Want to know how to save over $3,000 a year on utility costs? GO GEOTHERMAL!!!

This house had a 120,000 BTU Trane XV90 gas furnace that was 11 years old and in not so great shape, it also had a Trane 5 Ton XE1000 air conditioner with a flat charge and an 11 year old inefficient 50 gallon propane water heater.

http://youtu.be/egt5n_j93L4

We installed a WaterFurnace envision two stage ground source heat pump with intellistart and desuperheater function attached a Rheem Marathon preheat storage tank and a Rheem Marathon electric water heater. We added some return air for the system and installed two Honeywell Prestige HD thermostats with a Waterfurnace two zone intellizone system.
Ground loop was a 600' long trench with a 6 pipe racetrack for 3,600 feet of 3/4" HDPE piping and supply and return lines that had about 100' each underground before going to the house.

Customer received their first bill and it looks like electric went up about $150, but propane is obviously no longer used and was hitting $600 in similar months. We expect an average of $300 per month savings. As always let me know what you think.

Good video. Just curious, why didn't you use slinkies?

I personally don't like slinkies as much, I know many will disagree with this but... I think they are not as efficient, if pipe is looped over more pipe it is wasting pipe and not getting ideal heat transfer. If i have the land i like a racetrack any day of the week. They look better, they install very easily, they keep the loop at an even pressure and are not wasteful of pipe, but this is just my opinion.

If I was in a situation where there was very little land, a slinky would be the only way to go unless drilling then I have another opinion, but as you can see there is more than enough land.

I"ll bite.
What is your other opinion?
Eric

It's beautiful.

Was a comparison of ASHP performance and cost made for that Oregon location?

Posted By ICFHybrid on 25 Nov 2011 10:18 AM
It's beautiful.

Was a comparison of ASHP performance and cost made for that Oregon location?

Yes it was, this location is a bit higher up than the Portland area so they saw a lot of freezing temperatures and snow. Secondly the wife HATED ASHP's and the colder temperatures they output from the registers, the wife says she can't tell the difference between the propane furnace and geo unit. Lastly the furnace, and AC(was flat on R22) were in pretty bad shape and the WH was time to be replaced so doing a full new system cost the same as the geothermal after tax credits and rebates and wouldn't be nearly as efficient or comfortable.



WaterPirate, what do you mean you will bite? I don't have an other opinion I am just not a fan of slinkies even though I know most use them. I may be wrong here but... if pipe is overlapping pipe then we are wasting pipe correct? A lot of my "green" customers want as little was as possible in all aspects of the system. I like the racetrack because my crew is used to installing them so we can get a loop done in a day vs trying to properly space slinkies and undo the coils. Then there is the issue of equal pressurization of the headers, by the time we are done our longest and shortest circuits are usually within 12" of length of each other, its much harder IMO to do slinkies. Part of it might just be that I have never been taught the proper way to use slinkies that make them equivalent to a racetrack.

Sky, how many feet of pipe do you get in a foot of trench with your race tracks?

Dean, what do you mean? Its a 66" wide trench in most cases with a little bit of over digging so 6' of pipe per 1' of trench? I know that you can get more with a slinky per foot of trench but there is only so much heat in each foot of dirt. In my area we almost always use racetrack/horizontal and just don't do many slinkies unless absolutly needed due to land constraints.

I am not saying there is anything wrong with what you are doing....just wondering

Do you have your own excavator?

No i subcontract out the digging. We only do 10-15 jobs per year, which is actually a lot in this area. Geothermal is just not as necessary when we don't get over 100 degrees and don't go below 30(except a few days per year) and have relatively low electric rates. There is still a big market for it in this area just not many people know about it. I joined this forum to learn more as i have fairly minimal knowledge of geothermal yet am one of the larger companies in the area. I really wish we had more of it here as it is my favorite type of system to design and install, i just don't get to do enough of it.

Secondly the wife HATED ASHP's and the colder temperatures they output from the registers

Do Tranes blow cold air? I grew up with a heat pump (get in the way back machine) and even back then I don't remember cold air blowing. I'm 300 miles North of you, subject to Inland Canadian Arctic Air Blasts and heat pumps do just fine up here, particularly the newer ones. We probably have deeper colds than you do in the Portland area and more heating degree days. Has it been a long time since the wife had a good heat pump? Is there a reason they didn't go radiant in the first place?

Are performance standards the same, or at least similar for heat pump air handlers as far as leaving air temperature is concerned?

Trane's latest variable speed air handlers have delay on and slow ramp up to minimize cold blow complaints. They call it "Comfort-R" mode, and it basically lets the coil get good and hot before moving too much air across it.

ASHP's are much better now than they used to be but sometimes there is just no convincing people who have had them before or have friends who are unhappy with them now and compared to ASHP's when it gets into the 30's with no backup heat coming on yet a geothermal unit is much warmer/more comfortable heat at the register. I like geo heat better than ASHP heat any day of the week and in my house I have a Trane system with a Comfort-R motor thats only 3 years old, it just doesn't compare at lower temperatures when we are in the mid 30's and just above the temp when electric resistance comes on. Part of the reason you may have had a warmer heat is that in the more northern climate your electric resistance heat comes on more often, therefore heating up the air to a warmer temperature?

As for radiant, the house was about 10-12 years old so retrofitting it in would be expensive! The ducts were already in so we added more return air, sealed up the ducting and added a zone system because the second floor was always so much hotter or colder than the main living area. So far the results are fairly good, we are expecting an increase in electric of about $150 next month(and we are so far having a wetter and colder winter) vs the cost of propane in the $450 to $600 and up range for the same months last year.

Asian minisplits claim viable heat pump operation down to below 0*F

Carrier has jumped onto that bandwagon with their GreenSpeed intelligence systems.

Part of the reason you may have had a warmer heat is that in the more northern climate your electric resistance heat comes on more often, therefore heating up the air to a warmer temperature?

Don't know what my folks did growing up - they were sorta in charge of that. But, if the solution is to set the resistance heat to burn earlier, why doesn't /didn't everyone just do that rather than be uncomfortable with the older units?

vs the cost of propane in the $450 to $600 and up range

Hate buying propane..... So, what's their time to payback with this fine new system?

We have installed quote a few of the Mitsubishi Hyperheat modules and Carrier is not even close to the first one to do it with their Greenspeed. Nordyne has a Panasonic VFD(Variable Frequency Drive) compressor in their iQ Drive systems that has been out a few years. I have also installed Mitsubishi PUMY/PVFY units which are inverter driven outdoor compressor with variable speed indoor unit. For some reason Carrier just has marketed much better than others who have done it before them.


The payback on the system itself should be in the 5-7 year range if you look at just the system, things that needed replacement like water heaters were added and upgraded and the zone system was also an upgrade, if you add the upgrades in about 7-8 years the barebones system should pay itself back in 5 years with current propane and electric rates.

I find the payback on ASHPs to be similar to payback on geo (with tax credits out of the equation). The numbers on both ends of the geo are simply bigger.

Regarding slinkies, if one uses design software such as Geodesign you will find (at least in my AO) that horizontal 6 pipe actually calls for more feet of pipe in the ground than a slinky at the same depth. Ergo the Climatemaster design program suggests that the slinky is a more efficient heat exchanger.
To take the thought process a step further We get 600' of pipe into about a 110' trench. That said, I have less feet of pipe in a running foot of trench than a 6 pipe horizontal. Therefore, I actually have 10% more earth to draw from with a slinky than the same amount of loop in a horizontal track. Job I'm designing this morning suggests 2120' of slinky vs 2400' of horizontal six pipe. While not exact, the difference is awfully close to that 10%.

Conclusion is the feet of earth you are exposed to is more important as the feet of pipe.......again in my AO.

The biggest thing to remember is that all systems that are designed correctly work fine.

Posted By SkyHeating on 25 Nov 2011 02:51 AM
I personally don't like slinkies as much, I know many will disagree with this but... I think they are not as efficient, if pipe is looped over more pipe it is wasting pipe and not getting ideal heat transfer. If i have the land i like a racetrack any day of the week. They look better, they install very easily, they keep the loop at an even pressure and are not wasteful of pipe, but this is just my opinion.

If I was in a situation where there was very little land, a slinky would be the only way to go unless drilling then I have another opinion, but as you can see there is more than enough land.

I am not sure why looks matters, 6 ft deep.
We installed both, racetracks and slinkies, and found the slinkies much easier to install. I guess it depends on what you have a good routine in. We took a poll around our installers, and no one wanted the racetrack.
It is easier for us to prepare the pipe outside the trench, and worry about distance between the pipes in the trench.
BTW, what makes you think that you cannot balance the pressure between slinky loop in the same way you can balance it between straight loops? Slinky loopfields have proven themselves to work as efficient as racetracks or other horizontal heat exchangers, and require lesser excavation.

It is my experience around here that the younger guys do more 6 pipe work/ spend more time on site- in the trench.
Older guys have more room to store slinkies built off site and don't care to go in the trench at all.

Depending on where you are.... slinky's may work for you... Go into frigid temperature areas, they don't work very good. You need at least 25-30% more pipe, and a lazy mans way of doing the install. Long term it's harder on the system, they are NOT as efficient, as racetrack. For the most part the "older" guys are the problem. They have learned to do it the way everyone said to do it 20-25 years ago.. Well that's what ruined most people's thoughts on geothermal... most didn't work properly. Most put in too small of systems, then undersized the loops for the undersized units... Now not all are still in this category some of the good old boys have adapted but I still run into it all the time.