A couple years ago I put an article together talking about Geothermal Heating and Cooling Systems. My friend and her husband were installing a Geothermal Water Based Furnace in their home. A costly project that was going to take about a month to complete but in the end the money and time spent were going to be well worth it. Three years later they love their system and are almost at the break even point when it comes to the money they save on their electricity, gas bill and what they spent on their system.
My husband and I have a very open home with lots of hard to heat and cool elements in the house. One of them being the lack of heat on the main floor and abundance of heat on the second floor due to the issue of the second floor being open to the main level. The basement has always been comfortable and in the winter we would put the baseboard heaters on really low just to take the chill out of the air. Our heat pump system was installed in 2006 and the previous owners chose to take the cheap route when they chose the system. The last few winters we have been worried that the heat pump would quit on us when we had a overly chilly day. On certain days that I was home I would start a fire in the fireplace just to take a little pressure off the heat pump.
We have finally bitten the bullet and decided to go with a Geothermal heat pump system. We have plenty of yard for the wells to be drilled and it turns out they only need two 6-inch wells for the loops to be placed into the earth. So even if we didn’t have a great big yard there still would of been plenty of room. In the end there will only be one unit on the inside of the house and our outside heat pump unit will be removed. When we started looking at systems we found there are two (2) different options to choose from. The first system is your basic Water furnace system and the other is what they call a DX or direct exchange system. Here are the differences:
A WaterFurnace geothermal heat pump uses the ground loop to extract heat from the ground when heating your home. The system then takes the heat and distributes it to the conventional duct system. This same heat can be used to heat the water in your hot water heater also saving energy and dollars. The ground loop system is made from Earth Loop that pumps a water-based solution through a polyethylene pipe.
When cooling your home the process is reversed. The heat from the air in your home is placed either back into the ground or put towards your hot water heater needs.
In the Direct Exchange system you have the same basic concept but with one less step and different piping. Refrigerant is sent through copper piping where the ground heat moves across the copper piping without the need to use a water pump to circulate water through plastic ground loops. One issue that the system needs to overcome is the copper becoming compromised in the ground and one way to do this is to add an anode. The anode acts to protect the copper by sacrificing itself to corrosion thus protecting the copper piping. One benefit is the loop system does not have to be as large as a water based system thus can be placed in areas where space is limited. Another advantage is the one step exchange of heat in the system versus the two steps required in a water based system.
In the end, the husband and I chose the WaterFurnace for two reasons. The copper piping and refrigerant used in the system worried us when it came time to replace the pipes and the potential environmental repercussions if a pipe were to burst. Also the Direct Exchange system has only been in existence for about 10 years whereas the water-based system has been around for more than 30 years. The people that can work on and maintain the water-based system are in the hundreds compared to the select few that work on Direct Exchange systems in Northern Virginia.
The whole process is going to take about a month to complete but with only about 6 hours without heat. If the day is bitterly cold the contractors over at North American Geothermal will have space heaters for us to take away the chill while they complete the install.
The first step towards completing the project was determining the tonnage of the unit needed for our home. A Manual J was performed, Room-by-Room Load Calculations provided the heating and cooling loads for each individual room within the home. This information is critical when determining the individual duct sizes, overall layout of the duct system, and unit size needed for the home. In our case we are potentially adding on to our home increasing the square footage thus needing a 4-Ton unit versus a 3-Ton for the existing house. We decided to go with the 3-Ton unit and if we do add on in the future we will be adding a splitter system to heat and cool that larger addition.
Once this was determined, North American Geothermal has started the process of acquiring County permits to drill the well holes and ordering the equipment needed for installation. In about two weeks they will start drilling holes.
Stay Tuned to watch the installation of our new geothermal system….