For many years now, geothermal systems have kept the promise of saving significant amounts of energy. The biggest obstacle has traditionally been the upfront cost. Let’s look at five features that may help you in the all-important decision making process.
#1 – Works “magically” like a fridge
How many people can actually explain how their refrigerator removes heat from its interior and transfers it out of the box? Or, for that matter, how many people can explain how a combustion engine works? Regardless of this lack of comprehension, few are those who hesitate when purchasing a $30,000 automobile but many do when shown the geothermal sticker price of $30K!
A geothermal heat pump moves heat from the ground to your home (or vice versa). It uses an underground piping system called “closed loop” which is filled with a water/antifreeze liquid to transfer the heat. The geothermal heat pump is reversible & thus acts as both furnace and air conditioner.
During the heating season, the liquid pulls heat from the ground and delivers it to the geothermal unit and then to refrigerant coils, where the heat is distributed through a forced-air or hydronic system. During the cooling season, the process is reversed. The pump removes heat from your house and transfers it to the earth. Many units can also provide domestic hot water.
A geothermal heat pump is much more efficient than conventional heating systems because it doesn’t burn fuel to create heat; it simply moves it from one place to another. And because underground temperatures remain at a relatively constant 10°C year round, the system requires a lot less energy to heat or cool your home than conventional AC systems or air-source heat pumps, which use outside air as a transfer medium.
#2 – The “perceived” upfront cost
Installing a geothermal system is perceived to be expensive. The upfront cost is between $10,000 to $30,000 depending on many factors such as soil conditions, lot size, system configuration, site accessibility and the amount of digging and drilling required. However, consumers should only consider the upfront cost of the loop in their financial analysis, as the total cost of the system must be offset by the equivalent cost of the alternate system.
We are often asked about payback: in general, if one third of the upfront cost maximum is attributed to the loop installation, the actual payback is relatively short. We use life cycle costing analysis for all major renewable energy projects but it is not used very often for residential projects. To compare alternatives, the actual net value of a 20 to 30-year life cycle cost should be calculated for all geothermal projects.
It takes homework and professional estimates to figure whether a geothermal system makes financial sense in your situation.
#3 – Geothermal has true & proven benefits
- Proven lowest operating costs
A geothermal heat pump system saves up to 70 percent in heating costs and 50 percent in cooling over conventional heating and cooling systems.
- Uses clean, renewable solar energy
With a geothermal heat pump, there’s zero emissions of carbon dioxide, carbon monoxide or other greenhouse gases. Nor are there any combustion-related safety or air quality issues inside the house. The system uses electricity, which may be generated using fossil fuels.
- Can be installed in both new construction and retrofit situations
Retrofits may require ductwork modifications.
- Much quieter than other cooling systems
There’s no noisy outdoor compressor or fan. The indoor unit is generally as loud as a refrigerator.
- Low maintenance and long-lived
The indoor components typically last about 25 years (compared to 15 or less for a furnace or conventional AC unit) and over 50 years for the ground loop. The system has fewer moving parts and is protected from outdoor elements, so it requires minimal maintenance.
#4 – There are downsides, besides the cost
- Most geo projects are not Do It Yourself
Sizing, design and installation require a qualified (trained) geothermal expert, some homeowners can contribute to the excavation of horizontal systems but most projects are NOT DIY.
- Technology is unfamiliar to the masses
Qualified geothermal dealers are not as abundant as conventional system dealers.
- Loop installation is “groundbreaking” in many ways
Some configurations may not be possible on some lots. Drilling vertical or trenching horizontal loops using heavy equipment will be disruptive to your landscaping.
#5 – The added cost is the loop
Closed-loop systems are the most common. Less common, the open-loop system circulates surface water or water from a well, through the system and returns it to the ground through a discharge pipe.
The best system, loop length and design for a particular home depends on a variety of factors such as climate, soil conditions, available land, required heating and cooling load and local installation costs at the site.
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