Feb 4 2015
Heat Pumps for Martin County Homes
For the Treasure Coast in general and Martin County in particular, heat pumps are an excellent energy-efficient alternative to furnaces and air conditioners. Because Martin County seldom sees extended periods of sub-freezing temperatures, its residents can take advantage of heat pump technology.
Similar to a refrigerator, a heat pump uses electricity to move heat from a cool space into warm space. During the heating season, heat pumps move heat from the cool outdoors into your warm house; during the cooling season, heat pumps move heat from your cool house into the warmer outdoors.
Because they move heat rather than generate heat, heat pumps can provide up to four times the amount of energy they consume. If you heat with electricity, a heat pump can trim usage by as much as 40 percent. High efficiency heat pumps with variable speed air handlers can also dehumidify better than standard single capacity units, resulting in less energy usage and more cooling comfort in summer.
Right Sizing for Heating and Cooling Equipment.
Getting the right size heat pump for your home is a very important process. It makes as much difference to the comfort of your home and the durability of the system as getting the right heat pump model or finding the electrician for the job.
Fixed-capacity direct exchange (DX) space conditioning systems, whether heat pumps or A/C systems, cycle on and off to meet space cooling loads. During system start up, there is a several-minute period during which the cooling coil becomes progressively colder. Sensible capacity recovers to 90% in about one minute while latent capacity takes longer to recover. Therefore, during the first several minutes of each ON cycle, both capacity and efficiency are diminished. During the OFF period, sensible and latent cooling energy stored in the air handler unit (AHU) and ductwork is lost to ambient surroundings.
The number of ON/OFF cycles per day and the proportion of the time that the system is OFF then affects system efficiency. Right-sizing reduces the number of cycles. Over-sizing increases the number of cycles per day and shortens the length of each ON cycle. Therefore, the percentage of the time that the system is operating at full capacity and efficiency is decreased. While a FC system may cycle on and off 50-75 times per day, a VC system may cycle on and off only 10-15 times per day.
Oversizing Variable-Capacity Heat Pumps.
Research performed in a South Florida lab house found that right-sizing fixed capacity (FC) heat pumps produces seasonal and peak energy savings while over-sizing variable-capacity (VC) heat pumps produces seasonal and peak energy savings, for both cooling and heating periods. These results support current state codes and primary standards such as Air Conditioning Contractors of America (ACCA) Manual S to right-size fixed capacity systems, but challenges them to allow over-sizing variable-capacity systems. ACCA currently allows up to 15% over-sizing for fixed and variable-capacity units. They have recently begun a review process to allow variable capacity systems to be over-sized by no more than 30%, however there is evidence presented that supports considering a much higher limit of perhaps 100%.
Apr 9 2015
Solar Power Installation Timing
Timing Your Solar Power Installation.
With spring officially upon us and Florida’s long, sunny, summer days approaching, you may be considering a solar system installation now to let the sun be your utility provider. Solar power generation is part of the solution to lower electrical generation costs. Solar power generates clean energy and helps to reduce your individual carbon footprint as well.
Residential solar power generation is no longer more expensive than traditional fossil fuels. Indeed, it is cheaper. So, a home solar system can save money month after month while providing a better future for the planet and generations to come. That said, the real issue is not whether you should or should not install a solar power system on your home, but when.
Major home solar installation companies, such as Sunrun, claim that the timing for you to install a solar system couldn’t be better. They point out that through 2016, you can take advantage of a federal tax credit that lets you write off up to 30% of the cost of buying and installing a solar system. They also suggest that there are also many programs available that allow homeowners to go solar with $0 down.
But, as always, the devil is in the details. According to Sunrun, On average the total cost of solar installation can be between $15,000 to $29,000 for average sized systems sized between 4kW and 8kW. The go solar with $0 down contracts typically let you pay for the electricity you use at a 20% discount from your current utility rate being charged by FP&L.
For the average Florida homeowner, it would take a lot of years to justify the installation, even if electrical rate rise. But, what if utility rates fall? Homeowners locked into a long term contract such as described above would pay dearly for their bleeding edge technology.
Future Solar Power Installation Costs.
And, that scenario is highly likely. According to Giles Parkinson, founding editor of RenewEconomy.com.au, “Solar Costs Will Fall Another 40% In 2 Years.” After reading that article and others, I am inclined to believe that now is not the perfect time to install a solar power system on a home in Florida. The time will come, but it is not now.
Would you like a complimentary…no obligation …project consultation? Please feel free to call for more details. Mobile: 772-263-2333.
By Glenn_G • Solar Power • • Tags: Residential solar power