furnace vs heat-pump
With winter time coming up for the Phoenix Metropolitan, citizens have the choice between, heat pumps and gas furnaces. They are two great and efficient options for heating. While we’ve noticed some of our customers try to avoid using their heat, there is more than likely going to be times you need it, we know we do. We’ll compare the efficiency and disadvantages of the two and help you decide which will be best for you.

Why Heat Pumps

A lot of our customers have heat pumps in Phoenix because they can cool or heat in one system, they heat efficiently, and because the mild weather is perfect for them to operate properly. In cooling mode the system picks up heat from inside the home and removes it outside and in heating mode it picks up the heat from outside and brings it inside. Some people like them just because they think they are more comfortable than furnaces.

How Efficient Heat Pumps Are

The heating efficiency of heat pumps is measured in H.S.P.F. (heating seasonal performance factor), the higher the rating the more efficient the system. It is a ratio of B.T.U. (British thermal units) heat output over the heating season to watts per hour of electricity used; electricity in Arizona is about 12¢ per kilowatt hour. They can produce about one-and-a-half to three times as much heat than the electrical energy it consumes because it uses that energy to pick up heat that is already outside and brings it inside. A heat pump with an H.S.P.F. rating of 8 will cost about $15.60 to produce 1,000,000 B.T.U.’s. That many B.T.U.’s is equal to 293 kilowatts but since the heat pump is using that energy to move heat it actually is using 130 kilowatts to deliver that much heat. That’s why heat pumps are more than %100 efficient and need H.S.P.F. to measure system heating efficiency.

The Disadvantage Of Them

They don’t perform well when it gets really cold because they remove heat from outside and when it removes so much, the coils outside freeze. The coils freezing prevent any heat transfer until defrost mode kicks on. Basically, the system switches back into cooling mode to bring heat to the outdoor coils to defrost them, this temporarily causes cold air to be blown inside. With heat pumps in Phoenix you face a disadvantage of possible moments of cold air just due to its normal functions.

Why Gas Furnaces

We’ve noticed our customers use gas furnaces because it never gets too cold for them to operate in Phoenix. You never have to worry about the unit blowing cold air (unless there is a breakdown) since it can operate in colder temperatures. For furnaces, natural gas is combusted to produce heat. Similar to heat pumps, some people like them just because they think they are more comfortable.

How Efficient Furnaces Are

The heating efficiency of gas furnaces is measured in A.F.U.E. (annual fuel utilization efficiency); it scales from around 80% to 97% efficiency. The cost of natural gas in Arizona is around $12 per one thousand cubic feet of gas combusted to produce heat, which is equivalent to producing 1,000,000 B.T.U.’s. A furnace operating at 80% efficiency is going to cost around $14.38 to produce 1,000,000 B.T.U.’s since it is not 100% efficient and there is gas that is not converted to heat. Most of our customers in Phoenix, who have furnaces, use the 80% ones because heat isn’t necessary most of the year and the low equipment cost. Even though the heat pump is more efficient it is actually slightly cheaper for a furnace due to the cost of gas in Arizona.

There Is a Couple Disadvantages

Unfortunately, gas furnaces do carry a few risks. For starters if a leak was to occur and a lot of gas filled your home, the gas could cause an explosion. That’s why natural gas is given an odor, just in case of a leak, you can smell if its leaking so you can have have an expert out to prevent any problems. Another risk is carbon monoxide poisoning due to a malfunctioning furnace, however, carbon monoxide detectors can easily alert you at its soonest presence. Even though there’s some crazy sounding risk, there is low probability either will ever occur so long as you maintain your system and take necessary precautions.

What It All Depends On

Factors aside from the system itself that effect efficiency, is how well the home and the ductwork is sealed up and the design of the system. All the work your equipment puts into your home doesn’t matter if heat can’t be distributed good. Ductwork leaks will prevent systems from reaching maximum efficiency because air will be lost in the attic. Other than the ductwork your home can be leaking and preventing optimum efficiency due to the sealing of windows and doorways. If the system wasn’t designed well or improperly installed it is probably not operating correctly and preventing optimum efficiency. You may have an efficient unit itself but it just might be that other components and factors are preventing maximum efficiency.

One Quick Tip: A programmable thermostat can help save money on the utilities by operating the system at different temperatures at different times of the day depending on what you have scheduled.