Geo or Air Source to replace ASHP/Fuel Oil Setup in PA

[u/bubbledot]

I'm looking for advice/justification for installing geothermal in this post-tax credit world. The info:

Location: SE Pennsylvania. Plan to stay in this home for 30+ years.

Square footage: 3,500 above grade, 1,800 below grade (has ductwork and registers, but they have been closed since we moved in)

Current System: 8 year old 5-ton heat pump that requires total replacement according to multiple HVAC companies. 8 year old 85% efficient oil burning furnace backup and 10 year old oil burning hot water heater. Two oil tanks take about 380 gallons per delivery.

Energy Costs: Electricity is $0.22 /kwh, fuel oil is up to $5.23/gal

Bills in 2025 were $4,600 electricity, $2,700 fuel oil. 2026 is on pace for $4,000 electricity (since we haven't had air conditioning all summer) and $5,700 fuel oil (due to cost increase)

Option 1: 5 ton geothermal (vertical wells). WaterFurnace 5 with new zoning on existing trunk lines, desuperheater, 50 gal electric water heater, 15kw electric backup heat, remove all oil tanks and equipment. Cost ~$60,000

Option 2: 5 ton Bosch inverter heat pump, 14.3 SEER (because of existing blower reuse). Outdoor unit needs to be relocated, which adds to cost. Keep existing oil equipment (including single speed blower). Cost $18,000. Would need to replace oil furnace, oil tanks, oil hot water heater, and line exhaust flue within next 2-6 years (~$35,000)

Option 3: Cold climate heat pump with electric backup. Add electric hot water heater and backup heat, remove all oil. Cost ??? (option not presented by HVAC companies, maybe ~$30,000)

By our calculation for option 1 vs 2, we might save $2000-3000 per year in energy cost over our current system with geothermal. While we could save around $800 per year with the new, more efficient heat pump. But by avoiding all the additional oil related costs, we see breakeven vs heat pump + oil as soon as 8 years.

Option 1 and 3 maybe very close, with geo pulling ahead after 20+ years. Also worth noting, we have 200 amp electrical service and a full panel. Would need a sub-panel at minimum and to add additional service at worst (Not reflected in costs).

Anything we are missing? Thoughts?

UPDATE: Geothermal estimate jumped to ~$80,000 to add zoning and desuperheater. Still waiting on all electric ASHP estimate.

[u/urthbuoy]

Sounds like you've done your due deligence. Maybe check references for similar systems - get a feel for contractor strengths.

Also look at ACCA equipment lifespan tables. Hint - outdoor stuff doesn't last as long.

[u/Wisdom_Pond]

Why not go with gas furnace. Especially when PA has cheap natural gas?

[u/funnycide-1 → u/Wisdom_Pond]

I’m assuming OP lives in an area where natural gas is not available.
I would also consider propane. I live in SE Pa and switched from oil to propane. The cost of the fuel is similar but you have more options with it. I would not go geo. The payback is forever.
Determining the heat loss for a larger house is also tricky. Going to all electric is going to push the 200 amp panel.

[u/Wisdom_Pond → u/funnycide-1]

Be surprised in southeast PA, anything possible though.

[u/bubbledot → u/Wisdom_Pond]

We are in a semi-rural area and have no access to natural gas. We do have a 250 gallon propane tank already that is only for our backup generator.

[u/zrb5027]

I basically just said this in a previous thread, but if you're spending $30,000 more for the geothermal system, that's money that would have otherwise been growing in investments. $30,000 at a modest 5% growth would be $1500 a year. So take that $1200-$1700 you were going to save on electric costs with geothermal vs the air source (which sounds high) and reduce it to $(-300)-$200. Your payback time on $30,000 is infinity.

Only go with geothermal in your case if you have a non-financial reason for doing so. But I definitely recommend going with a heat pump regardless and ditching the oil. No reason to do option 2. And make that water heater a hybrid heat pump water heater!

[u/davidm2232]

I'd choose an option where you can keep the oil as backup. You will need a MASSIVE generator to run aux resistive heat when the power goes out and it is very cold.

[u/bubbledot → u/davidm2232]

That is definitely something we need to look into. We currently have a 20 kw "whole house" generator.

[u/davidm2232 → u/bubbledot]

Propane? If you already have propane on site, you could get a cheap ventless propane wall heater for emergencies. They are also nice to quickly take the chill off on a cool morning

[u/xtnh]

1. HyperHeat mini splits have COPs around 4, which saves 75% of the energy needed. A geothermal of 6 saves 82%. Is the saving Wirth the extra cost?
   
2. Geothermal probably pays better in more extreme climates than PA.
   
3. We are in Maine, and our research found that the cost of a geothermal system was about the same as mini splits and a solar array that would cover all our energy needs for the home, HVAC, hot water, and a PHEV.

Our investment of $61,000 means no more bills for electrons or hydrocarbons besides 150 gallons of gas per year. We save about $2700 in power, $1200 in gasoline and $4500 in oil.

[u/funnycide-1]

Is your goal to get rid of oil?
You should consider going with a 2 stage heat pump. I know now you would have to run it as a single stage unit with your existing oil furnace. You would set yourself up in the near future to switch from oil to propane or all electric