So we have a 31 year old Heil AC unit and an 11 year old Frigidaire heat pump at our house. We avoid running/touching the Heil unit at all cost because it is expensive to run and looks like it should just crumble into a pile of rubble if touched.
We had a company come out and do a check the units and the tech indicated we have mold in them. I wasn't totally surprised but I also have some reservations with the tech from 'And Services'. I initially decided to sign up for a maintenance plan with them but then realized (a few weeks) later that if something goes wrong with the Heil unit specifically, they were not really going to help me other than probably quote me for a replacement unit. I'm not even sure they use equipment we would be interested in - I got sucked into the 'free checkup' invitation from them while browsing stuff at Lowes one day. Yes, that is how these types of issues start.. decisions without research. Still waiting on a call-back from the 'And Services' manager to cancel my agreement.. not holding my breath though. I'll make time soon but at the moment I'm tied up trying to find company and technology solution that provides the best value along with prepping to start a new job.
So technology wise, there are a few options available for replacing our heat pump and AC.
- Standard heat pump.
- Variable speed/capacity standard heat pump (usually advertised as using an 'inverter')
- verify whether they are referring to fan and compressor or just fan - having both is where the real savings comes from.
- ductless mini-split heat pump
- Geothermal heat pump
The list is roughly in order of price. I'm waiting on a geothermal quote which will be high but right now there is still a 30% federal tax credit which is may make it feasible for us.
The first 2 options are a cost vs efficiency trade off along with the question of reliability. With the increasing importance of energy efficiency, I suspect that long term we will see 'standard heat pumps' go away in favor of only equipment that has variable speed/capacity. In general, I've generally heard that these units last ~8-15 years here in Florida. A few heat pump people keep telling me averages are under 10 years locally but I'm not sure if that is true or just misinformation to promote their units.
The "ductless" mini-split has benefits over the regular/variable speed-capacity heat pumps - efficiency (unclear how much - possibly very dependent upon the particular install), either no or much less duct work and simple zoning.
The major mini-split downside is cost which is significant. The units are supposed to be easier to install which makes me wonder why the installed price is so high - seems to me that installers are charging a premium for mini-splits. You may also not like the look of the inside unit on your walls but some brands offer nice solutions which look like standard vents but at a premium cost. It isn't clear what to estimate the lifespan of these to be. I think there are a few blog posts indicating that people have had some units last over 20 years. Since we may have mold in our ducting (which is fiberboard and harder to clean than metal as I understand) it would be nice to not need cleaning/replacement of the duct work. I've not seen tax incentives for mini-split units which is surprising - it would certainly help promote the technology.
And the last real option is geothermal. We had geothermal up north and liked how it worked but had a nightmare with the initial company/install. The installer had his (subcontracted crew?) finish quickly one day and they hooked the lines up wrong (2 inlets hooked together, 2 outlets hooked together and 1 inlet/outlet pair done correctly) which caused a couple $400 electric bills instead of the pre-geothermal costs of ~$150. On top of that, they didn't tighten the wiring in the disconnect well and almost caused a fire. Of course, they went out of business that week and the way they worked the warranty - they took over the warranty from Water Furnace. So when they went out of business we had NO warranty at all.
After that, why on earth would we consider getting geothermal again?
- Getting consistent heating/cooling from the ground is simpler than getting it out of the air because ground temps are much more stable. The average ground temp around here (Florida) appears to be ~72 degrees at a few feet down. If cooling with outside temps in the 90's, that low ~72 degree ground around the underground loop has an easier time adsorbing the heat than the 90 degree outside air would. Heating uses the same principal but in that case the ~72 degree ground more easily provides heat than say 25 degree outside air. Nationally, I think the average ground temps are something around ~50-70 degrees so geothermal works anywhere.
- Having all the mechanical parts inside the home and out of the weather means less wear/tear due to environmental issues.
- The 30% federal tax credit is back in-place through 2019. It is on a sliding scale for 2 years following that and after that it currently is expected to end. It appears that this would apply to our entire install including tying into the pool.
- With a titanium heat exchanger in the geothermal unit we can use our pool as the first level heat sink which will warm the pool. Our pool is shaded about 70% and is usually 10+ degrees cooler than those in direct sun - which means we are not using the pool as much as we would like (and should). I hate to take the tree down that shades the pool because I like the shade most of the time since I burn easy. I don't want to put solar heating loops on our roof (which we just replaced due to a number of leaks) and risk future leaks. I could maybe put solar loops on our metal workshop but I'd have to research that a bit - of course, that is partly shaded as well which limits the usefulness.
- I expect the lifespan of the geothermal unit at 20-25+ years without much trouble. I suspect this will vary more due to the installation than the equipment itself.
- The earth loop should last 50-100 years which reduces any future replacement cost by a pretty large amount.
Downsides
- Equipment is much more expensive.
- The vertical loop(s) we need are probably more expensive than a horizontal loop. We just don't have enough lot for a horizontal loop though.
- Always a chance you could have problems with the earth loop/wells.
- Usually fewer companies work with geothermal which tends to drive up prices for maintenance plans.
- Probably will need significant ductwork for our whole house replacement of the current 2 units.
Now there may be some additional benefits to going geothermal with "the right company". The last fellow I spoke with mentioned that his son or son-in-law does tree work and that his company is also licensed for plumbing because of the geothermal work. The reason this might be a benefit is - we are on a septic system (no city sewer on our street) and our drain field has been acting up (aka trying to backup and/or not drain as we add 'stuff') and he might be able to do include that in our project as well. The idea being that doing one big project will hopefully be cheaper than doing 2 smaller projects. Really the downside here is that it will be expensive no matter what we do.. although doing them separate would let us spread the bills out. Anyways, this is certainly worth investigating.
A few places I used in researching:
- https://www.pickhvac.com/heat-pump/
- https://www.pickhvac.com/geothermal/
- https://www.pickhvac.com/ductless/
- https://www.pickhvac.com/hvac-warranty-guide/
- https://www.angieslist.com/articles/geothermal-energy-unit-worth-cost.htm
- https://www.energystar.gov/index.cfm?c=most_efficient.me_geothermal_heat_pumps
- https://www.homeadvisor.com/cost/heating-and-cooling/install-a-geothermal-heating-or-cooling-system/
- https://www.forbes.com/sites/tomkonrad/2012/07/02/waterfurnace-7-series-vs-climatemaster-trinity-geothermal-heat-pumps-the-best-of-the-best/#63ae086a5bf1
- https://www.forbes.com/sites/insights-inteliot/2018/09/14/cover-your-assets-the-rise-of-the-super-intelligent-supply-chain/#6303e8499858
- https://www.energy.gov/eere/articles/5-things-you-should-know-about-geothermal-heat-pumps
- https://www.apartmenttherapy.com/daikin-ac-mini-split-air-conditioner-review-258610
- http://www.ahrinet.org/Home
- http://hvacradvice.com/site/324/About-NATE/Find-A-NATE-Certified-Technician
- https://www.hvac.com/faq/best-central-air-conditioner-warranty/
- https://hvac-talk.com/vbb/forum.php
Some of the companies that may be viable.
- Water Furnace
- Amana / Trane / American Standard
- Mitsubishi
- Daikin
I found the following link REALLY interesting but not really of relevance in our local area right now. I can envision "HVAC Cooperatives" kind of like electric cooperatives in areas.
https://www.engadget.com/2018/09/28/dandelion-alphabet-geothermal-heating-new-york/
After going through all this research, I am still debating what to do. I still have another company coming out and I am waiting on a quote from someone that did come out. One thing I am sure of though - the lack of a good installer will waste the capabilities of the best system. I'll update this as I get more information.
Ecclesiastes 2:26 New American Standard Bible (NASB)
26 For to a person who is good in His sight He has given wisdom and knowledge and joy, while to the sinner He has given the task of gathering and collecting so that he may give to one who is good in God’s sight. This too is vanity and striving after wind.
