New vs Old

Chevra

I purchased a house about 6 months ago with a geothermal system. It has worked good all winter. My only concern is the age of the unit now. One of the stickers on the unit says 2001 and that seems to line up for what the previous owner thought. I have no idea what has been replaced since then. The previous owner is not the one who had it installed, but we are friends and a couple years back he had a contractor come out and run some tests on it. Everything was working as it should.

So my main question is, are new modern units that much more power efficient? If something major was to fail on this one would it be worth buying a brand new unit, or just replace parts as needed? I just want to prepare since this thing is getting up there in age.

Its also been hard to find information on this one so I imagine parts could be an issue as well. Sticker indicates: Made in Canada. Has a MCI logo and model No. W/A-35-Cu-H.

Mad Dog_2

I think the wisest thing you can do is have an expert specialist in Geothermal from here at The Wall, come assess it for you, in person. Then you'll know for certain. Mad Dog

hot_rod

I would guess compressor technology has improved, and inverter drive, variable speed are becoming more common, so that efficiency could be much better. And with a variable speed compressor cycle efficiency could improve.

I see more and more geo pump modules using ECM circulators, so a 50% or more improvement in power consumption on both pumping and compressing is reasonable.

Are parts even available for your unit? I can't imagine you would put a lot of $$ into a system that old?

search around online and look at new geo units and see what features they offer

Illinoisfarmer

Hey! Finally something I know about…

I built our house in 2006 - we had a GSHP installed at the time. A year ago, I got thinking about the age of the unit and the incentives for replacing it - and priced a new one. My trusted contractor did a heat loss calculation (the old unit was sized correctly), and sent me a proposal. I'm sure the price was fair, but I thought "It's working fine, why not buy a new Polaris with that money". Thats what I did. That was in March of 2022. Fast forward 2 months to June of 2022. We were pretty busy spraying, and working long days. I got home to a house that was 80+ degrees and the breaker for the geo unit was tripped - I reset it. Kaboom! It wasn't one of those tripped again a bit later deals either - it was a BANG and flicker the house lights and tripped immediately. I sheepishly called my trusted contractor, who sent a man out and determined that the main board was shorted. Unfortunately, there really wasn't a way to determine what caused the board to short without replacing it, and here again, I have some experience. In farming, we call that process 'throwing parts at it'. Not the contractors fault at all, but it was clear that I was going to be spending money on parts that weren't returnable with no way to tell if they were going to solve the problem.

I decided it was time to replace (well, past time to replace). I looked a 'true' variable speed unit, but opted to go with the same type 2 stage unit we'd had before (different brand). The new unit is supposed to be more efficient, it has the ECM pump motor that adjusts flow to meet the load, and it's darn nice looking (if you like that sort of thing). I can't really say that its using less power, our bills have never been that bad. If you're looking to replace based on energy savings, I really doubt you're going to come close to making those numbers work. I also don't think the house is any more or less comfortable, I didn't really have any complaints before. I will say that the new unit is quieter - the old one didn't seem noisy, but there are times I don't even realize this one is running.

In a nutshell, if you think the old one is going to quit and you want to replace it, whatever. I'd advise doing that about 2-3 weeks before the old one fails 😁. If you are thinking the savings will pay for the replacement, that hasn't been my experience.

hot_rod

I would say the power consumption would drop with a newer more efficient unit. But if the cost of electricity continues upward, the operating cost could, probably will go up at some point.

The manufacturers of the equipment should have charts showing efficiencies at different operating conditions.

Lowering the load, or running lower operating temperatures would also drive COP, saving KWh.

EdTheHeaterMan

@Illinoisfarmer I like the way you think. "Replace about 2 to 3 weeks before the equipment fails." I wish that everything worked that way! Bet the Polaris is still just as much fun! Who needs to eat anyway. Food is so overrated. Said the tradesman who just ate lunch to the farmer 🙈🙉🙊

EdTheHeaterMan

@Chevra there should be some energy savings with variable speed units not so much with single stage units. But the cost difference will be something the consider. AS The @Illinoisfarmer said, he replaced a 2 stage with a 2 stage and there was little if any noticable savings. So if you go with the lower cost replacement ther may be no savings other than service and repair cost. Go with the higher efficient model and you will get the lower operating cost.

Hot_water_fan

@Chevra since you've been there 6 months, can you tell us how many total kwh your home has used this winter? And a general location? That can kind of narrow down if any efficiency improvements are worth the squeeze.

jumper

Theoretically variable speed eliminates stop/start so motors, compressors, and pumps last indefinitely. Only the solid state stuff wears out and that is relatively easy to replace. Unless it becomes difficult to obtain. Energy savings is difficult to predict. Those solid state variable speed drives cannot be 100% efficient.

kurtFisch

A old saying comes to mind “if it ain’t broke don’t fix it “ that being said, see if you can look up the specifications on your unit and compare to new efficiencies, if that’s not possible at least compare current draw with rated BTU’s at a given load , that should give you a ballpark estimate of the current efficiency.
I have a 21 curt freezer from the 70s that I removed all the fiberglass and replaced with foam it does not run any more than a 5 yr old next to it. If well made it may have as many yrs left as a new unit. Good luck, Kurt

pecmsg

Much more doubtful. 

If you save 10 or 20% I’d be surprised. 

A new unit will supply more comfort. 

ethicalpaul

I would have to see some hard fast numbers to convince me that you'd be able to make up the replacement cost in operating savings. It's just too big a number and as you know with Ground Source, you are basically getting a really good efficiency all year around (compared to Air Source).

The only thing you would be buying would be peace of mind IMO. That is worth something, but only you can say how much.

If it were me, I'd run that thing until it blew up, you are in the golden years of payback now where it's all gravy

Chevra

Sorry for the very late reply on this. I guess life got busy the last while.

A little more info on my situation. I am located in Saskatchewan, Canada, so it is cold for half the year. Most of the time very cold. I didn't have any issues with heat. Heat from a Geo unit is definitely different then Gas forced air that I am used to but it was still very comfortable. I couldn't really calculate how much power it was consuming because my shop was using electric heat as well. Turns out the shop was using a ton of power. Near the end of winter I switched that over to a propane boiler and my power bill went down drastically. Now I can better estimate what the Geo is consuming but the weather has also changed for the better.

I am leaning towards just running this unit until it fails. Ideally it will fail during the summer months but does a person ever get that lucky? Maybe price out a new unit just to see. I feel like my money is better spent on maintaining this unit for now. Whether I get a contractor to come in and service it or I tear into it myself. Main thing would be making sure the coils are nice and clean to get maximum heat/cooling transfer right?

I appreciate everyone's thoughts and previous experiences. Sounds like variable speed would be the way to go if I ever do replace it.

@Illinoisfarmer My money also goes towards a few Polaris machines sitting in the shop

leonz

A coal stoker stove will save you a great deal of money and make a lot of heat using your western Canadian Sub Bituminous Coal which is cleaner burning coal.