Actual cost of intstalling geothermal

[Stretch]

In our area the ground loop adds about $3,000.00 per ton to the installed price of a heat pump. You will need to size the WS HP for heating load, OR size it for cooling load and add backup heat for the difference between the house heat load and WSHP heating capacity. If humidity is not a problem in the summer, sizing for heat load will give highest insatallation cost and lowest winter operation cost. If humidity IS a problem, Size for cooling load; lowest installation cost and lowest summer operation cost, but higher winter operation cost.

Water Furnace has an excellent reputation. I don't know the other brand.

Get a load calculation done. See if your power has a rebate program. They might do the load calculation free, ours does.

Stretch

[Tony Karp]

We're going to be getting some estimates for geothermal for our house and I wondered if anyone here could give an estimate I could use for reference against the quotes I'll be getting. Here's our info:

Location: Northern Virginia, just north of Manassas, about 30 miles west of DC.

Heat range: As low as 6 deg in winter, to about 95 in summer.

House: Two story colonial with about 2400 sq ft. No basement, just a crawl space.

Current hvac: Central heating/cooling. Fairly new oil furnace (Armstrong Air Ultra 80) and aging Ruud A/C.

We don't use the A/C that much, because we have installed fans in the kitchen, bedroom, etc. We keep the house at about 70 deg in the winter.

Last heating season, we used about 900 gallons of oil (it was colder than normal).

We have an acre and a half, so there's plenty of room to drill or trench.

Local dealers sell Waterfurnace and Econar.

Our main motivation is the price of heating oil contracts which went from $1.25/gallon last year to $2.00 for this year. Probably be $3/gallon next year.

Any thoughts, suggestions, or rough guesses about what it would cost to switch to geothermal.

-- Tony Karp, TLC Systems Corp Techno-Impressionist Museum:

TLC Systems:

[nicksanspam]

You might also consider a sunspace or solar siding.

NREL says 1040 Btu/ft^2 of sun falls a south wall on an average 30.6 F day with a 40.1 daily max in Stirling VA, when a square foot of south glazing might collect 0.9x1040 = 936 Btu and lose 6h(80-35)1ft^2/R1 = 270, for a net gain of 666 [evil] Btu/day.

So you need about 900x100KBtu/5006DD = 18K Btu/DD, eg (65-30.6)18K = 618K Btu on an average January day, which might come from 618K/666 = 929 ft^2 of transparent polycarbonate siding.

More house insulation and airtightness could help as well.

Nick

[Dr. Hardcrab]

"Tony Karp" wrote

We were selling oil at $1.64 a gallon all last winter (we are right across the river from you), but I agree: Who know what it will be next year.

I have an air source heatpump that I am very happy with, but my only suggestion to you is to call a MINIMUM of 3 companies to come out and give you a price. However, as many have stated here before, it's the INSTALLER that is more important than the equipment. Ask your friends or neighbors who they use. Someone with a proven track record of professional installations and reliable service is who you want to go with. Don't base your decision on price.

[Duane Bozarth]

WHY??? What was the estimate for the conventional system? Something doesn't sound right at all.

We did a Water Furnace retrofit (trench) into a ranch w/ full finished basement of roughly same size (actually about 3200 sq-ft total) for roughly $5k over conventional in Eastern TN--not much different climatically than your area, either.

[Tony Karp]

Geothermal estimate was high 30s. Way too high for a house like this one.

We will probably be replacing the A/C in the next year or so, and I'll look at one with a heat pump then

In the meantime, we'll be looking at ways to make the house energy efficient. Last year, we replaced the windows. This year, we're replacing the front door (it's very thin) and adding insulation above the house.

I was thinking also of adding a ridge vent above the house. We already have gable vents with a fan, but that doesn't seem to do much.

-- Tony Karp, TLC Systems Corp Techno-Impressionist Museum:

TLC Systems:

[Tony Karp]

Geothermal estimate was high 30s. Way too high for a house like this one.

We will probably be replacing the A/C in the next year or so, and I'll look at one with a heat pump then

In the meantime, we'll be looking at ways to make the house energy efficient. Last year, we replaced the windows. This year, we're replacing the front door (it's very thin) and adding insulation above the house.

I was thinking also of adding a ridge vent above the house. We already have gable vents with a fan, but that doesn't seem to do much.

-- Tony Karp, TLC Systems Corp Techno-Impressionist Museum:

TLC Systems:

[Dr. Hardcrab]

One of my customers wanted one and my company does not install geothermal units. She had a 2 1/2 ton system put in for just under $11K. Don't know if that is a good price or not.......

[Duane Bozarth]

....

An "electric furnace" other than some (standard) resistance "emergency heat" resistance elements shouldn't be necessary at all if you have sufficient ground loop capacity--and if you don't have sufficient ground loop capacity you don't have a geothermal system. It got to -22F one morning in Knoxville and the backup heaters only ran for a short time at that. Our installation had an outside thermocouple set up to keep the resistance heaters off until air temps were below 20F -- never felt a need to raise that setpoint.

You need an onsite sizing calculation and evaluation for loop placement/installation by a competent Water Furnace distributor/installer. I'm guessing it will cost from $5k to $10k more than a high SEER good quality air exchange system, but ime the operating costs will compensate for a great deal of that and the comfort factor of the higher quality heat relative to the air exchange unit will make you relish it. Plus, the lack of noisy air exchanger outside for the air conditioning unit is another plus....

[Tony Karp]

That was why I posted the specs for our house here and asked for a guesstimate.

The high 30's was an over-the-phone estimate from a local contractor, given the same info I originally posted here.

They said I would probably need a four ton unit.

We have an oil furnace, but that would be have to be replaced with an electric furnace for supplement>T>>

-- Tony Karp, TLC Systems Corp Techno-Impressionist Museum:

TLC Systems:

[Tony Karp]

I think we will try again next year.

Right now, we have a full list of repairs/improvements: Replacing screened porch and patio, tightening up house, adding new insulation, extending the heating/AC into other parts of the house, etc, etc.

I was surprised by the high over-the-phone estimate we got, and there may have been a misunderstanding. Next time, I'll have them come out to the house and take measurements.

[Duane Bozarth]

....

What about "some (standard) resistance "emergency heat" resistance elements" was unclear in my previous post????

If the unit isn't working, yes, the resistance heating elements will come on--what I was pointing out is that there should have been nothing about an alternate electric furnace in the cost proposal as was apparently told to the OP. The geothermal heat source/sink should be adequate for normal heating/cooling source/sink for something like 95% so the "emergency" elements are simply that. If the system is sized such that they are required for a significant fraction of the heating period, the system is too small and will be cost-effective. As for the "necessity" argument, if your gas furnace blower were to fail or you were to lose electric service when it were cold you could easily be w/o heat, too.

[Duane Bozarth]

????????

[HeatMan]

Duane, when I took a geo class, I found out all Geo units come (fairly) standard with resistance heat back-up. I didn't think much of it at the time, but what would happen if you blew a compressor (or a similar problem) during the winter. Heat is a necessity, AC is a luxury(or so they say).

[HeatMan]

yeah, yeah, yeah, whatever.....