One of my readers (Brian) asked the following question on the article, “Icynene-the Ultimate Barrier to High Energy Bills”:
“You mentioned geothermal in the Northeast and I am curious to see how it works in this area. I am building a house in Mass and interested in geothermal, solar, and Icynene. I know this is a discussion on Icynene, but I have some questions about Geothermal. How much did it cost to install? How big is your house? Did you run into any issues (IE Blasting ledge) and last but certainly not least, how long have you had it and have you had any maintenance issues?”
I wanted to check with my new service company (Perfection Contracting in NJ) before I wrote this post, but Brian asked in another later post, if I could respond to him as quickly as I can since he is breaking ground this week. So, on Sunday evening I am trying to answer his questions without the benefit of checking my answers with my geothermal company. If any installers have anything to add, please do since I am not an installer, but simply a homeowner who drove my installers crazy asking questions.
First, before we go any further, watch this video which explains how a geothermal system is installed and how it works:
Brian-My geothermal system was installed about 3 years ago. We used Water Furnace equipment to heat and cool the house, for radiant heating in the bathrooms, and for hot water through a separate geothermal hot water system.In addition a loop was set up so in the summer, hot water would be created for free because the heat of the geothermal units would “dump” into the hot water tanks.
Since we have installed our system, Water Furnace now sells more efficient units than the ones that I own. So, I can’t tell you the cost because it would not be accurate. Another house in town has geothermal, but his whole house is radiant and he uses his radiant boilers to heat his pool in the summer.
If anyone is considering using their geothermal leftover heat to heat their pool in the summer make sure the water does not circulate back into the house; otherwise you could have your pool in your basement if something goes wrong.
A heat exchanger is installed in a pool house out by the pool so the pool water is heated outside rather than in your house.I need to check on the right words.As I mentioned earlier, in my haste to answer Brian, I can’t verify if this is the correct terminology without the help of my service company.
Another smart idea this other homeowner implemented was to install a back-up heating system for the geothermal. Up north, a geothermal system does not do as well when the temperature dips to 20 degrees depending on your insulation. In my case it is around ten degrees because of my Icynene insulation (open cell foam). I would imagine the better the insulation, the less likely the geothermal system would have as much trouble. When the system is having a hard time keeping up with its demands, it will go to back-up heat which is full electricity. This is an expensive stage. It is one watt to one watt electricity at that point versus 1/3 watt to 1 watt electricity other times.
I would recommend in your area to have an efficient gas or solar system that would take over before the system goes into its back-up situation or if a geothermal unit or loop fails.
Make the Units More Efficient
Since you are just breaking ground, go back to your architect and discuss if you can use a nice size 2nd floor room closet to put the 2nd floor units in. The alternative is you must put the unit in a closet in the attic which is is insulated well, including the door. (Basically, they open up part of the geothermal unit so it heats and cools itself in the closet.)
These closets need to be designed so that the installer does not put the units where it is impossible to build these closets, like too close to the side of the attic near the soffits.
Your architect and installer will need to meet so your builder knows where to build the closets. Build them as you are building the house, not after the fact. The units are so much more efficient when they are in a conditioned space. I still have to build closets around my system in the attic since I was told after the fact by another installer.
In addition, I am going to spray icynene on the ducts in the attic because most installer only put R-6 on the ducts which was energy star’s requirement.The more insulated around those ducts, the better.
If I had my druthers then I would have put all my ducts, geo, etc in a conditioned space. (i.e. ducts in my first floor ceiling and units in 1st or 2nd floor closets.) I was told and I have not verified this, but energy star now wants your ducts in conditioned space. It makes perfect sense.Everything in conditioned space has to do better.
All Units in the Basement?
Another issue is since the units are in the attic; the water inside the geothermal units is pumped up to the attic so sometimes it sounds as if the wall is making a low rumbling noise.This may be due to how the pipe was attached to the framing, and was it insulated properly to reduce this noise.
Note, that only one of my units makes this noise so I suspect it was an insulation issue for that particular pipe.
My new service company told me they like all of the units in the basement and only the condensers and ducts upstairs. This is called a split system. I am not sure if you need to build closets in this situation. This split system eliminates the noise and possible water issues in the attic. Brian, it may be something for you to discuss with your installer. All units in the basement or not.
Make Sure the Units Are Set Properly
Also, when the installation is done and as dumb as this may sound, make sure your geothermal systems are set for whatever system you have. There are open and closed systems. Mine was set for a well when I in fact have a closed system.
In addition, make sure the air flow in the house is balanced the way you like it. For example, you may want more air in rooms that are used versus not used.All my units were not set properly.I think this had to do with the head of the Company passing away.I had a lot of issues because of his untimely death. I think my situation is unusual.None of these issues were due to the Water Furnace equipment but rather the installer.
As for drilling, if I remember, I think my wells are about 300-350 feet down. I am on a hill so everyone is different.In my area, the excavation of a horizontal loop may have been more expensive than a vertical loop.
The other house that I spoke about added a few wells in case he needed them later for future expansion or something happened to one of the wells.I thought this was smart idea if you may want to add to your house or add an additional structure.
What Would I Have Done Differently?
What would I have done differently? I would have the installers set up the radiant hot water on it own geothermal boiler system and not tied it to a geothermal furnace unit.Now, if the radiant is calling for heat, the furnace has to wait to heat part of the house.It does not happen often because my first floor does not call for heat that much. I also would have installed the system as a split system and put closets in from the beginning.
Make sure you have surge protectors on the units. They are electrical. An electrical surge could damage the units. We have many outages where I live and it caused a problem with one of the units.
As for maintenance, I have dampers on my second floor since a couple of the units heat some rooms and others heat other rooms.Sometimes, the dampers get stuck and the units will not shut off. (Dampers allow for one unit to heat several rooms by shutting off the heat to some rooms when they reach temperature and keeping others open until they reach desired temperature.) The damper problem has only happened with the heat.
I am not sure why this is happening, but my second damper issue is happening right now.Is this because it is up in my attic and it is cold?I don’t know but my service installer is coming tomorrow.I have already had one damper replaced.
When they set up which units heat and cool which spaces, really think about is this going to work.To give you an example, I have one bedroom that is tied to my laundry room.Since this bedroom faces south, the heat never goes on. The laundry room on the other hand is large enough that it probably should have its own duct damper. The heat never goes on in the laundry room.I am going to have to revisit this issue this winter.(Last winter we put in another duct because there was not enough air going into that room.)
I have a ten year warranty on the units but Water Furnace only reimburses for some of the labor cost and parts. In addition, you need to have the units checked twice a year like your normal heat and air conditioning system. Ask what that is going to cost in advance, so you know. I would also suggest buying 2 sets of filters for each unit.You have to wash them sometimes.As they dry, you can install the other one.
I keep my downstairs and upstairs at 68 during the winter and during the summer my downstairs is 76-78 and upstairs is at 74-76.I have an energy star house so I had to have all the duct seams mastic (which I would encourage anyways). Anywhere you could “swipe” a credit card through two pieces of wood, I had to use silicone to close the gaps, and I had to pass their blower door test.All 3 floors have Icynene (basement through 2nd) in the exterior walls.
Geothermal savings are more in the summer than the winter but don’t believe the 70 percent figure you hear unless you live where it is warmer. I think I am more like 50-60 percent in the summer and 40-50 percent in the winter but I don’t know. It is hard to know because I only have an electric bill which includes all my lights (which is pretty efficient lighting) as well as my geothermal. I compare myself to houses that are new construction using gas.Perhaps I am doing better than I think.
I was told that my savings would be about 20-30 percent in the winter and 70 percent in the summer.These numbers may not take in account the Icynene.I know that has impact. Also, don’t forget to check out what your state’s incentives and rebates are.
Water Furnace has a nice savings calculator for you to use to see what your savings would be if you installed a geothermal system versus a conventional heating and cooling system. Before you enter in your information, make sure you know your per kilowatt cost for electricity and cost for natural gas.
In addition to the savings, I like the fact that there are no condensers outside like you see in conventional air conditioning systems. The system is very quiet except that one wall that rumbles a little.
Heat Recovery Units Needed
In addition, if your house is vety tight you need to install an energy recovery system to circulate air in your house.I have a HEPA/heat recovery system in my attic by Broan.(These units should also be in the closet with the geothermal units.) See my article, “Is Your House Suffering from Bad Breath?”
Water Furnace also makes an energy recovery system . In addition , I have 2 humidifiers which put moisture in the airin the winter.They are made by Aprilaire and are the wrong units for the geothermal units. They were put in by the Company after the boss passed away.I have retrofitted them to work. Again, Water Furnace makes their own humidifiers to work with the system.
Since the geothermal system does not heat water as hot as boilers, they need humidifiers that can heat their own water. There are specific humidifiers that are made to be used for geothermal systems.
Whoever you use, make sure you get a couple of references. Try to get references from people who have had their geothermal systems for at least a year or so. You want to hear from someone who already went through both a heating and cooling season.
In addition, see if you can get a reference from someone who has the same size house that you are building. Ask them for a copy of the electric bill.It should show you their electrical cost for the whole year.
As for solar, I looked into that too.It was too expensive for the savings that I would receive.This is totally off the top of my head, but I remember that 3 years ago, the cost of the system was about $60,000 or so and NJ gave back 60% I think.The problem was a 10k system which was only going to produce 13,500 kilowatts.
At the time it was 9.8 cents per kilowatt in NJ, my savings for the year would only be $1323.The payback (15-18 years) would be horrible based on the cost of the solar panels. I am waiting for more efficient and less costly solar panels. In addition, NJ has changed its program.
You bet I would in a heart beat. I love this system despite some of the installer issues. It is quiet, efficient, saves me money, and helps the Earth. What else can I ask for?
Brian, I hope I was able to answer your questions. Please let me know what you decide.If you have any further questions, post again.