Geothermal Heating and Cooling

[toconnor]

That is awesome Kraig. Variable speed is the way to go. We have done a few variable speed Trane systems and they are outstanding with a great warranty. I'm sure you will be happy with the new system. I like to burn wood too but it gets expensive here with wood going for close to $250-$300/cord.
I put a new Trane heat pump in my house about 4 years ago and I'm thinking about pulling it out and putting in a variable speed Trane unit. I'm running into an issue with high humidity inside the house because I spray foamed my attic after the install and it took a bunch of the heat load off of my house and now my unit is over sized. IIRC the new variable speed units can go down to 25% of rated capacity and still keep the evaporator just above freezing to ring out as much moisture as possible. Technology......crazy isn't it!

 

[kmcconaughey]

Todd, is that $250-$300/cord for split seasoned firewood? The last two semi loads I bought were around $100/cord but that's for 8' logs. I still have to cut, split and stack (season) it before it's ready to burn.

I have to work this morning for a few hours. I'll miss out on some installation action as they should be back this morning to fill the underground loops with a water methanol mix and purge any air. Hopefully the electrician shows up today to get the electrical hooked up.

Nothing real exciting for photos from last Friday's progress. Just a shot of the old furnace partially disassembled for removal and the new geo unit in place but not yet connected up. Note the water heater in the background, I installed that a little under three years ago and now it'll be replaced with a new one that is part of the geo setup. It'll look the same as both are made by Rheem (Marathon). The new one has some additional special ports in it where the geo unit plumbs into it. I need to find a buyer for my less than three year old, 50 gallon electric water heater...

 

[toconnor]

Looking good Kraig. Yes, $250-$300/cord here that is split and maybe seasoned if you're lucky and delivered. It's about $200-$250 if I pick it up. Most times you will not get a true cord of wood.

 

[kmcconaughey]

Yesterday they got the ground loops connected to the the pump, filled with water and purged the air. Then they added in the anti freeze, which in this case is methanol, and circulated that and got it up to pressure and disconnected their pump cart. Waiting on the electrician, he has another job to finish up. Also the duct work is yet to be connected up. Once the electrical connections are done and the ducting is connected the water heater can be swapped out.

 

[kmcconaughey]

The Geo install was completed yesterday. The system has been up and running providing hot water for a week now. The ducting sub-contractor has been swamped with work. He was able to get the last bit of ducting for the cold air return installed yesterday morning. He installed the supply plenum and a portion of the cold air return last week so it was usable if needed for heating or cooling. I did test out the cooling one day last week when it got above 80. It's very quiet. The high today is only supposed to get to about 50 so we'll be able to test the heating a little. This afternoon the installer will be doing some performance tests and tweaking also will give me a quick training on using some of the features. It has a smart thermostat so I can log in with a PC or smart phone to check stuff and/or change settings.

 

[wshytle]

Kraig-

Have you figured out how long it will take for the unit to pay for itself? I'm sure it was an expensive install. I think you mentioned something about some solar assistance as well.

Just curious.

.

 

[kmcconaughey]

Wayne, because I'm switching from primarily wood heat the current cost to heat is a bit harder to calculate. The calculations from the installer show it as somewhere between 7 to 10 years. I'll have a better idea after I get a few electric bills to compare. I'm more excited about getting back a bunch of spare time now that I wont have to spend it doing all the stuff I have to do when heating with wood (well after I cut up and split the half semi load of logs I have left) So I might even be able to finish the refurb of my #1 model 125.

Or at least find some time to do some MUCH needed Cub maintenance. The cost after rebates and tax credits should be just under $21,000. But that gets me all new heating, cooling and domestic hot water heating.

 

[toconnor]

Kraig, that looks like a very nice install. Around here, you won't see companies use canvas connectors or putting a cross break on any metal. Keep us posted on it works.

 

[Oak]

Kraig, just checking on how this system has been working for you now that it has been in for 2 1/2 years? Any issues, wish I woulda done and how does the power bill compare to the old system?

 

[kmcconaughey]

Oak, there was one issue early on that was covered under warranty, where a valve stuck that switches between space heating and water heating, the installer figured it was something that was inside during manufacturing that got caught in the valve. This is an internal valve that is a closed loop with the refrigerant. Once that was fixed it has been flawless. I expected it to cost more to run than my wood furnace and my electric bill has gone up some but it's so worth it. It is cheaper to run in cooling mode than the old air conditioner so my summer electric bill has gone down slightly, but I run it much more than I did the old air conditioner. It's also much quieter than the old air conditioner and the wood furnace. On the coldest winter days when it's well below zero it has had no trouble keeping the indoor temperature at a constant 70 degrees. I have only had a few fires in the wood furnace since having it installed. I should probably fire that up just to run it some. No regrets, I'm very happy with the system.

 

[Greg Riutzel]

Cool project. We've considered geothermal for years but with wood heat for over 30 years it's kinda hard to change plus sticker shock. You'll be our "test pony"

issue with high humidity inside the house because I spray foamed my attic

Todd, you may be having a ping pong affect going on in the attic; especially now that it's so tight the water has no where to go. It'll rot the roof's underlayment if the root cause isn't fixed. Look up ping pong humidity and it's affect on roofing.

 

[Oak]

Greg, that is interesting, thanks for the heads up. I have 2 temperature/humidity data loggers in the truck that I'm going to put in the attic to see what mine is doing. Not really an issue this time of year but it will tell me if it is swinging.

 

[jmacdonald]

Kraig just finished reading the entire post. It's very interesting. I wonder if geothermal is only for hot air heating systems as I have an oil fired boiler for hot water baseboard ?

 

[kmcconaughey]

James, my sister has a geothermal heating system with in floor heating, via water filled loops in the floor, she has electric powered water heaters as backup.

EDIT: I remember now, she has electric water heaters that are for backup to the geothermal system. I have updated the above info.

One thing I should mention is choose your installer very carefully. I initially had three companies come out to give me quotes. I was not impressed with two of them and the third guy was very busy and was not able to get back to me. (He had recently purchased a second HVAC company and was busy fixing all the messed up installs that it had done.) I kind of gave up on going with geothermal and then I learned of the guy who's company I went with, Jerry Sand at Innovative Energy. My sister and her husband had their system installed back in the mid 1980's and had a bunch of issues with it. They have it sorted out now with a different installer who is also good. I don't recall his name/company at the moment but it's the guy that was too busy to get to my install that I mention above.

 

[Rgausman]

Hi Kraig, Just read the whole thread.

Your installer did a good job. Guessing looking at your pictures, you have acidic water and reason to swap out the Marthon hot water tank. Looks like they treated your water while filling the ground loop.

You say your electric bill went up... What was your winter bills if you only used electric? Geo is a great option for northern part of the country if you are paying for your fuel source. As you realized, there is no such thing as free heating.

I am also a geo/cub owner. Back in fall 2017, I took a five day IGSHPA Installer certification course sponsored by a Hydron Module dealer. Bought a 4-ton unit and buried 2000' of 3/4" HDPE pipe in four 100' trenches in slinky horizontal configuration. I went with the non-pressurized flow pump center. My total DIY cost was about $16K not including my labor ( ;>). Also installed a web-base monitoring system and amazing how everything works as designed. Web Energy Logger# 58

My only problem has been the Grundfos 26-99 circulator pumps last few years. I filled with 'clear' well water and 25% methanol. I believe problem is the water chemistry which is causing crud build up in the 'wet rotor' pump. I am working on this issue now. My total DIY cost was about $16K not including my labor ( ;>).

#1 Question always asked. "How much money are you are saving". It is a loaded question. I looked at as a 20-30 year expense. Most air source heat pumps are usually good for 10-15 years.

#2 Question asked by someone who is thinking to do it themself is "How many feet of pipe do I need to bury?

Kraig - Attach a few photos, you think your yard was a mess... This was a little more than cub could handle

Bob G.
Madison, VA

 

[kmcconaughey]

Bob, Wow! I'm glad my installer used the horizontal drilling method. How deep are those trenches?

The "old" Marathon tank was replaced because the new Marathon tank came with the geothermal system and has a different electronics and piping configuration. Nothing was wrong with the old Marathon, I sold it on Craigslist and got most of my original purchase price out of it. I had just installed it a little over two years prior because the 38+ year old Montgomery Wards water heater was starting to leak a wee bit. Which was partially due to a new well pump which had better water pressure. Domino effect.

I'm not sure how much my house cost to heat with the old forced air electric furnace because I never let it heat the house by itself. I always ran the wood furnace when I was home. It did run when I was at work or away for a weekend. I was never away for an entire month during the heating season. Entire house was/is electric. Electric backup water heater, electric range, electric cloths drier, electric blower on the wood furnace, electric backup heat in the geothermal unit. Previously we were on off peak with the electric furnace and water heater so that used to be at a lower rate. I'll have to check to be sure, but I recall that the electric bills are now typically in the $95-$150 range for summer and top out around $230 for one of the coldest winter month average winter bills are now around $180. I believe it used to top out in the $150 range when using the wood furnace for heat. EDIT: I corrected the monthly cost after looking at some of the actual bills.

I knew my electric bill would go up so I have no issue with the higher electric bill. Plus I no longer have to buy firewood, cut it, split it, stack it, buy tarps to cover it, haul it, clean out ashes, clean the chimney, buy all that gas and oil for the chain saw and log splitter, run up and down steps to feed the wood furnace, wake up to a house that's at 59°F (that's where I used to have the electric furnace set) and on and on. I should probably start a work out program to stay in shape, I'm not getting as much excersize as I used to.

 

[Greg Riutzel]

I should probably start a work out program to stay in shape,

That's funny. They say wood heats you twice We have log loads delivered and I don't need gym membership; however approaching 70 the days just don't last as long. Feeding the stove is sometimes a pain but I keep thinking I'm not so dependent on the grid either. A wall stat is starting to look sweet nonetheless.

 

[Greg Riutzel]

That is awesome Kraig. Variable speed is the way to go. We have done a few variable speed Trane systems and they are outstanding with a great warranty. I'm sure you will be happy with the new system. I like to burn wood too but it gets expensive here with wood going for close to $250-$300/cord.
I put a new Trane heat pump in my house about 4 years ago and I'm thinking about pulling it out and putting in a variable speed Trane unit. I'm running into an issue with high humidity inside the house because I spray foamed my attic after the install and it took a bunch of the heat load off of my house and now my unit is over sized. IIRC the new variable speed units can go down to 25% of rated capacity and still keep the evaporator just above freezing to ring out as much moisture as possible. Technology......crazy isn't it!

Maybe a multi/2 speed motor to get by? If you know or can find the sensible heat capacity of your unit, maybe you can play with fan speed for latent to sensible heat ratio to wring some water out in the meantime.

 

[John DeBree]

Interesting thread! We looked into geothermal, but it would have never paid off. Our total costs for HVAC run about $300 a year. Yes, I said year. Our DIY house is ICF, so it's ridiculously efficient. We use a small mini-split for all of our HVAC, because they don't make central systems small enough. Our house is 1400 sq ft on the main floor, with a same-size finished basement, and our cooling load is only 3/4 ton. I spent years studying this stuff before designing and orienting the house on our land. Now I need to do something about our water heater, as it's the single biggest energy hog in the house. I've toyed with the idea of building a solar collector and tying it in somehow with the electric heater.

 

[Greg Riutzel]

The best water heaters I've seen were the gas on demand (point of use) heaters during my Navy days in Spain. Instant hot water when you needed it and Hollywood showers never went cold. They were usually vented through the wall by the appliance. I don't like the ones offered here in the States. They're way too big and complicated compared to the simplicity of the European models. No energy waste with storage costs and purging cold lines. Recirculating systems may help, but still it's extra components and cost. It's interesting orientation is brought up. That used to be a thought out guide line especially for farm houses in the Midwest, but Levittown and suburbs has pushed that into dusty archives by developers.