By the way, all you guys who are trying to talk DW's into geo-thermal - how much will you pay me not to post this thread in to "home decorating" or "building new home" forums where all the girls hang out? I may get some of that new furniture after all!!! (Can you hear my evil laugh?)

Don't be hasty until you have the company that installed it check it out and let them know of your complaint. There could easily be a problem somewhere in the system(s).
Do you have any other appliances that use electricity? Water heaters will run the bill up fast. A pool? Perhaps you have another appliance not operating properly. Electric stoves/ovens?

Tell us more about your system, make, model, open or closed loop etc. It looks like your paying about 8.1 cents a kWhr. Find out what 'current' & 'previous' mean.

SR

House is total electric. Have not turned on the stove or oven except when installed :) No pool. Have kids that run computers and TV's non-stop, don't turn off lights and two large hot water heaters. Part of the problem is two-story foyer and living area. Upstairs thermostat is in bonus room. Right now thermostat is set at 75 and it's 78. Will have to ask DH for details on the unit, except I do know it's Florida Heat Pump, 11 tons. And BTW, the "D" in DH doesn't stand for "Dear" right now.

fsq4cw - this isn't first bill, just first bill since we've been living here a full month.

What is the average ambient been during the last month?

I live in a 1700 sqft house that has gas and electric. The electricity is over $200 a month now. You sound like you live in an efficient house with cheap electricity also.

beachgirl, obviously the bill is higher than your household had expected. What dollar amount had been expected?

That is a huge system for a residence.

With that large sized unit with some house efficiency, you should be capable of freezing sides of beef. The system needs to be tweeked. Maybe if you stage the cooling so that one system maintains the house, while the other systems are only used on hot days, the bill will drop. Get someone to troubleshoot the system to insure it is not leaking water.

If your hotwater is on hot instead of set mid range, the heaters will use much more electricity. With 11 tons of geo, the hot water that can be produced from waste heat during the summer, should not require much additional electricity for the water heaters.

how do you know that the bill is high? I would think the electric company should be able to recalc your bill based on some sort of heat pump and let you know the difference. Maybe your bill would have been $600!

First thing: I don't understand that electric bill. Either the "previous" and "current" numbers are in some units other than KWh, or there's been a mis-calculation somewhere. Start by calling the electric utility and making them explain the bill to you. Also, look for other fees on the bill -- assuming this is a new house, and assuming that you just moved in, they may very well have charged a fee to transfer the service from "temporary" to "permanant".

Did you just move in? If so, were there lots of doors standing open during the move-in process while the air conditioning was running? Also, how long has the air been on? If you just turned it on this month, and the house was hot before, it usually takes weeks for the structure of a larger house to cool down to room temp once the air conditioning is turned on.

And yes, an 11-ton system, if that's what it really is, is way, way too much for even a large house. I would have expected a system roughly half that size for the size of house you have. In fact, I'm surprised to hear that it's even possible to find an 11-ton system that doesn't require three-phase power.

i think you will find that the kids leaving the tvs, pcs, and lights on has more to do with it than the geo unit.

my house the HVAC systems turn completely off during the day when no one is home. but with all the electronics i have our electric usuage is MINIMUM of 2500KWH per month, and that is if it is a mild month and the HVAC never was turned on.

keep in mind that almost ALL modern electronics have standby current draw, that while minimal per device it can add up to a large draw when they all are plugged in all the time. get some multi outlet strips and plug your electronics into them. when not in use, flip the switch to kill power.

do the same for cell phone/ipod/whatever charges. if it has a wall wort, it is drawing power.

BTW, at over 5k sq ft your bill is very reasonable. my house is ~2400 sq ft and my lowest bill of the year was 230.00, but most months it is between 400 and 600.

I bet it's the 2 electric hot water heaters set too high, plus baths and showers each day for how many people, plus laundry and electric dryer how many times a week for same, plus cooling a 2 story foyer & living room.

Also, cellulose is good, but their sealing and caulking into the attic may be way off and leaking.

Without her husband's geo foresight, her username could very well be the-widow-beachgirlok instead, as she wrote out the $700 check for electricity and the $4,000 check for his funeral. ;-)

Okay, now I'm gonna go blonde with the questions. I thought that geothermal was supposed to somehow magically heat the hot water from the leftover heat that was generated from somewhere (yes, I realize how stupid this sounds, but I only remembered bits and pieces of DH's geothermal sales pitch - after a while I just went into my "special place" - you know, guys, that same place you go to when your wife tells you about the wonderful bargains she picked up at Talbot's, just before she tries on her treasures for you and asks you if it makes her rear look big - but I digress).

Dallasbill - I'm interested in your comments about the sealing and caulking of the cellulose into the attic being "way off and leaking". I say this because we have a 990 sq. ft. bonus room that is over the garage that is very hard to cool. The second story over the foyer and living room, as well as the two upstairs bedrooms and finished attic cool very easily. During warm days, the unit has to work non-stop to cool the bonus room (this is where the kids spend all their time with computers, tv's, and nintendo) and it will only cool to 78 when set at 75. The thermostat is in the bonus room, which makes it freezing in the other upstairs rooms.

On the positive side (don't tell DH - because I don't know if it has anything to do with the geo-thermal) 75 seems quite comfortable in this house. I'm very hot natured, and at our old house thermostats were always set to 70 summer and winter, and it still didn't seem comfortable.

Anyway, the hot water thing is something to consider, also. I like a hot bath, and we had the heaters turned up.

I am very curious about all your suggestions for the bonus room cooling issue. BTW it is L-shaped and has only one relatively small window, on the North side.

There might be nothing wrong with you electric bill. Your system may be oversized. However, if you really want the correct answers, consult a LEED accredited professional registered with the US Green Building Council and get your checkbook ready!

IMO

SR

Here is a link that might be useful: LEED for homes

The bonus room will be warmer unless you told the company doing the installation that it would have the heat loads from the electronics and bodies. It should also have a return duct in there to help should the door be closed.

Yes we men have a default "yes dear" answer when we are not paying attention to you. Nothing personal, just a survival instinct curtiousy of evolution. :)

it usually takes weeks for the structure of a larger house to cool down to room temp once the air conditioning is turned on.

Weeks??

From the questions you ask, you don't sound very blond. (dumb, space cadet, drugged) Post a question on the renewable energy site. (other forums, then renewable energy) You need solargary? to answer some questions. There are others on that forum that are probably better attuned to geo than the HVAC forum. We understnd HVAC pretty good, but geo is a little different.

Daddo, there is a return air duct in the bonus room.

Had the electric dept. out this morning (they sent four guys) and they spoke with DH. There is apparently nothing wrong with the calculations.

A big issue with bonus rooms over garages is the insulation in the floor. Spray foam is the best, to stop all conductive heat transfer from a 100 degree garage below. If they just pushed in fibreglass bats, there's an issue there. It will likely be compressed in a lot of places, thus rendering it half as effective as its R-rating. Likely a lot of voids, too, along the stud walls.

I doubt it's blown-in cellulose there. Do you know what they did?

And, how mnay times an hour does the system run when everyone is home? MAybe it's short-cycling, too -- another energy waster.

Dallasbill, it does seem to turn off and on a lot - is that what you call a "short cycle"?

Re: Bob Brown

While it never hurts to post on 'Renewable Energy' too, there in fact are a number of good posters right here.
Good suggestion though.

SR

If it's multiple times per hour, then "yes" it could be short cylcing. When it does that, it reduces the air temp quickly and does not remove humidity properly. It also does not runs as efficiently.

First thing: I don't understand that electric bill. Either the "previous" and "current" numbers are in some units other than KWh, or there's been a mis-calculation somewhere. Start by calling the electric utility and making them explain the bill to you.

Na, the math's right. With a house that size she's at / over 400A service and has 40:1 CT metering.

11 tons? One unit?

Before you condemn your GT unit let me tell you about my experience with my GT system. We moved in about a year ago and our house is a little over 5000 sq ft. Last months electric bill was $110. The previous two months $120 and $134. The AC has been on the last two months with the stat set at 73. We experienced one month last winter where the bill spiked to $600 (Feb 2007, coldest on record in last 40 years). There were some problems before we got our system tweaked to run as expected. One issue that caused the system to run more than it needed were the thermostats. The installer put in cheap single stage units for a multi stage GT unit. He had it set to "timer" for cycling through the stages instead of thermostatic conditions. The net effect was the unit cycled through 2 compressor stages and two aux heat stages every time there was a demand. We installed multistage stats specifically made for HPs and the system cycled only when needed. The electric bill was greatly reduced. Check the type of thermostats.

The second issue is that our new house had lots of big windows on the sunny side of the house. If you have the same problem put in thermal shades and if you can afford it automate to the time of day.

The third issue is that my HVAC contractor installed two units for this size house. One unit was 3 tons and the other 4, one for each floor. It sounds like your installer didn't size the system correctly with one unit at 11 tons. This makes your system inefficient.

The fourth issue is that, in reality, your bill is reasonable for the size house. It is also reasonable considering the fact that your have kids and that it is all electric.

Geothermal, when installed and tuned correctly is significantly better than using fossil fuels in terms of cost and impact on the environment.

I'm not sure what the big deal is. You might have to ask some people to tweak it to make sure everything is running ok, but what did you expect out of your electrical bill with geothermal ? $75/month ? I'm not sure the expectations are in line with what

The expected return of a geothermal unit is about 8 to 10 years. Factor that 20K over that amount of time and its about $200/month that you need to save to cover the costs (outside of time value of money).

What has been the average temp in your area during the day ? My guess is that that figure, while maybe a bit high is probably in line with geothermal unit along with other items. You do have some issues with the bonus room and other things - but that electric bill of 335 sounds very very reasonable. That could easily be $600+ for the temperatures you're trying to hold in your house.

If you really want to see some savings - bring your thermostat to 78.

I'm betting you're one of those people who reverses themselves in the seasons aren't you ? Whats your winter temperature set point ?

Contrary to what fsq4cw said, I don't think a LEED AP is going to be able to help. Unless they've done training outside of LEED specifically in HVAC systems. I say this b/c I'm planning on taking the test later in the summer (and just took a review class), and I don't believe I need to know the nuts and bolts of how an HVAC system is sized or supposed to work.

What you need is an Energy Star certified home energy rater. I don't know if it's universal, but the guy we used also did the ACCA Manual J calc.s for the new system we put in (HP, not geothermal, though) as well as sized and schematically layed out the ducts (ACCA Manual D).

The HERS rater can do blower door and duct blaster tests to see how leaky your home is in terms of air changes. These are pretty important, since there's a lot of detailing that's required to end up with a tight building envelope. If your builder and HVAC contractor weren't up to speed on that (neither of ours were), there could be a lot of issues that make the costs to heat/cool the house higher than expected.

Since this also sounds like a brand new home, I'd be asking my builder for their HVAC contractor's sizing calculations for the system. I'm surprised that the folks who've answered didn't mention that- generally, the first question for someone who's looking at contractors for a new system is "are they using Manual J?". That boat's sailed on your system, but I'd want to know how my system ended up that large, and I'd send a cordial letter to my builder requesting the information. Especially, since I'm assuming you're still in the warranty period.

But you have a big house, a massive HVAC system, and a lot of other things going on. I'd spend a couple months worth of power bills to have an independent professional check out your house and HVAC system to help you figure out whether there's a problem.

Here's a kinda catch-all document for ways to reduce energy use. A lot may not be applicable for a new house, but this covers many of the things already mentioned, plus a few other ideas.

http://www.southface.org/web/resources&services/publications/large_pubs/Home-Energy-Projects.pdf

I'd definitely re-set your thermostat higher, and you need a programmable that you can set even higher when you aren't there (during the day for us, since we both work). And, FWIW, our tankless heater is set at 105F and provides an amply hot shower. Mixing down from a hotter temp with a tank heater isn't a problem, but you're wasting energy if it's much above 120F.

Here are a bunch more useful documents:

http://www.southface.org/web/resources&services/publications/factsheets/sf_factsheet-menu.htm

Here is a link that might be useful: Energy Star rater search

beachgirl, dont know much about geothermal and hvac but i do know all about talbots. just curious when we do admit that your fanny is kind of big do you ladies mind? i have been wondereing about that for the past 47 years. thanks fred

First, 11 tons seems big for 5400 sq. ft. I have a 4,000 sq. ft. home and I have a 4 ton unit. Anyways, your bill seems VERY reasonable. In my area, 5400 sq. ft. would run between 500-600 to heat/cool. I personally pay about 215.00 per month (we have no kids yet) and sometimes 300.00 in colder months. In my opinion, your system is perfect, and very efficient. It is probably half of what it would be if you were running standard heat pump.
-Brad

If indeed you do have and need 11 tons for 5400 sq ft-you either have very poor insulation or one heck of alot of windows. I have 6000 sq ft and only have 8 tons total in three units. Most of the summer we only have to run the two 2.5 ton units. Our total electric bill averages 250.00 a month year round. (Trane geo units and a closed horizontal loop)