the blower motor (and cap?) cooked itself today... 16-18 hours a day at that temp or higher. Basically it was only off between 1am and 8am. Its not going to kill me being out, but it sucks for now. It's been 95+ for nearly a week.

The furnace could raise the temp from the upper 50's to 70 in less than an hour. I did have problems with it however. Pressure switch, CAB rattling, motor noise/wobbling, and now blower motor/cap. The return duct is 20 in long and in my family room. It is/was extremely LOUD ...one issue that will be addressed. Gas is also expensive, relative to watts here (9-12 cents), which is why I'm considering electric only. I have gas logs for an emergency.

Honestly, I'm just smart enough to know I have a lot to learn (if I choose that route) and I'd be a fool to sink $7K+ blindly. That's why I'm here. I can learn a lot, but it will take a while. I called three people out last spring and no one had time for me. Now I'm looking at window units to get me by while I sort through it all. Yeah, I should have done it sooner, but I barely have the money to do this.
 

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When I took out my old oil furnance and A/C unit and replaced it with a 5 Ton heat pump, I had enough power at the outdoor condenser, but I did not have enough power for the Air Handler and backup heat.

I installed 20kw of electric heat, which required two 60 amp breakers. (240v)

Unfortunately, there was no electrical panel in the basement and not enough power down there already to do this.

I was able to temporarily run the air handler in A/C mode off of the (240v) water heater circuit so that we would at least have cooling through August.

I installed a 100 amp sub-panel in the basement which now feeds the AirHandler, the backup heat and a few other minor circuits.

When my unit is running in the winter and all the heat tape is on, it pulls around 86 amps.

I do now wish I put in a propane or fuel oil aux heat instead of the electric as getting a $500+ electric bill in January was not expected.
 

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A 100 amp sub panel is undersized for a 20 KW strip heat package and any other load.
 

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getting a $500+ electric bill in January was not expected.
1362 HDD for January for Dayton, OH. At 8 cents/kwh average rate in Ohio this is 8.7 kw all the time, 7 therms in 24 hrs.

For a 2000 sq. ft. house including basement it's 350 BTU/day/sq.ft.
1362 HDD/31 days = 43.9 HDD in one day
350/43.9 = 7.8 BTU/sq.ft./HDD, slightly above the average 6 BTU/sq.ft./HDD.
 

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A 100 amp sub panel is undersized for a 20 KW strip heat package and any other load.
It was borderline based on the numbers I ran, but since I couldnt find 125 amp breakers for my #2 copper cable, I used 100 amp.

I also have it wired so that the full 20kw doesnt come on unless it is really needed based on a smart thermostat.

1362 HDD for January for Dayton, OH. At 8 cents/kwh average rate in Ohio this is 8.7 kw all the time, 7 therms in 24 hrs.

For a 2000 sq. ft. house including basement it's 350 BTU/day/sq.ft.
1362 HDD/31 days = 43.9 HDD in one day
350/43.9 = 7.8 BTU/sq.ft./HDD, slightly above the average 6 BTU/sq.ft./HDD.
Dayton Power and light charges 10.5 cents per KW/Hr.

As for the rest of your post, I am not sure I understand it.
 

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Dayton Power and light charges 10.5 cents per KW/Hr.

As for the rest of your post, I am not sure I understand it.
For a $500 elec. bill @10.5 cents/kwh you must have used 4762 kwh during this 31 day period, or 154 kwh per 24 hr day.
Assuming this all went into heating during January '09, which averaged 43.9 Heating Degree Days per day in your location, and assuming your house is 2000 sq. ft., you used 7.8 BTU per sq. ft. per Heating Degree Day, which is slightly more lossy than the "average" residence.

This may explain your surprise at your high heating bill.

Since you have a heat pump this is a pretty high bill, unless it was so cold that the aux. heat ran most of the time. Probably it did.

As to using propane or fuel oil instead, 1 Therm of energy can be had from approx. 0.71 gal of fuel oil, 1.1 gal of propane, 29 kwh of elec heat, 8.4 kwh of heat pump heat (COP = 3.5), 4.2 kwh of heat pump heat (COP = 6.9).
What rates would you be paying for those fuels in your area?
 

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Yoz.

He has around 5,000 sq ft. Including the basement.
 
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