Geothermal heat pump: first winter results

[truckdiagnostics]

fordmantpw, I have horizontal loop hence the 8 instead of 6. More cost effective and if you have the space. I just paid the farmer to come out for the day with his excavator. The big reason for the 6 instead of the 8 is we would have had to bank it, for safety in the trench. Up until say winter before last has not been issue. I have also heard bad things about the slinkies. We laid out our own loop and make up own manifolds. Also, based on my understanding on how the 7 series it is a nice unit..... Both our units do not have staged compressor, not available back then. Also believe the 7 is a whole bunch quieter. The unit in the house is under the bed room and when it is running has a nasty hum. Putting it there not one of my smarter ideas. I have heard other complaints on the noise/hum. So consider that when locating.

 

[jk96]

Nobody ever says you have too much capacity!

A word of caution. We had geo installed and actually did have problems with too much capacity. Basically due to how tight the house is along with spray foam insulation our run times were averaging anywhere from 8-15 minutes even when the temp was in the teens. Multiple zones also compounded the problem. This led to inefficient run times in the winter and high humidity in the summer due to short cycling.

Jeremy

 

[fordmantpw]

fordmantpw, I have horizontal loop hence the 8 instead of 6. More cost effective and if you have the space. I just paid the farmer to come out for the day with his excavator. The big reason for the 6 instead of the 8 is we would have had to bank it, for safety in the trench. Up until say winter before last has not been issue. I have also heard bad things about the slinkies. We laid out our own loop and make up own manifolds. Also, based on my understanding on how the 7 series it is a nice unit..... Both our units do not have staged compressor, not available back then. Also believe the 7 is a whole bunch quieter. The unit in the house is under the bed room and when it is running has a nasty hum. Putting it there not one of my smarter ideas. I have heard other complaints on the noise/hum. So consider that when locating.

I figured you had horizontal, just joking on the tape measure comment.

For us, they said the cost to go horizontal was only about $1k less than vertical. Then you have to deal with settling, etc., and it just wasn't worth it. I'm sure I could have done some of that myself to save more $$, but frankly, I just didn't have the time with everything else going on.

Our 7 Series is extremely quiet. Actually, we hear the water pump pumping the water through the loops over the furnace itself. And with the variable speed compressor and fan, that just aids in the quietness.

 

[fordmantpw]

A word of caution. We had geo installed and actually did have problems with too much capacity. Basically due to how tight the house is along with spray foam insulation our run times were averaging anywhere from 8-15 minutes even when the temp was in the teens. Multiple zones also compounded the problem. This led to inefficient run times in the winter and high humidity in the summer due to short cycling.

Jeremy

That's a very good point, but based more on the unit size than loop size. My parents have a geo unit in their house and they actually have to 'dump' a bunch of air in the basement to help with the issue. The joke is that you can hang meat in their basement in the summer! They were right on the fringe on unit size and decided to go up a size.

A note on the efficiency side. On the very coldest days, our unit would average around 1500 watts +/- for the day. Think about that for a minute. Many hair dryers use 1500 watts. A ceramic space heater uses 1500 watts on high. We were heating our entire house for the cost of running a hair dryer or space heater.

 

[dodge man]

Yes, mine also uses less than 2000 watts when it running.

One problem with ours is I like it cold at night when I sleep. I usually only turn it down 1 or 2 degrees at night but it would be better if I didn't change the temp at all.

 

[MacLawn]

On the unit sizing, going too big can cause clamy, damp feeling in summer. Any ac unit needs to run at a bit warmer and run a bit longer to properly remove humidity. Bigger is not better here.

My man said if we drill instead of dig trenches, we would need 3 200' holes, but cost would be $5,000 more to drill! I have space to trench, but dagnabbit, I just hate to have all that Georgia red clay dug up like again at me place! That stuff will stick to ye hide!

 

[fordmantpw]

Do you know how close the water is to the surface at your place? When they put ours in, they said they hit water early, which helps drastically with performance of the system and make it more efficient. Now, that won't make up the $5k difference, but it will make up some over the long haul. I'm with you on digging up the yard to trench it. Man, it just never seems right after that. We've got a lot of clay here too, but we've also got tons of rocks. The rocks come to the surface and you are picking them up for years, they destroy lawnmower blades, bust windows, etc. $5k seems like a lot, but when you factor everything else in, I would say it gets cut in half. You have to work it up, seed it, straw it, water it, overseed it the next year, yada yada yada.

 

[Redneck in training]

Find somebody doing directional drilling. The guy who installed ours geo had directional drilling machine. They could install loops from one relatively small hole. I can't recall the brand of the machine. It used a pipe made of mild steel that was passed through several pulleys to bend is in such arc that it would emerge from ground in certain distance. On the front of the pipe was hydraulic motor driving the drilling head. The motor was powered by a drilling polymer that lubricated the bore and provided a thermal contact when the loop pipe was pulled in the bore by retracting drill. They could install loops under the buildings or trees.

 

[fordmantpw]

Find somebody doing directional drilling. The guy who installed ours geo had directional drilling machine. They could install loops from one relatively small hole. I can't recall the brand of the machine. It used a pipe made of mild steel that was passed through several pulleys to bend is in such arc that it would emerge from ground in certain distance. On the front of the pipe was hydraulic motor driving the drilling head. The motor was powered by a drilling polymer that lubricated the bore and provided a thermal contact when the loop pipe was pulled in the bore by retracting drill. They could install loops under the buildings or trees.

That's awesome! Would love to see one of them machines work.

 

[truckdiagnostics]

i believe when he said more is better is he may have been referring to loop size, if that is the case I would agree to a certain extent. I put the trench in when the foundation was going in so everything already dug up. Feel for you on the clay, we have it here but they put rocks in ours and sometimes really big boulders, our loop makes a curve because of one.
Maclawn, is he using your old heat pump air handler our is he installing a new one?