We have a Carrier heat pump but it is electric. In our area, natural gas is not available and the climate is not too severe in the winter, with just a few days of freezing weather. So the electric heat pump is most efficient for around here.

It does work very well, we like it fine. I don't know about the bills because we live in a "green-built" house that is already pretty good for saving energy. In our last house, we replaced a heat pump that had worked well for 20 years before it suddenly stopped one day. The replacement (a Trane) had a much higher energy rating, so that's one good reason for getting a new one.

Woodlander,

Can you tell me more about your green-built home? How old is it? Did you build it? Where do you live?

I have been looking on the LEED website but I can't find any info on gree homes in the Pittsburgh area.

We had to replace our 20 plus year old electric central system about 4 years ago.

We now have a heat pump, can't tell that there is a difference when we do need the heat pump for heating (seldom, we're in Florida).

We were shocked at the difference in our electric bill the first summer. The new one is so much more efficient.

Robyn, about our house: It's about 7 years old and we've lived here since last summer. It was designed by a local architect and won four stars, the highest that was available back then in the Austin, Texas green building program. Nowadays you can get five. :-) If we had built the house ourselves, I would hesitate to brag about it, but we didn't so I think it's okay and hope you don't mind. We're really happy with it.

Here's a list of some of the green features of our house shown on the architect's website:

- Materials
Recycled flooring.
Recycling center.
Engineered floor trusses.
Faswall wall system.
Stucco exterior.
40 yr. metal roofing.
All flooring is durable.
Trim is finger-jointed
- Energy
Designed by design team.
Site-specific design.
Operable thermal chimney.
Raised-heel truss
Large covered porch and arbor.
Low-E Glass
Home designed for 650 sq. ft. of living space per ton of cooling.
Cooling system sized by Manual J based on actual design specification and orientation.
Duct installation to City of Austin Energy Code.
14.0 SEER A/C system.
Ceiling fans in all major rooms. [every room except the bathrooms]
Programmable thermostats.
Roof radiant barrier.
Continuous soffit and ridge vent.
Double pane windows.
Light color for exterior.
No skylights.
Entire system designed and tested by Home Performance specialist.
Sealed recessed cans.
Compact fluorescent fixtures.

The walls are a foot thick, so it takes a long time for the inside temperature to change. It stays 70 or 72 degrees most of the time. The floors are stained concrete downstairs and recycled oak hardwood in the bedrooms. All the interior trim is recycled old longleaf pine. The house is situated on the lot to catch prevailing breezes and minimize afternoon sun penetration in the summer. It's bright inside because we have many large windows, but little direct sun. Low-VOC paints, unfinished all-wood kitchen cabinets, and some other things I don't remember right now. One of my favorites is that a dehumidifier and an air purifier are built into the HVAC system and really keep the indoor air fresh all the time. That's something we've never had before and probably wouldn't have had done on our own, but it's one of the best features. Austin is one of the allergy capitals, but I haven't been allergic since we've been here. Keeping the humidity down means we don't need to use the AC nearly as much in the summer as we used to. Air conditioning is the major energy hog around here. Everyone else I know has turned on the AC already, but we haven't needed to yet. The yard is almost all native plants with no turf lawn, and we're about to start collecting rainwater for the garden.

Green building is a big deal around here. Real estate agents are getting certified as Eco-Realtors and architects are paying a lot of attention to green features in residential and commercial property. Most of the new shopping centers have the big rainwater collection tanks. The City of Austin sells rainwater collection barrels at a cut rate and offers utility rebates for low water use toilets and some energy star appliances. Oh well, this isn't what you asked about, is it?

We've had the usual temperature extremes for this area in the past year -- several winter days in the 'teens and up in the 100s last summer. The heat pump/AC took care of things well without needing to run all the time. If a heat pump is appropriate for where you live, you'll probably like it just fine. Any replacement unit that you end up with surely will be more efficient than your old one. Many improvements have been made in the last 20 years!

robynapa,

check out this site;

Here is a link that might be useful: green building alliance, western pa

We had a heat pump in a house we rented when we first moved to VA and couldn't stand it. It just was not able to keep the house warm in winter. I think if you live in zone 9 or 10 it'd be fine, but if your winters are cold, a heat pump may not be the wisest choice.

We didn't do a heat pump when we replaced our heating and cooling. Instead, we went with a high efficiency AC and gas heater with a whole house air filtration system. The thing that made the biggest difference for us was changing out the duct work and putting in zoned heating/cooling with an upstairs and a downstairs thermostat. That made a huge difference in the gas and electric bills since we were able to run the AC and a higher temp downstairs, where it was naturally cooler and vice versa for the heat during the winter. Before you make a decision looking into zoned duct work.

We have dual zoned heat pumps, 1 up & 1 down. We recently replaced both of them (previous ones were about 20 yrs old). Can't say that I notice a difference in our electric bills to be honest. Our house is 100yrs. old w/ the original windows & there are lots of leaks. I often think that the pumps are still cycling on and off too much but I will chalk that up to the age and leakiness of the house.

Everything in our house is electric & our monthly winter electric bill to run EVERYTHING is the same as what my neighbors go through monthly for oil alone.

It was once suggested to us to convert the downstairs back to oil heat & have the pump for upstairs under the theory that heat rises & then oil prices skyrocketed & we are happy that we replaced both pumps.

I like things really warm so I really need a fireplace to curl up to. I've never had anything except heat pumps or lived in rentals where heat was paid for so I can't compare cost.

I live in zone 6B outside of Philly.

I think you need to look at the amount of heating days you have and what the average temperature is for that and then compare the cost of heating it electric vs. whatever fuel you use for the heater. A heat pump isn't used alone as you do need back-up heat or "emergency heat" as it says on the thermostat. This is your regular furnace that would take over when it gets too cold outside for the heat-pump to work effectively to heat the house. I had mine set right around 35 degrees as the heat pump had a hard time keeping up in the low thirties outside. My house was in Austin like Woodlanders, but built in the late 70's.

A heat pump works by removing heat from the outside air and then using this to heat the house.

If you are planning to sell I'd get a new AC no matter what and then the cost to you will have to determine whether a heat pump makes sense.

The Emergency Back-Up heat on our pump is electric heat.

Woodlander,

Thanks for the info on your house! I would love to see a picture.

Decorpas, Thanks for the link. I have visited that site before. Apparently Pittsburgh has a lot of green buildings but they are mostly commercial. Residential has not yet gone too green yet.

I agree that no matter what we should replace our 25 year old AC. I imagine that any buyer would be put-off by such an old AC.

The sales guy from the HVAC company is coming next week to discuss our options.

Thanks to everyone for the input.

I can't believe you folks are saying your heat pump can't keep up with temps in the low thirties. We had a house we built in the '90's with Trane heat and cooling system, high energy effeciency features, and Van-aire ventilation system that allowed for constant fresh outside air exchange. In zone 5 our heat pump kept the home very, very comfortable down to sub zero temps. If we had any back-ups it would have been electric and I didn't know about it. Our energy bills were phenomenal for the size home we had.

No, our electric heat pump works fine in lower temperatures. It just switches over to "emergency heat." I'm not sure what that means exactly as it seems to work about the same.

As lyfia mentioned, a heat pump struggles once the temps drop below 40 degrees. DS has one on his home with an electric forced-air furnace as back up heat once the temps drop below 40.

sunnytop.....my guess is you had some type of backup heat, especially since you had 'phenomenal energy bills'!

robyn, it appears you're wanting the heatpump just for AC, and if that's the case, then my response is yes, they work well.

I suggest talking with more than one HVAC representative........both for opinions and prices.

I didn't even know that my heat pump had an an 'emergency back-up' until the heating company told me. It's standard. A heat pump automatically switches over at a designated temp.

When my upstairs heat pump gave out I was able to run it on the emergency back-up & essentially heat my home just off electric heat & not drawing the air in from outside.

Comfortable is also a matter of opinion. Most people think our home is too cold. At night it is set to 58 & during the day 65. 70 is sweltering to us & most people I know keep it at 72. We always turn the heat up when we have company so that they feel comfortable.

Can't wait for my FP someday though!

I think most heat pumps go to "resistant heat" i.e. straight electric heat when it gets to cold for them to keep up. How much extra that costs depends on how expensive electric is in your area. Someplaces electric is fairly cheap. Others its the most expensive for that region. A house I just looked at had put in a heat pump with a propane (country house) backup because the resistant electric was considered expensive. Until propane skyrocketed of course.
Really it depends on your region. Ask your HVAC why he recommended it.

sunnytop as others mentioned you probably never noticed that it switched from heat pump to back-up heat and in an all electric house that would be resistance heating elements which is very costly compared to other types of furnaces as it uses a lot of energy. A heat pump can be combined with other sources of heat that kicks in when the heatpump sends a signal saying to switch to emergency heat. It is all seamless and won't be noticed to the homeowner other than if you go outside the compressor won't be running when the heat is on as it would when the heat pump is heating the house.

In our new house we have a propane furnace that works as the back-up heat when outside gets too cool, however we aren't using it as a heat pump since propane is cheaper to use than electric where we are.

The HVAC guy said that when the temp falls below 30 our natural gas furnace would kick on. The gas co. also will reduce your rate if you install a heat pump. He also said that the heat pump would be used approximately 200 days per year. I guess the other 160 days you use either the gas furnace (when temps drop below 30) or nothing.

Days like today when the temp is 69 we don't use heat or air so the system is off.

If you are in Pennsylvania, think about how many days a year the temp goes below 30. Why would you want to rely on an alternate heat system kicking in when you can have one consistent system?
Heat pumps are terrible ideas, IMHO. They just can't keep up. I live in Va., and there are still homes/townhouses I've seen with heat pumps. Va has mild weather, but winters can get very cold (and have gotten colder the past several years). And I'll tell you, to most people, "heat pumps" on a home sale spec sheets is not a selling point--even if it is a Trane--they are installed as cheaper options; I have never seen anything claiming they were better utility wise or environmental wise (and I just replaced my non-heat pump heater with a regular Trane heater, so it's not like I'm being cheap!).

It'd be worth your time and money to get another heating company rep in for an opinion and estimate.