Gas and Oil Home Heating Furnaces - gas furnace with add-on AC or heat pump?

I need some advice!

I live in Olympia, WA (average temp in winter is 32-46 degrees Farenheit) and my home is about a year and a half old and I currently use a Gas Furnace for heating (natural gas). I want to add central air conditioning to that for summers. I am trying to decide which would be a better investment though… a heat pump or an add-on air conditioner. I know that if I go with the heat pump, then my gas furnace will serve as a backup during the cold days of winter, but will the initial investment in a heat pump be worth the savings on my energy bill in the long run?

I tried the fuel calculator on www.warmair.net but I simply don't know how to fill out the information. Puget Sound energy publishes gas rates based on therms, whatever that means. I can't figure out how to convert and plug in the correct numbers. :wall:

My home is a 1-story, 1340 sq ft. My total electric and gas bill combined in 2004 was about $930. Gas was a large portion of that but I don't have the exact figure.

I’ve already had 4 contractors come to my home to give me estimates on air conditioners and/or heat pumps and I am getting drastically different suggestions and prices from each of them, which means I am more confused than ever. :confused:

At this point I am debating whether to go cheap or go big. If I don't go with a heat pump, I will just get the Trane 11.5-Seer 2 ton R-22 Air Conditioner (XR11), from a local Trane contractor. The quote on that installation is about $2700. Or I could scrap that and go for a heat pump, in which case I would go with the Trane 14-Seer 2 ton split system R-410A Heat Pump (XL14i). Estimate on that is $4544 (plus a $300 Trane rebate if I act soon).

I'm all researched out so I could really just go for some practical advice at this point.

thanks,
Monica

You have to find out the cost for gas or electric there to say heat pump or not. What ever go for a seer of 14 or better for AC or heat pump. Trane has units higher that are still R 22. I for sure would stay with R 22 its still made till 2030 and dont cost near as much as the R410a does.Now if you are going to be in the home for 10 years go for the good stuff.If not go cheaper Train has a XL19i thats R22.

ED ;)

I like the dual fuel set-up....heat pump with gas furnace back-up. I prefer a matched system if at all possible-same manufacturer of furnace and heat pump or AC. But before I give advice, please advise the following.

1. Model and Manufacturer of gas furnace
2. Age of gas furnace
3. advise your gas cost/therm and electric cost/kwhr.

I will help you make the energy calculation.....

:thinker:

1. Gas Furnace is a Carrier - Model 58STA/STX
2. 1.5 years old - (I live in a track home neighborhood.... we all have the same builders and HVAC contractors etc).
3. Electricity Rates: (http://www.pse.com/account/pdfs/elec_summary_prices_2005_04_01.pdf)
First 600 kWh: .051687 cents per kWh
Remaining over 600 kWh: .06872 cents per kWh

Gas Rates:
(http://www.pse.com/account/pdfs/gas_summary_prices_2005_04_01.pdf)
.986550 per Therm

I thought about going with the same contractor that put in the furnace system but they are more expensive than this Trane contractor I talked to. I also looked them up on the Better Business Bureau website and they had at least 3 complaints against them (although resolved). The Trane contractor has 0 complaints.

It appears you are in an ideal location for a heat pump add-on, particularly with the idea that you want AC, why not pay a little more and get a high efficient heat pump that will also save you $$$ over your gas heating costs. Your electric rates seem very reasonable and over the next few years should be more stable than gas. As mentioned, I like the idea of a matched system and since you have a Carrier gas furnace that is still being manufactured, I would recommmend investigating a high efficient Carrier heat pump(or Bryant-Carrier's sister company). Your gas furnace is rated at 80% AFUE which will make a HE heat pump very attractive.

58STA/STX Profile(info provided by Dring AC website)
Life always throws you a couple of curve balls, so it's comforting to know that Carrier continues to offer affordable products with rock-solid reliability like the 58STA/58STX. When winter arrives with its cold and snow, your furnace is the last thing you need to worry about. That's why so many homeowners trust Carrier with their indoor comfort needs. Carrier offers 100 years of indoor comfort innovation, and we put that expertise to work in every product we create, including the 58STA/58STX gas furnace. This furnace is the evolution of one of our most reliable and popular 80% AFUE (Annual Fuel Utilization Efficiency) gas furnaces. We took an excellent design and made it better, adding extra-quiet performance and a more compact, versatile cabinet that helps make the 58STA/58STX an excellent fit for your comfort.

1.Insist on a written manual J heat/cool load calculation for properly sizing your equipment. I would suspect you would require a 2 to 2 1/2 ton unit but the Manual J is the professional method of sizing equipment.

2.For a heat pump add-on, you will require an outside thermostat that connects to gas furnace that you can adjust up or down to set the temperature where heat pump will switch over to gas. Usually this is set at/around economic balance point around 30 to 35 Deg Fah. You want the heat pump to do the major heating work and only use the gas backup on very cold days.

3. You will need a matched evaporator coil rated correctly by size and SEER of your heat pump and properly fitted to your gas furnace.

4.I suggest a heat pump with a minimum of 13-14 SEER and an HSPF of 9+.

5.Make certain your dealer verifies the size of your gas blower and that your existing ductwork is capable of handling the heat pump add-on.

6.I would look into a good media filter cabinet like Honeywell,AirBear,AprilAir.

7.Puron(R-410a) refrigerant heat pumps are OK but do not pay more. R-22 refrigerant equipment is fine.

8.Have your installing dealer check your thermostat and make certain it is compatible with your equipment add-on whether AC or heat pump.

9.Make certain the dealer you select has experience with these heat pump add-ons.

I would expect you to save at least minimum of 25% over your current heating costs. I do like Trane equipment but in your case I prefer a matched system of same manufacturer so I would suggest contacting a Carrier or Bryant dealer. I have a dual fuel system-heat pump with gas furnace and I love it. It saves $$$.

Good luck!

At that electric rate Id for sure take out the gas and go full heat pump for sure Check out the Trane XL16i You can get a SEER of 17 and a HSPF of 10.55 on the heat pump side.

ED :thinker:

Ed makes a valid point and good suggestion. However, I think it depends on what a written manual J tells you as far as sizing equipment. The Trane XL16i heat pump only comes in 2,3,4,5 ton sizes-no 1/2 ton increment. With the appropriate size variable speed air handler, you would get a premium system along with a 10 yr limited warranty on parts for a complete matched system that is very efficient, quieter,very reliable,cleaner air, very effective dehumidification-don't know if that's an issue in your location. I think it depends on what you are looking for, your budget, and what size equipment is determined by the Manual J load calculation. Personally, I like the idea of the dual fuel but take a look at it from a cost standpoint.

I can only find two Carrier contractors in my area. One is Sears and the other is the same company (Sunset Air) that installed all the gas furnaces in all the homes in my subdivision.

Sears is out of the question because their salesman was a complete jerk.

Sunset Air wants $2955 for the Comfort 10 R/22 10-Seer 2-ton A/C unit but they are PUSHING HARD for customers to go for the higher seer models with PURON. They even gave me a little brochures that talks about a new law that requires 13-Seer or higher starting in 2006.

They want $4045 for the Performance Series Carrier A/C 38TSA024 2-ton 14-Seer PURON. This seems awfully high priced considering I can get the Trane 14-Seer Heat Pump for a couple hundred more (with a 10yr warranty on parts instead of 5yr on the Carrier).

And finally... they want $4566 for the 2-ton 14-Seer Carrier Heat Pump. Again, that' smore than the Trane but with less warranty.

Sunset Air told me they do not need to do a manual J heat load calculation because they know these track homes inside and out since they've installed all the furnaces etc for all the homes in this area. (There are only 4 or 5 different styles of homes in this subdivision so indeed they have probably installed these units in the exact same home as mine before).

Don't know what to think of Sunset Air at this point. It'd be easier to go with them since they installed the furance but I feel skeptical of their prices and sales tactics... and like I said they did have 3 complaints noted on the BBB site.

-Monica

First of all, do not purchase HVAC equipment from Sears or Home Depot.

Now to your particular dilemma.

I still like the idea of pairing a high efficient heat pump with your 1 ½ yr old Carrier gas furnace. Regardless of what your dealer says, I would insist on a written Manual J heat/cool load calculation for properly sizing equipment. This gives both the homeowner and dealer protection if a problem over equipment sizing occurs. Your location is ideal for a heat pump add-on. While a 2 ton unit seems borderline undersized, I have checked average winter and summer temps and because of your moderate climate, I believe a 2 ton to be adequate. Because you are looking for operational savings, I would only purchase a heat pump with a minimum 14 SEER and 9+ HSPF . Anything less defeats the purpose for savings. I would look at the Carrier Comfort 14 heat pump.

Now for comparison purposes, replacing your gas furnace with a high efficient Trane XL14i heat pump with appropriate air handler also seems recommended.

On the surface, your quotes from the Carrier dealer seem high and the Trane quote more reasonable particularly when you get the 10 yr limited parts warranty on a matched system. I know the Trane XL14i heat pump is reliable equipment. It comes in both R-22 and R-410a refrigerant. I would not pay extra for the R410a and if that is the case would suggest the model with the R-22 refrigerant.

Hope this helpful. Good Luck!

Should I avoid the 14-Seer Carrier Heat Pump if it only has an HSPF of 8 point something? I don't have the specs in front of me but it was under 9.

The Trane XL14i had an HSPF over 9. What do you mean about replacing the gas furnace with the heat pump though? Wouldn't the furnace remain as a backup when it gets below a certain temp outside?

The Trane contractor did tell me that he would have to replace the air handler if I get the heat pump.

thanks for all your help by the way!

I do this for a living .what I did I put in a trane 2 stage gas , varible heater a trane 14i heatpump outside & robert shaw t-stat.If you use the robert shaw stat you do not need to use a fossil fouel kit.It's built inside the stat..and you can contol humidy& it also can dehumidfy as well.It will also give a out door temp.That is good for your heat pump so you can set your hi & low ballance point .you also can set you 1st stage & 2nd stage heat .I have propain so I had to put in a heat pump with gas back up Tne way pro pain prices are