Finding the Best Pool Heater For Your Pool

By Karen White February 22, 2019 , , , ,


heated pool

When it comes to commercial pools there are two major options for heating, a heat pump or gas heater. When selecting either option you’ll want to look at the unit’s size, efficiency, and operating costs. Determining which option is best for your pool may also depend on the location and climate you live in. So let’s dive into a comparison guide on gas vs heat pump pool heaters.

Heat Pumps

Heat pump pool heaters are most effective when temperatures are above 45°F — 50°F. This is because heat pumps depend on outside air to generate heat. A heat pump pulls in air using a fan. The air passes over an evaporator coil where refrigerant in the coil absorbs any heat from the outside air as creates gas. This gas is then passed through a compressor increasing the temperature of the gas. This hot gas then passes through a condenser where heat from the gas is transferred to the pool’s water.

Size

Heat pump pool heaters are rated by Btu output and horsepower. Standard sizes include 3.5 HP/75,000 Btu, 5 hp/100,000 Btu, and 6 hp/125,000 Btu. A trained pool professional can help you determine which size is best for your pool. They’ll take into account the surface area of the pool and your location’s average air temperatures, as well as other factors like wind exposure, humidity and night temperatures in order to determine the best size unit for your community.

Efficiency

Heat pump energy efficiency is measured by it’s coefficient of performance or COP. COP is tested by running the unit with an outdoor temperature of 80°F and a pool temperature of 80°F. Although it may be difficult to compare COPs of different models because manufacturers may test each model differently. Generally, a COP ranges from 3.0 — 7.0. This means that for every unit of electricity used to run the compressor, you can expect 3-7 units from the heat pump

Operating Costs

The following table can help you to estimate the operating costs of a heat pump pool heater in your area:

Costs by Location of Heating Outdoor Pools with a Heat Pump*

LOCATION SEASON TEMPERATURE
78° 80° 82°
Miami 1/1–12/31 $1100 $1460 $1845
w/ cover 1/1–12/31 $215 $300 $410
Phoenix 3/1–10/31 $680 $875 $1090
w/ cover 3/1–10/31 $45 $85 $125
Dallas 4/1–10/31 $760 $970 $1240
w/ cover 4/1–10/31 $90 $140 $205
Atlanta 4/1–10/31 $840 $1110 $1425
w/ cover 4/1–10/31 $155 $205 $290
Los Angeles 5/1–10/31 $950 $1210 $1485
w/ cover 5/1–10/31 $85 $155 $240
Kansas City 5/1–10/31 $715 $935 $1185
w/ cover 5/1–10/31 $145 $205 $270
New York 5/1–9/30 $740 $975 $1220
w/ cover 5/1–9/30 $105 $150 $200
Chicago 5/1–9/30 $810 $1035 $1270
w/ cover 5/1–9/30 $105 $150 $195
Denver 5/1–8/31 $875 $1055 $1245
w/ cover 5/1–8/31 $70 $100 $150
Boston 5/1–8/31 $875 $1075 $1280
w/ cover 5/1–8/31 $120 $165 $235
Minneapolis 6/1–9/30 $660 $850 $1040
w/ cover 6/1–9/30 $100 $125 $190
San Francisco 6/1–8/31 $800 $950 $1110
w/ cover 6/1–8/31 $95 $165 $240
Seattle 6/1–8/31 $770 $900 $1035
w/ cover 6/1–8/31 $150 $215 $280

*Figures based on a 1,000 square foot, outdoor pool heated with an air to water heat pump with an average COP of 5.0 at $.085/kwh.

Source: https://www.energy.gov/energysaver/heat-pump-swimming-pool-heaters

 

Gas Heaters

Gas heaters remain a popular option for swimming pools because they can heat pool quickly, which can be helpful if the pool isn’t used on a regular basis. Plus, they can maintain the desired temperature regardless of the weather outside. Gas heaters burn either natural gas or propane in the heater’s combustion chamber. Pool water passes through a filter and into the heater and heat transfer’s from the combustion chamber to the pool’s water which is them returned to the pool.

Size

Gas pool heaters are rated by Btu outputs. Typical outputs range from 75,000 to 450,000 Btu. A trained pool professional can help you determine which size is best for your pool. They’ll take into account the surface area of the pool and your location’s average air temperatures as well as the difference between pool temperatures and average air temperatures. Other factors that may affect the heating load for your pool include wind exposure, humidity levels, and overnight temperatures.

Efficiency

Efficiency for a gas heater is determined by the ratio of usable output to energy input. For example, an 80% efficient heater uses $80 of useful heat for every $100 worth of fuel. Some gas pool heaters feature 89% — 95% efficiency. Most manufacturers will feature the units energy efficiency on the unit’s nameplate.

Operating Costs

The following table can help you to estimate the operating costs of a heat pump pool heater in your area:

Costs of Outdoor Pool Gas Heating by Location*

LOCATION SEASON TEMPERATURE
78° 80° 82°
Miami 1/1–12/31 $2136 $2848 $3600
w/ cover 1/1–12/31 $416 $584 $800
Phoenix 3/1–10/31 $1384 $1776 $2216
w/ cover 3/1–10/31 $96 $168 $256
Dallas 4/1–10/31 $1512 $1920 $2456
w/ cover 4/1–10/31 $184 $280 $408
Atlanta 4/1–10/31 $1704 $2248 $2880
w/ cover 4/1–10/31 $320 $424 $592
Los Angeles 5/1–10/31 $1864 $2376 $2904
w/ cover 5/1–10/31 $168 $304 $472
Kansas City 5/1–10/31 $1434 $1872 $2384
w/ cover 5/1–10/31 $288 $416 $544
New York 5/1–9/30 $1448 $1904 $2384
w/ cover 5/1–9/30 $208 $296 $400
Chicago 5/1–9/30 $1621 $2072 $2536
w/ cover 5/1–9/30 $216 $296 $384
Denver 5/1–8/31 $1757 $2120 $2498
w/ cover 5/1–8/31 $123 $168 $243
Boston 5/1–8/31 $1712 $2096 $2504
w/ cover 5/1–8/31 $232 $328 $461
Minneapolis 6/1–9/30 $1331 $1776 $2176
w/ cover 6/1–9/30 $192 $248 $384
San Francisco 6/1–8/31 $1560 $1856 $2168
w/ cover 6/1–8/31 $192 $320 $472
Seattle 6/1–8/31 $1525 $1784 $2056
w/ cover 6/1–8/31 $304 $424 $552

*Figures based on a 1,000 square-foot, outdoor pool heated with an 80% efficient natural gas heater at $.80 per therm and uncovered for 8 hours per day.

Source: https://www.energy.gov/energysaver/gas-swimming-pool-heaters

Expectations

No matter which heater option you choose, you’ll want to to have a professional pool company like American Pool handle the installation and annual maintenance. With proper care, you can expect a heat pump to last 10+ years and a gas heater to last 5+ years. If you’re in the market to replace your pool’s heater contact American Pool to schedule a consultation today!