Gas Heat vs. Heat Pump

Heat Pumps are an ideal heating source for the Florida environment. Read more
to find out about the differences between gas heat and electric heat for your
swimming pool.

Contemplating the Advantages of Heat Pump vs. Gas Heating
for Swimming Pools & Spas in Florida
A heat pump should be considered the ideal and primary source for pool heating.
The pitfall to avoid is recommending a Gas Heater in error and in this case, there are two specific scenarios to avoid: one is residential and one is commercial. In either case, the dissatisfaction will be traced back to the doorstep of the business that sold it to them.

  • Residential Gas Purchase may result in:
    The homeowner investing the money in a gas heater and either incurring outrageous operating cost or opting not to use the heating as much as they would like, resulting in less overall satisfaction in the heater purchase and the usage of their pool.
  • Commercial Gas Purchase may result in:
    Blind usage of a gas heat source resulting in high unnecessary operating costs that could easily be reduced by several hundred percent.

Once the consumer has committed to the major investment of a swimming pool, it is a wise decision to heat the pool for maximum pleasure and usage. A heated pool is not only more enjoyable overall it also extends the swimming season by several months, giving pool owners a greater return on their pool investment.
There are several methods of pool heating to consider. Solar, Heat Pumps, Resistance or Gas – either Natural or Liquid Propane.
In this essay, focus is on the comparison between Gas Heat and Heat Pump methods. Gas Heating’s two most attractive features are speed and ability to heat in any weather condition; it is not dependent on the air temperature.
In the vast majority of cases, these two features are minor and largely irrelevant conveniences, once true operating cost is considered and usage of a heat pump are understood.
Conversely, there are specific situations and usage patterns that benefit from a Gas heater or from usage of the gas heater in combination with a heat pump. In most situations, however, gas heat is misused, used inefficiently and under incorrect assumptions that can cost a homeowner or business much more money than is necessary to achieve a heated pool. It’s necessary to understand the heat sources in order to make the most sensible choice.
Operating Cost
It costs 6-7 times more to operate a Gas Heater versus a heat pump. For example, to heat an average size residential pool, in South Florida to 88 degrees and keep it heated to that degree consistently throughout one year will cost approx $700. To heat the same pool with a gas heater will cost the homeowner approximately $4000 to $5000.
This is simply not a cost that most homeowner’s will want to incur to heat their pool. And while it seems the result would be a giant bill for the homeowner using a gas heater, the reality is that the homeowner simply refrains from using the heater nearly as often as they would like. The cost of heating the pool then becomes a luxury cost and an expense that the household cannot or will not bear.
The homeowner, in most cases, is where he was when he began – unable to fully enjoy a comfortably heated pool at his convenience due to exorbitant operating cost. Well, he’s not quite where he began. He’s now also out of pocket on the cost of his gas heater.
Considering the commercial pool, similar issues are at hand, but operating cost may not be as prohibitive due to commercial budgets and needs. The question at this juncture is – should the operating cost be excessive simply because it’s in the budget? Or can the operating cost of gas be diverted to other expenses for the property? For example – should a homeowner’s association set aside $20,000 per year to operate the gas heater for the year – or understand their options with a heat pump, spend approx $4000 for the year, and allocate $16,000 for other community improvements?
Speed of Heating
How quickly the pool is heated is a major topic of debate when considering heat pump vs. gas, although upon further consideration, speed becomes completely irrelevant.
A heat pump will not and does not intend to compete with a gas heater on speed and it is not the heat pump’s purpose. Let’s start with a fixed example and compare: A new residential pool, size 14 x 28 brand new and has never been heated; its heat is being gained for the first time and the desired temperature is 88.
The heat pump will elevate pool temperature to the desired temperature in about a day to a day and half and the heat is achieved. Initial heating of the pool is not simply a matter of heating the water. All the concrete surrounding the pool is cold, and must be “heated” along with the equipment that the water runs through. In other words, at initial heating, everything is cold, not just the water.
Once completely heated, the heat pump continues to run and operate, shutting off at desired temp, and kicking on to maintain, and runs continuously. It operates almost identically to an air conditioner, which, once temp is achieved, operates to maintain that temperature.
For example, it is not at all the habit for the homeowner to leave the house each morning, completely shut the air conditioner off, then return home in the evening and hope it cools it as quickly as it possibly can. The purpose of the AC is to achieve the temperature, and then maintain the desired temp. It may be lowered or increased as needed, but rarely is it shut off completely. It is the same with the heat pump.
This is also worth mentioning in regard to usage of a Gas heater. By shutting it completely off and on, it now carries the additional load of having to entirely reheat the water, concrete and all equipment each time.
The heat pump is intended to achieve the heat, and continue to maintain. The heat pump will not come to the table to compete with the gas heater on speed – the same way a car will not intend to compete with a helicopter for speed. To put it plainly, it cannot compete but it is also not its purpose.
One the heat is achieved; there is no need for “speed of heating.” The pool is always heated, always ready and always at the perfect temperature. THAT is the heat pump’s advantage and purpose. Then factor in the enormous cost difference and again, considering the intention of the heat pump, speed is not relevant because it’s just not needed. The heat is always there. Convenience now has a new definition.
What about the spa?you ask.
In a residential scenario, the homeowner is a creature of habit in most cases. He most likely has a pattern of usage with his spa – perhaps he knows that he entertains on Saturdays or enjoys a soak every evening with his wife after dinner.
The heat pump has a dual thermostat and can be equipped with an automatic timer. It’s a matter of pressing a few buttons one time to program the heat pump to begin heating the spa at the desired time per their schedule. If he soaks at 6pm every day, program the timer to divert around 3. At 6 every day the spa is ready to go, right on schedule. Again, convenience is absolutely uncompromised. With the spa always hot at 6 and a civilized operating cost, convenience is in fact, enhanced.
What about speed in a commercial setting?
Considering the commercial swimming pool in Florida, a heat pump will still be preferable for both efficiency and cost. The heat pump’s limitation here will be that it cannot operate below 45 degrees air temperature. At luxury spas and resorts, the high-end customer may demand to swim, regardless of the temperature. And the luxury business will deliver this amenity at any cost. Even under these conditions and circumstances, a heat pump will still carry the major bulk of operating cost, keeping this figure reasonable. Since cost is not necessarily prohibitive, it is advisable to also incorporate the gas heater as a back up heat source, utilizing it to “pinch hit’ for the heat pump in the colder temperatures.
Again using the car and helicopter metaphor in this scenario, it makes sense to use the car for daily use, but incorporate the helicopter only when needed. Cost is vastly greater to operate the gas heater, but its advantages are now incorporated in a way that is sensible and affordable when used in this way. Desired water temperature is always available, and now achieved under better management of resources, i.e.: money.
This scenario does not exclude usage of the gas heater, but in fact incorporates it in a much more cost effective and conscientious way.
Let’s consider the commercial setting for spas. There is no habit pattern to speak of because of the nature of its use. Guests will come and go at any and all hours and want the spa heated randomly. This is another scenario where it is still more energy efficeient and less operating cost to continually run a heat pump. This keeps the spa at the desired temp at all times. Gas heat would still be recommended as back up in colder temperatures.
Although this stands as one of the few examples, it is still not an example that always calls for the gas heater. It could be the case that it is STILL less expensive to install a heat pump, and let it run continuously at high temperature, and it would be advisable to run a cost analysis to determine.
In summation, a heat pump in more than 90% of cases will be the most logical, cost effective way to heat a pool in Florida. The heat pump begins its heating process by taking heat from the air. With Florida’s warm ambient temperature and almost constant humidity, it’s an extremely sensible choice. Gas heat, while effective, comes at a cost that is 600 to 700% higher and tries to justify the expense by offering conveniences that when truly examined are not relevant as they are available with a heat pump through basic knowledge of how and when to operate the heater.
Aside from speed and weather issues, there are other factors to consider when comparing gas heating to a heat pump. The life expectancy of a typical gas heater is 3-5 years versus a heat pump with a life expectancy of 7 – 10 years. A gas heater also is built using steel burners, and copper lines which due to the nature of pool chemistry will degrade causing regular maintenance issues as well as a steady decline in BTU output over time.
The heat pump utilizes a titanium heat exchanger which is not only more effective in the heat transfer process, but will never corrode or wear out and has a lifetime warranty.
Add to that the additional inconvenience of propane refills, which, if the owner can afford to run the heater regularly will require refilling the tank approximately every month.
Handling of gas in general also adds a risk factor due to the possible danger due to the explosive, flammable nature of the gas.
While it’s already clearly established that cost to run a heat pump is lower than running a gas heater, there is the additional consideration of rising costs in the future. What it costs to run gas today may not be what it costs tomorrow. This could also be said of the heat pump, however, historically and traditionally electric prices tend to be more stable and increase less often than gas prices. In light of current gas and oil prices, price increases are even less possible to predict than usual.
Gas heaters are also responsible for a much higher CO2 output, making them less environmentally friendly, less “green” than the heat pump.
Both sources will provide a heated pool, but the heat pump is clearly the most grounded choice.