HVAC-Natural Gas or Heat Pump?

[msk1986911]

We live in the mid-Atlantic region (Maryland) and are strongly considering updating our heating and AC. The house is approx.2,400 sq feet. The heating system is an electric heat pump sized for a house of about 2,000 sq ft (we had an addition built last year and expected to have to do something with the heating /ac at some point; the $650 electric bill last month was a great motivator). My basic question is, is gas more efficient than electric? Does anyone have electric as the primary heat source and gas as back-up heat? Does anyone have an opinion as to which brands are better? The brands in question are either Carrier, Trane or Rheem.

Thanks for any insight.

Mike

[IROC]

I only have opinions, but here goes: IMHO you're a bit far north to rely solely on a heat pump for heat. They really lose efficiency at low temps and the auxiliary heat (not very efficient and costly) will be called upon too often. I've had both and I would not trade gas heat for anything. Gas heat is relatively expensive (but in your case maybe not), but it heats the house faster and the temps coming out of the vents are actually warm. It's very nice.

Our house is 2400 sq ft in Knoxville, TN (probably slightly warmer on average) and our combination gas/electricity bills are less than half what you are seeing.

[Jim Richards]

Mike, I agree with what Mike said.

[willtel]

Go gas fired. I live in Atlanta and I feel we get too many sub 20 degree days for a heat pump. Maybe if you were in Florida.

[billybek]

As mentioned above, heat pumps do a great job as long as they have warm ambient temperatures to work with. As the temperatures drop so does the ability for the unit to heat effectively.
Look at getting a high efficiency nat gas furnace and a matched coil and condensing unit.
That ought to cut down on your monthly output for energy. It isn't going to be cheap, but the payback time will be short with the amount you are spending each month on your electric bill.
Keep in mind, that monthly bill also includes the rest of the operating expenses of the house, lights, laundry etc... What amount do you spend for power when you are not running the heat pump for heating or cooling? Check your past bills for the lowest months for consumption, that should give you an idea as to how much it is costing to run the current system and what a projected payback time would be.
If your due to replace the old system anyway due to repairs or deferred maintenance, just spend the money and go all new. It will save you $$ during the cooling season too.

[old man neri]

Ground source heat pump maybe?

[red-beard]

Originally Posted by IROC

Gas heat is relatively expensive (but in your case maybe not), but it heats the house faster and the temps coming out of the vents are actually warm. It's very nice.

Gas Heat Expensive? Compared to what? Natural Gas is the least expensive way to heat anything in this country. Just look at the cost of running a NG hot water heater vs. electric.

Since you have a forced air setup, you should be able to get it retrofitted for a Natural Gas burner. This assumes you have natural gas in your home. If you don't it may be costly to run the gas line. In the long run, changing your heating system and hot water heaters will pay you back.

[IROC]

Originally Posted by red-beard

Gas Heat Expensive? Compared to what? Natural Gas is the least expensive way to heat anything in this country. Just look at the cost of running a NG hot water heater vs. electric.

Compared to a heat pump. When I lived in Alabama, I had one house that was full electric (heat pump) and then another that was gas heat/heat pump for AC. Our max power bills in the winter for the heat pump house were around $140 (and that's obviously for everything electric, but our electric rates are low - TVA). When we moved into our house with gas heat, the gas bills alone in the winter were sometimes $250.

So, gas heat in Alabama is more expensive than a heat pump. But it sure is nice...

[berettafan]

Live in Md as well and my understanding is a hybrid unit (gas below xx deg., heat pump above) is the most efficient.

We have gas, it feels good, costs a lot, and is very, very dangerous. I say that because it can a)blow up, b)poison everyone in the home, c)...well who needs c when a and b are what they are.

[berettafan]

Originally Posted by red-beard

Gas Heat Expensive? Compared to what? Natural Gas is the least expensive way to heat anything in this country. Just look at the cost of running a NG hot water heater vs. electric.

Since you have a forced air setup, you should be able to get it retrofitted for a Natural Gas burner. This assumes you have natural gas in your home. If you don't it may be costly to run the gas line. In the long run, changing your heating system and hot water heaters will pay you back.

says the man from texas.

[red-beard]

I expect it had more to do with the design of the house in Alabama, than the heat pump. Or, you were merely heating from outside temps of 55-60 outside.

A heat pump is nothing more than an Air Conditioner run backwards. If you have a local heat sink (water) the system can work very well.

If you are using air as the heat sink, you get a double hit. As the temperature differential increases, you need to transfer more heat, but the heat sink becomes less efficient.

San Diego is an ideal place for a Heat Pump. While I lived there, the outside temp at my house never went below 39 F in the winter, and never above 85 in the summer. And in the winter, the temp would reach 60-65 during the day and in the summer, it would drop to 65 at night. You would run the system a minimal amount of time, and you have a significant section of the day where the delta is so small, that a heat pump is very very good.

For heating, the problem is that below about 20F outside temp, the effectiveness and therefore cost of operating the heat pump exceeds that of running electric resistance heating. And since NG runs about 1/3rd the cost of electric resistance heating, the break point for heatpump vs. NG is somewhere between 40-50 F.

[red-beard]

Originally Posted by berettafan

Live in Md as well and my understanding is a hybrid unit (gas below xx deg., heat pump above) is the most efficient.

We have gas, it feels good, costs a lot, and is very, very dangerous. I say that because it can a)blow up, b)poison everyone in the home, c)...well who needs c when a and b are what they are.

How many houses which use Natural Gas for heating blow up each year?

Gasoline is far more dangerous than Natural Gas, since it takes a more energetic spark to ignite methane than gasoline vapors. Have you stopped running your gasoline car because it is dangerous? NG produces almost zero CO, without any controls. You car needs special controls and a double CAT to meet emmision standards.

[Jim Richards]

red, Mike's area gets dirt cheap electricity from TVA. Your area likely gets dirt cheap natural gas. Here in the Mid-Atlantic, it's all expensive. I think that it might be a bit cheaper to run natural gas for heat, instead of using electric heat to take over for temps below the range of the heat pump. Just my opinion.

[VincentVega]

Go with natural gas, or supplement with a pellet or wood stove. BGE dinged me for ~$350 last month. Ouch.

[red-beard]

I lived most of my life in Upstate NY and Western MA. I've had houses and apt buildings use a variety of heat sources. Maybe his $/kWh is extremely low. But most of us are paying much more than $0.10/kWh. And apts in upstate NY which used electric heat, were always much more expensive to heat, by a factor of 3, than those using natural gas. I converted my apt units to use NG, to make it easier to rent my places.

[berettafan]

Originally Posted by red-beard

How many houses which use Natural Gas for heating blow up each year?

100% more than do with heat pumps.

[red-beard]

So, when are you giving up your car? They are far more dangerous than a NG heater.

[red-beard]

From Wiki

Explosions caused by natural gas leaks occur a few times each year. Individual homes, small businesses and boats are most frequently affected when an internal leak builds up gas inside the structure. Frequently, the blast will be enough to significantly damage a building but leave it standing. In these cases, the people inside tend to have minor to moderate injuries. Occasionally, the gas can collect in high enough quantities to cause a deadly explosion, disintegrating one or more buildings in the process. The gas usually dissipates readily outdoors, but can sometimes collect in dangerous quantities if weather conditions are right. However, considering the tens of millions of structures that use the fuel, the individual risk of using natural gas is very low

on the other hand, electrical fires in the house...

Electrical fires in our homes claim the lives of 485 Americans each year and injure 2,305 more. Some of these fires are caused by electrical system failures and appliance defects, but many more are caused by the misuse and poor maintenance of electrical appliances, incorrectly installed wiring, and overloaded circuits and extension cords.
The United States Fire Administration (USFA) would like consumers to know that there are simple steps you can take to prevent the loss of life and property resulting from electrical fires.

During a typical year, home electrical problems account for 67,800 fires, 485 deaths, and $868 million in property losses. Home electrical wiring causes twice as many fires as electrical appliances.

My opinion: electricty is more dangerous than Natural Gas

[IROC]

Originally Posted by red-beard

Maybe his $/kWh is extremely low. But most of us are paying much more than $0.10/kWh.

Rates when I was in Alabama (especially the house with the heat pump) were around $.06/kWh. They're well below $.10/kWh even now.

[chuckw951]

I live in Maryland. We have two heat pumps. When it gets really cold outside they can't keep up. So I installed a Jotul stove (looks like a woodstove but runs on propane) for supplemental heating.