The Shocking Truth About Heat Pumps

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heat pump reversing valve

Should you use natural gas heating rather than a heat pump in your home? Some say the interest in heat pumps is fueled by irrational exuberance. Others say that because they require supplemental heat, heat pump performance is not acceptable. Another group says you'll get a better HERS Index by using gas heat.

So how's a person to decide? Some of the folks who say these things are smart, established, and well respected in the HVAC and energy efficiency communities.

Calming the chaos

The first answer to the lead question in this article is yes, it may be better for you to use natural gas heating in your home. The second answer is no, you might be better off with an electric heat pump. You also can reverse the order. In other words, the best answer is, it depends.

The truth is that anyone who says never or always is usually wrong, especially when it comes to which products, materials, or technologies to use in your home. In the case of gas heating versus heat pumps, here are some of the issues you need to consider:

  • Climate zone
  • Electricity vs. gas rates and service charges
  • Where your electricity comes from
  • Building enclosure
  • Modern equipment

Climate zone

gas furnace vs. electric heat pumpIt doesn't make a lot of sense to put in a gas furnace in Valdosta, Georgia or Phoenix, Arizona. Where cooling loads dominate, heat pumps do, too.  

The further north you go, the more gas heat you find. That's changing, though, because building enclosures are getting better (more airtight and better insulated) and because we have better heat pumps.

Climate zone does matter, but the one-size-fits-all approach is becoming obsolete, even when applied to specific climate zones. I've seen heat pumps in Maine and furnaces in Florida.

Electricity vs. gas rates

Within a single climate zone, it may make the most sense to put in a gas furnace in one location and a heat pump in another. Natural gas rates have been really low for a few years now, but that hasn't killed the electric heat pump. Look at Georgia, for example. Since deregulation of the gas industry here in the '90s, we typically pay about $30 per month in service charges. I've known people with gas heat and electric water heaters who get gas bills in the summer showing no gas consumption and an amount due of $30 or so.

One of the problems with comparing the cost of operating a gas furnace to an electric heat pump is that you're billed for each in different units. You pay the gas company for how many therms you use and the electic utility for kilowatt-hours. Then you've got to factor in the efficiency of the furnace. If you really want to know which is cheaper, you've got to do the conversions and find out how many cents per Btu you pay for each fuel, with the equipment efficiency factored in.

A more comprehensive analysis also would factor in the lifetime and maintenance costs of the different types of equipment. Still, with rates, efficiencies, and equipment costs all over the map, you can't make any generalization about always using heat pumps or always using gas heat. As Kai Ryssdal does every day on MarketPlace, you've got to 'do the numbers.'

Source of electricity

coal-fired electricity plant

If you're concerned about the environment, then you'd want to know something about the sources of your various fuel options. Natural gas has its fracking problems. Most electricity is generating by burning coal or natural gas. If you live in the Pacific Northwest, most of your electricity comes from hydropower, which is much cleaner but has disrupted river ecosystems and salmon runs.

Building a net zero energy home? If so, that makes heat pumps more attractive because the source energy issue isn't as big a deal, but it also depends on the array of incentives available to you to make the onsite power production feasible.

Heating high-performance homes

David Butler wrote a two-part series on the challenges of heating and cooling high-performance homes for us a couple of years ago. The first article was titled Just Say No to Furnaces in High Performance Homes and made the case that...well, do I really need to say?

The second article, Heat Pumps and Hydronics – A Great Team for High Performance Homes, laid out a path for using heat pumps in a way that overcomes one of their biggest drawbacks: electric resistance heat to supplement the heat pump at low temperatures. Yes, most heat pumps need supplemental heat. It's true. That certainly doesn't make them unacceptable, though. It means you need to be smart about how you set them up and use them.

As David described in his second article, using a hydronic coil with heat from a water heater is a much better option for supplemental heat than is electric resistance heat. You really should click to read the article.

These ain't your grandpappy's heat pumps

Heat pumps today aren't the same as the early models from the 1970s and '80s. They're more efficient. They've got the supplemental heat thing figured out. And they come in a wide variety of efficiency, capacity, and technology, from the standard models to mini-splits to ground-source heat pumps.

Of course, furnaces (and boilers) have come along, too. We now have high-efficiency, sealed combustion furnaces that can distribute the heat through either forced air or hydronics. You can get a modulating condensing (mod-con) furnace that can adjust the capacity closer to the needs of the house.

Overall, it's easier and less expensive to get a heat pump small enough to match the loads of a high performance home than it is to get an appropriately sized furnace. Mini-splits are great for this and allow for better zoning, too.

The shocking truth

In the end, you shouldn't go with a furnace just because an expert said all heat pumps are unacceptable. You've got to look at the issues I outlined above. Consider what your priorities are. Low energy bills? Environmentally friendly energy sources? Uniform heating with lower temperatures or short blasts of higher temperatures?

The shocking truth about heat pumps is that they might well be a great fit for your home. Or they might not. It depends.

 

Related Articles

Heat Pumps and Hydronics – A Great Team for High Performance Homes

Finding Balance - Heat Pump Heating Load vs. Capacity

How the Heck Does a Heat Pump Get Heat from Cold?!

 

Photo of power plant by eutrophication&hypoxia from flickr.com, used under a Creative Commons license.

Comments

John Semmelhack
Aug 23 2013 - 6:59am

C'mon Allison. You can't straddle the line on this one. Don't you remember the 14th rule of Building Science Fight Club? "Pick a side and fight to the death for it." 
 
This debate is akin to the great one of the ages: chocolate vs. vanilla, cats vs. dogs, Cubs vs. White Sox....and now heat pumps vs. furnaces. ;-)

John Nicholas
Aug 23 2013 - 7:45am

I had the pleasure of completing an audit for a Homeowner in Western KS! Far enough west you could throw a rock into Colorado and Oklahoma! (OK! 2 Rocks) 
 
When I got to the end of the interview, I found out they were getting gas from their own gas well. And it was running out. They were one of the last in their neighborhood to run out. Everyone
 
I made the recommendations to fix the enclosure and then choose a system. When I wrote out the essential differences between the 3 different types and compared to my notes on the audit, I learned why everyone is unhappy. 
 
The heat rise on the old furnace was specified at 150 - 220° F. The actual was 190° F. 
 
Everyone was used to coming in and getting that heat blast when they stood in front of the supply.  
 
The furnace model was not listed in Preston's. It may well have been original to the home (1945)!

Allison Bailes
Aug 23 2013 - 9:42am

John S.: Sure, I can! Despite how hot the debate got over this issue on LinkedIn, it's just not as important as making sure the toilet paper comes over the top instead of underneath. ;~) 
 
John N.: Their own gas well? Have they tried fracking to get more production? JK! Yeah, part of the decision-making process is understanding what you're used to and whether you're willing to adapt to something else. What did they end up deciding to do? 

John Nicholas
Aug 23 2013 - 10:01am

I have not been informed of work chosen. I called at 12 months after the audit and did not get a return to my message. I am not sure they looked for pricing. When someone does, I usually get a call from the contractor since my contact info is there. 
 
There were some other issues with the house they needed to resolve. Asbestos siding, basement wall issues, Radon, retirement. They may have sold and moved into town.  
 
Dealing with the royalty payments from the company that purchased the mineral rights was a separate issue. The payment (signed in the '40's) was free NG forever. There is no fracking activity within 80 miles of the location. It is outside the Mississippian lime formation. 
 

geoff
Aug 23 2013 - 10:20am

Clarification: ...find out how many cents per DELIVERED Btu you are paying... 
 
you mention the Linkdin debate, which is probably still ongoing, which might have made you think twice about the topic. Still you make great points, and present the correct thought process from economic point of view.  
 
Other considerations, some health and some purely subjective, include; 
* what cost to pipe the house for gas/lp? Typically $1,500 - several thousand dollars. And some appliances (all?) cost more up-front. Do we factor in this cost to the payback? 
 
* Does someone in home have health issues where we might find controlling temp, RH, and super sealing the envelop easier with all electric. 
* Yes, in certain ares, homes do have there own gas piped in from back yard. Or a big lake that makes geothermal much cheaper to install, or free pellets for a pellet furnace, etc. 
 
* I like a gas cook top and grill, so once I pipe those, maybe a small furnace, tankless WH with hydronic loop to air handler, or small modulating boiler makes sense.  
* Or, in a super low energy home, electric radiant heat? 
* and please do consider utility rate structure. In some areas, the local utility practically gives away electricity in winter. Don't apply an average rate. Determine what it actually costs to run the furnace. (And yes I can call both gas and electric heating a furnace) 
 
In summary - you are 100% correct to say "it depends" and not violate the fight club guidelines.

Allison Bailes
Aug 23 2013 - 11:13am

geoff: Good catch. You're absolutely right that it's the delivered BTUs that matter. I included part of that when I wrote that you've got to factor in the equipment efficiency, but I neglected to mention the distribution system efficiency. I've been meaning to write about delivered BTUs, and I'll get to that soon. LBNL did some work a while back on what they called TAR, for 'tons at the register' because a 3 ton AC usually doesn't deliver 3 tons. 
 
stan: Ah, someone noticed. Yes, I've been working on my headlines lately. This particular one, though, isn't one you'll see often here. It'll be at least a year before you see another headline with the shocking truth about anything here. 

Bob
Aug 23 2013 - 11:43am

Dont forget about that $30 month meter fee. tThink of it as the $360/yr it really is, even though most of the gas is only used 6 months or less per year. That brings the true cost closer to $60/mo when divided over the 6 winter months. Most high efficiency homes dont use enough fuel over the winter to justify the added $60/mo cost for gas.  
 
All of this of course varies by area, YMMV.

Amy Musser
Aug 23 2013 - 12:05pm

I'd just like to add the observation that if your "expert" is telling you that all equipment of a certain technology (for example, heat pumps) is unacceptable, then I would seriously question my choice of expert. I rarely see people whose professional opinions I respect making statements like this. 
 
I'd also like to second the observation that if we're talking about a very efficient home, that monthly service charge (usually $10-30) just to have gas hooked up to your house becomes a large percentage of your overall energy expense, and it may not be worth having multiple fuels. Also, in rural areas where we would be looking at propane, it's a lot less "price stable" than gas or electricity.  
 
Finally, this is one of many areas where you want to listen to what the "experts" say, and then consider how close they live to you. This question has a very different answer the further north you go and the higher your electricity costs get. Or if you "need" a backup generator, or want to stand over the register and get blasted with hot air, or a million other things.

Adam Gloss
Aug 23 2013 - 12:28pm

Why are we just talking about an either/or scenario here? In our market (Western WA), temperatures are fairly mild,and both natural gas and electricity are relatively inexpensive. In many homes, we recommend a dual-fuel or hybrid system - retrofitting an air source heat pump with a gas furnace. this provides the best of both worlds: High efficiency electric heating with the heat pump when temperatures are mild, AND fast recovery with high efficiency gas heating when temperatures are colder.  
 
I fully agree that the decision is an individual one based on a wide variety of factors - including what makes the homeowner most comfortable. there are a wide range of options, and a single one is not right for everyone. But sometimes in life, you can have your cake and eat it too.

Bob
Aug 23 2013 - 2:00pm

In our area with current gas/electric rates a dual fuel system doesnt makes sense. If you are going to spend $30/mo to have gas hooked up then use it. Gas rates are running about 50 cents per therm while electric is 10 cents per KWH for the first 600KWH and 6 cents per KWH thereafter. Even at 6 cents per kwh its hard to justify when gas is only 50 cents per therm. The gas company builds all the deliverly charge into the $30 monthly fee.

David Butler
Aug 23 2013 - 2:44pm

With gas natural prices low, I've been specifying gas furnaces more often lately (man, I wish mfrs would offers smaller burners with wider CFM range), but I still encourage clients to pay the few hundred dollars extra for a heat pump vs. straight AC to protect against future price volatility. 
 
When natural gas isn't available, heat pumps are usually a no-brainer. In order for propane to make sense as the primary heat source, the per gallon price would have to be reliably less than ~9X the marginal winter electric rate. In fact, in some markets, it costs more to heat with propane than with electric resistance. 
 
The key is to learn to do the BTU math. For example, be sure to add blower energy for furnaces. BTW, Geoff brought up the issue of delivered BTU, however, when comparing a heat pump with a furnace, duct system efficiency may not be relevant. In new construction, I only consider cost-per-BTU of heat produced.  
 
Unfortunately, estimating the supplemental fraction is more art that science. This is where experience trumps straight math.

Curt Kinder
Aug 23 2013 - 8:25pm

Santa Gas is coming to Town? 
 
There's a big push in my area (northeast Florida) to get residential customers to sign on with the expanding gas grid.  
 
A marketing guy with a local utility (which also sells propane, for now) approached my builder partner with a proposal to put gas appliances in his new homes. In the interim, they'd be fueled by propane and later converted to NG when the grid appeared at the doorsteps. The utility guy promised a lowered propane price to sweeten the offer. 
 
With all the hoopla over cheap NG, it is easy to be wooed by this idea, but I'm convinced that the devil is in the details, in particular, meter fees. I attempted to read the utility's 100 page tariff, but got bogged down in the details of unspecified surcharges that would apply to meters in "expansion areas" 
 
Further analysis of each energy center for which gas might be a choice in north Florida: 
 
1) Heating - not so much. Heat pumps rule since cooling loads here are such that a properly sized air source heat pump rarely needs its heat strips in a reasonably tight house. 
 
2) Water heating - heat pump water heaters work very well here owing to favorable ambient air temperatures and lower than average water temperature setpoint (115-120) 
 
3) Cooking - I try very hard to dissuade clients from gas cooking owing to substantial waste heat and humidity thrown off into the kitchen, not to mention IAQ concerns in tight homes. Induction offers the same tight control and far higher efficiency. 
 
4) Clothes drying - gas does offer an operating cost advantage 
 
5) Outdoor grilling - gas is the obvious choice for all but the most die hard charcoal or alternative aficionados 
 
6) Standby electric generation - gas is certainly a preferred choice for generators. 
 
It is received wisdom that natural gas costs just 1/3 as much as propane on a btu basis. but applying that wisdom to homes with low annual gas btu requirements ignores the impact of meter fees. 
 
Grilling steaks and exercising a standby genny uses very little fuel so propane, even at 3x $ of nat gas may actually cost less after meter fees are factored. 
 
I do occasionally encounter audit clients who pay $5 or more per gallon for propane, but that's because they fell for the siren song of a rented propane tank, a license to steal since a rented tank may only be filled by the propane company that owns it. 
 
Buy the tank, play the field. 
 
 

Curt Kinder
Aug 23 2013 - 9:55pm

I have no technical objection to that recommendation. That such a small amount of fuel is typically needed supports the point I raised above. 
 
I'm a bit hazy on the NFPA or mechanical codes that might pertain to permanent use of 20# tanks adjacent to a dwelling, but use of permanent code-compliant regulators may well suffice. 
 
Most of my gas gourmet clients would not tolerate the downmarket appearance or regular hassle (even if just every 2-4 months) of schlepping and wrenching on grill tanks

David Butler
Aug 24 2013 - 6:54pm

> Most of my gas gourmet clients would not tolerate the downmarket appearance or regular hassle (even if just every 2-4 months) of schlepping and wrenching on grill tanks  
 
What's the alternative? No one's going to accept a 20-25 gal/yr delivery account, so the homeowner would have to haul a 100 lb tank.  
 
Not sure about code, but the local client who did this installed the same regulator (on the house supply line) that would normally be used on a permanent tank. It was just a matter of configuring the quick connect.

Aaron Stein
Aug 27 2013 - 1:04pm

If you want to take a big-picture look at broader environmental impacts it is important to look at site and source energy. Since ~2/3 of energy is wasted in T&D; of electricity it isn't really fair to compare a gas furnace and heat pump at the point of use.  
 
A high-efficiency furnace seems to be the clear winner from that perspective, especially if electricity is produced through burning natural gas (thereby rendering the fracking debate irrelevant - at least in part).  
 
This is more clearly delineated in the commercial realm, where site and source energy are both calculated independently (e.g. EPA's Portfolio Manager).

David Butler
Aug 27 2013 - 3:47pm

Aaron wrote:  
> A high-efficiency furnace seems to be the clear winner from that perspective 
 
Not so fast. Even if 2/3rds is wasted by T&D; (obviously varies by location), a mid-efficiency heat pump would consume about the same or less than a high efficiency furnace.  
 
n.gas T&D; efficiency = 95% 
furnace efficiency = 95% 
total source efficiency = 90% 
 
electricity T&D; efficiency = 33% 
heat pump efficiency* = 300% 
total source efficiency = 100% 
 
* assumes 3.0 COP above the thermal balance point. In a dual fuel config, source efficiency would be 90% below the balance point.

Bob
Aug 27 2013 - 4:08pm

The problem with NG is the fixed portion of distribution costs. With a $30/mo $360/yr meter/delivery charge, NG doesnt make sense in many high performance homes.

Bob
Aug 27 2013 - 4:13pm

Another issue with heat pumps is they require 400cfm/ton in order to ger thier rated COP. Most systems average 260cfm/ton in the real world. Gas furnaces arent as sensitive to low airflow unless its bad enough to trip the high kimit switch.

David Butler
Aug 27 2013 - 4:43pm

Bob wrote: 
> Most systems average 260cfm/ton in the real world.  
 
I don't know where you got the statistic, but poor design and installation practice in existing homes doesn't seem relevant. Presumably the folks reading and participating in this blog understand the importance of airflow and are among those who follow best practices.  
 
That said, once there's enough airflow to fully condense the refrigerant, the benefit of additional airflow largely depends on blower and duct system efficiency, same as with a furnace.

Bob
Aug 27 2013 - 5:12pm

Sort of... The pressure required to condense all the refrigerant will vary with airflow. Higher pressure required will mean a lower efficiency unit.  
 
Airflow may be optimum at first installation bt will fall as the system ages and dirt collects on the evap coil. In the real world evap coils are rarely cleaned once they are installed. 
 
Then there is the charging procedure, proper vacuum and correct refrigerant charge are critcal in heat pump applications. Rarely are systems charged optimally. Backup heat takes up the slack and the customer never calls for service.  
 
None of these issues affect gas furnace efficiency..

grandma Betty
Mar 22 2014 - 11:08am

i have had natural gas heat for around 20 yrs now. The heat is warm and I use it for cooking too. My home is 72 degrees most all of the time summer and winter. I am on a budget plan with the company I buy service from. it is good to ask if there is a budget plan now days so you can budget your pennies wisely and have enough left to pay the bills...winter is especially good for the budget plan because instead of it going up and down, it stays the same all the time. Mine was around 152 a month for gas and electric. They do show how much you used, and sometimes you use a lot less than you are paying for but that is to pay for the bill for the winter months when everyone else gets those outrageous bills, yours will still be 152 or what ever your analysis comes up for a probably 6 months rate. For the best results from all types of systems plan ahead, nothing is free!

Ted
May 29 2014 - 2:09pm

How does the construction of a home determine whether or not I should use a heat pump or a gas furnace? I know that my natural gas furnace will operate at its rated efficiency at pretty much all times. The question is really how many hours will the outdoor air temperature allow my heat pump to operate at an efficiency greater than that of the furnace. For us in MN, it makes little sense to put in air to air heat pumps but I know of projects that do. What I have seen is a dramatic drop in COP when the outdoor air temperatures drop below 30 - 40 degrees.  
 
The question of the house construction seems pointless. If i need one btu of gas or electric, a btu is a btu. Its a matter of what system can deliver that btu most efficiently over a heating season.

geoff hartman
May 29 2014 - 3:48pm

Ted - I think you mean "which system can deliver the btu least expensively." A heat pump is almost always, more efficient - at least if we consider site energy. It may often be less expensive, and possibly more comfortable, even in parts on MN. Calculate the seasonal cost of each, and remember to include service/meter costs that can be significant and will occur even if you use no gas. In new construction &/or additions, consider piping expenses as well. If no gas is needed, the gas distribution system is an additional savings. 
 
Your final answer includes more than cost however. Servuce availablity, comfort, health (may not be wise to install combustion appliances in a well sealed building), air quality, fuel availability and reliability, convenience, and aesthetics can all outweight the cost concerns. Cost is the only item we can calculate though! ;) 
 
That's where construction may come in. Yes, a btu is a btu, but the better/tighter/lower peak load building may probably perform well with a heat pump, one poorly sealed with high peaks in winter will almost certainly not. Too much auxiliary demand and imbalance between summer/winter loads, among other design issues.

David Butler
May 29 2014 - 4:57pm

@Ted, amplifying on what Geoff said, I agree that heat pumps are not a good match for poorly insulated homes with a leaky envelope. In general, the more efficient the envelope, the more sense a heat pump makes. Furnaces (which are often grossly oversized in low load homes) can cause comfort issues due to the large contrast between supply air and ambient air. Heat pumps have lower supply air temps and much long cycles, thus ensuring more even temperature distribution. In any case, it's important to position diffusers so they're not directed toward seating areas, etc. 
 
The economic rationale for a heat pump depends on the thermal balance point (e.g., intersection of heat pump output curve vs. house load curve, plotted against ODT), below which a heat pump requires supplemental heat. If a home has actionable cooling and moisture (RH) loads, oversizing the heat pump more than 25-30 percent above the cooling load is a bad idea. The economic rationale also depends heavily on local fossil fuel options. As noted in my initial comment, heat pumps are a no-brainer when the alternative is propane (or fuel oil). Keep in mind that even at 0F, a mid-efficiency heat pump will have a COP of around 2.0. The only question is the method of providing supplemental heat. First-costs for dual-fuel vs. electric often weight heavily in this. 
 
With today's low natural gas rates, the break-even outside point (ODT) may be high enough to make NG more attractive for space heat. But the calculations are more complex, as it's necessary to first develop the heat pump's COP curve from the manufacturer's expanded data tables. But keep in mind that a heat pump only costs a few hundred dollars more than an air conditioner. Also, it's interesting to note that there are more heating hours above freezing than below. This is especially true in northern climates due to long heating season.

Marshall
Jun 23 2014 - 6:17pm

I can do the cost figures but since I have no experience with heat pumps one question remains unanswered. Can a heat pump provide 76 degrees when outside tempature is 40 degrees. We like 
to maintain 76 degrees all the year around. I have been told by 
a heating and Air contractor that 
the maximum heat you can get from a heat pump is 70 degrees without a supplement source. Tru or False? 
 
Second question - does it feel the same as a furnace heat?

David Butler
Jun 23 2014 - 10:49pm

@Marshall, whether or not a given heat pump can bring your house to 76 at 40F outside temp depends on size of the heat pump relative to your home's heating load at those conditions. But if your home is relatively tight, well insulated and has double-pane windows, a 36 degree delta from 40F is well within reason. 
 
Here are some anecdotes: The 2-ton heat pump in my previous home could maintain 70F at 28F without supplemental heat. My current home has a somewhat oversized heat pump and is able to maintain 70F when outside temps drop to 20F. 
 
But in an older leaky home, a 30F to 35F outdoor-indoor delta is about the limit, depending again on size of heat pump vs. the home's heat load. Keep in mind that beyond the limit, the heat pump continues to product the lion's share of the heat, sloping off as outdoor temps drop further. Supplemental heat alkso keeps the supply air temp from dropping too low. 
 
As for whether a heat pump feels the same as furnace heat... I should certainly hope not. At least in efficient homes, furnaces can create comfort issues due to the extreme contrast between supply air temps and ambient air temps when furnace cycles off. Furnaces can produce supply air temps as high as 140F (although this can be reduced by increasing airflow, and contractors are learning the benfits of lower supply air temps in today's more efficient homes). In any case, if you keep your house at 76F (I hope I never have to visit you in winter!), a heat pump's supply air temp should stay above 100F when it's 40F outside. But even a 15F rise is comfortable in an efficient home as long as diffusers are adjusted so as not to direct air toward standing or seating areas, or beds.

Scott
Aug 9 2014 - 9:58am

Next year I'm building a new house in the mountains of southern Pa. It will be 1,800 sq/ft on the main floor, lots of glass to the south (for the view) & half the basement will be finished. It will be properly insulated (using foam). 
My first thought was Geothermal heat but do to the expense, I'm now thinking Heat pump w/propane backup. I will have an underground propane tank for stove top, outdoor grill, fireplaces, generator & maybe hot water. Question 
Any concerns with my plan? 
Geothermal vs heat pump/propane ? 
Cheapest (& best) hot water ? I would consider solar hot water. 
 

David Butler
Aug 9 2014 - 1:20pm

@Scott, depending on local energy costs, it often costs almost as much (if not more) to heat with propane than electric strips. Even in markets with higher-than-average electric rates, the savings may not justify the high first-cost of a dual fuel system when fueled by propane, especially in a tight, well insulated home that have a small supplemental fraction.  
 
The key is to keep supplemental heat to a minimum by getting the envelope as tight as possible. I strongly recommend including an air sealing specification (e.g., not-to-exceed blower door target) in your contract. Also, it's always a good idea to have an independent thermal bypass and insulation inspection to ensure you're getting what you paid for. 
 
As for geo... in my experience, if you do a good job on the envelope, geo usually doesn't pencil out. But again, it depends on the particulars. Ditto for solar hot water. 
 
The best advice I can offer is to seek professional guidance. There's too much at stake to make these decisions without proper analysis specific to your project.

Gordon
Aug 13 2014 - 12:49am

Do not forget PV solar panels with a grid backup and a bank of batteries. That changes the equation plus don't forget the incentives.

Gwen Nichay
Mar 3 2015 - 2:12pm

I need some answers here. We recently purchased a house that had a heat pump ready to be picked up. We were excited by the fact that we were going to have a great heating supply there's also going to be cheap. well our heating and air guy said he was to busy else where atm to hook up the pump. So he bypassed the heat pump and hooked the emergency burners(heat strips) up to run full time. I was first concerned that is going to burn up the heat strips and I was going to end up paying more money in the long run. I'm already a thousand dollars into the sky and he's doing it because he's our friend. Which makes this next part difficult. he told me when I asked him as to why I got a $500 electric bill this past month and if it had anything to do with the heat strips being hooked up full time. he said no that I would be more then surprised to know that it would cost me more money if I have the whole system hooked up heat pump and all. well I'm not an idiot but I really think of this guy just doesn't know what he's doing. Because it doesn't make sense to me how they can market a product to be energy efficient and sell as much as they do love them and you're supposed to expect a $500 a month electric bill or more to save the environment.please somebody tell me I'm not an idiot and this guys jerking me around.

geoff hartman
Mar 3 2015 - 4:16pm

I see several comments about NG or LP possibly being less expensive option as suplimental heat source. - Remember that in new construction you could soend several thousand $'s to pipe the gas, and then there is a monthly service/meter fee. Furnace also costs hundreds - if not thousands - extra for equipment, venting, CO sensors throughout home, eetc. It's usually cheaper to build house right abd go all electric HVAC.  
 
Existing homes may still have increased equip. cost,monthly service/meter charge and upgraded venting, and sensor costs.  
 
TO: Gordon - Find someone to fully optimize that Heat pump and you could save 50% to 75%, or more, on heating cost. Friend or not, your heat strips are very expensive option.

Dean
Apr 5 2015 - 1:10pm

Solar electric (not a fossil fuel)is getting cheaper every year. Heat pumps get more efficient every year.  
 
~Thus~ 
 
Heat pumps will meet solar in the middle. Gas will be left out in the cold

William Steadman
Apr 13 2015 - 3:10pm

I had a ACADIA heat and cool furnace, N W Pa. 4 ton. worked great for Five Years. Quit defrosting. Dealer said it was junk. Now I have 4 ton Bryant, back up elec. ran almost all winter. Very expensive. So is there a Furnace like the ACADIA on the market now ?

David Butler
Apr 13 2015 - 10:06pm

@William, the Hallowell Acadia was unique in the residential market. It had a booster compressor that provided the extra capacity at lower temps. Your 4-ton model had perhaps as much capacity at cold temps as a six ton conventional heat pump. Too bad Hallowell didn't survive. I never specified one because I thought it was overpriced and also because I tend to steer clients away from new technologies and small manufacturers. Simply too much risk.  
 
There may be other ways to significantly reduce the amount of supplemental heat your system requires. But in terms of other heating options, assuming you don't have access to natural gas, you may want to consider a ducted mini-split. Mini-splits (especially hi-heat models) have significantly more capacity at low temps than their conventional counterparts. They accomplish this with a variable speed compressor that's larger than what the nameplate suggests. Cooling capacity is electronically limited to nameplate in order to qualify for the nameplate AHRI rating, but in heat mode, the inverter driven compressor can open up to maintain capacity at the lower temps.