Geothermal Heat Pumps: How We Installed Our Green Alternative to Fuel Oil Heating, Part 3

Reader Contribution by Allison Ehrman
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Geothermal Water Furnace. Photo by Allison Ehrman

This is part three of a three article series on geothermal heat pumps. Part one can be foundhereand part two can be foundhere.

Living with a geothermal system has been great so far. We only ended up using the cooling function for two days before autumn arrived in our part of the country, so I may revisit this topic again in an article next summer. But other than dealing with a torn-up yard as winter settles in, we’ve been very happy with the end results.

Our geothermal company sent a representative to our home several days after installation to teach us how to use the system. As tech-savvy as my husband and I are, I didn’t really think this was necessary, but it turns out there were a few things we still needed to learn in order to maximize the furnace’s efficiency. Anyone who buys a home with an existing geothermal heat pump or installs a new one should find an expert to demonstrate how that specific setup is meant to be used. 

At our old home, we allowed the indoor temperature during the winter to get down to 55 degrees at night and kept it at 68 during the day. But geothermal heat pumps generally come with an auxiliary “emergency” heat generator to supplement the main furnace’s heat on extremely cold days or to kick on if the system fails for some reason. Large temperature fluctuations also cause the emergency heat to run because the system is trying to play catch up, and emergency heat consumes much more energy and is therefore much more expensive than regular geothermal heat. Our thermostat automatically triggers the emergency heat if a temperature change of more than 2-4 degrees is suddenly required (we’ve since set the default to 4 degrees). So we now keep our thermostat at 70 during the day and 68 at night. We were keeping it at 72 during the day and 70 at night, but it was just too warm. The highest daily bill we’ve seen so far has been $3, but it’s only been getting down to just below freezing outside. We may adjust it to be cooler inside as winter really settles in. 

Another difference is that our system has a variable speed compressor. This means we can control how fast the cool or warm air comes out of the vents around the house. When the system was first installed, the company had the speed cranked up as high as it would go. I found the increased “whooshy” noise a little annoying and didn’t feel that we needed to be blasted by conditioned air in every room. A simple change reduced the flow back to normal. But I can see how such an option could come in handy some days. 

Although it isn’t noticeable this time of year, I know we will also enjoy not hearing the drone of an outdoor AC unit during the warm months. A geothermal pump doesn’t have an outdoor compressor and is just as silent in the summer as it is in the winter. Since the old unit was situated between our deck and patio, this will be a wonderful change. 

And the system can be set to automatically switch from heat mode to cooling mode, which is convenient for those times of the year when the weather is in transition.

Lastly, geothermal is also helping to heat our hot water. I can’t tell a difference at all, but I do feel less guilty when I stand a little longer under the shower on sleepy mornings, especially when I remember all the flood rain our well received this summer. The expert from the geothermal company did tell us that we may want to consider switching off the hot water option when outdoor temperatures get very low because using it at such times can also help trigger the emergency heat. So we’ll be keeping an eye on that as well. Luckily, our smart thermostat makes monitoring and controlling everything quite simple. 

Water Furnace thermostat. Photo by Allison Ehrman

All in all, I highly recommend geothermal heat pumps as a green alternative, especially if you find yourself in the market for a new system. Current rebate incentives make the price comparable to traditional systems, and the cost and energy savings can’t be beat. As for the comfort they provide, I really don’t mind not having to wear three layers of clothes in my home at night while still using less energy for heat each month. 

If you live in Northern Maryland and are looking for a reliable geothermal company, I recommend the services of Ground Loop, Inc.

Allison Ehrman works in the corporate world, but her heart and soul reside in her Northern Maryland country home, where she and her husband grow and preserve herbs and vegetables, prepare exotic dishes from locally-sourced foods and craft natural body care products. You can read more of her Mother Earth News articles here.


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