I’m looking for some help/guidance. I’m still optimistic but discouraged so far with our short history with geothermal. We live in Rhode Island in a 2500 sf four square colonial with 2 ½ floors of living space. Bought the place last spring, had all the plumbing/electrical updated and spray foamed all the exterior facing walls (average R-17), basement rim joist (R-20), and roof deck (R-31) in anticipation of new geothermal installation which replaced the old oil furnace / steam radiators with new ductwork and the geothermal system - open loop (new well), with 2 ClimateMaster Tranquility units - a 2 ½ ton unit for the first floor and for the 2nd /3rd floors a 3 ton split unit with the ClimateMaster compressor in the basement and a Bryant air handler on the 2nd floor. The 2nd/3rd floor unit has a zone control with separate thermostats. The system also has a desuperheater which connects to a new high efficiency 80 gallon electric water heater. Our first bill representing a full month (January 2011) was $572.00 (3593 kWh) with the 1st and 2nd floor temp set at 70/72 degrees - at this point we do not use the 3rd floor at all so it’s set at 59. We use no oil or gas. Understandably, our electric bill is going to be baseline high given especially with a newborn and toddler but I was really discouraged to see this bill. Is this electricity use what we should expect for a January in New England? Any comments, thoughts, suggestions are very much appreciated. Thanks in advance.

What was your electricity bill before?

E.G. in the moths without geothermal? A house like yours usually has a base electric bill of $120 may be, so about $450 is due to geothermal. We (in western New York) see heating and cooling bills of about $300/ton/year (incl. DHW), so you have about $1800/year to expect, a few dollar more with colder weather or higher thermostat settings. So you should see about $400-450 per month in December, Jan + Feb, with much lesser costs in Oct, Nov and March+April. So you are on target to $1800 annually. Wait for the remainder of the year, everybody gets a sticker shock in December for electricity after putting a geosystem in. Again Geo is one of the cheapest ways to go, but it is not for free.

I wonder if the thermostat is engaging aux unnecessarily. Please list the make and full model number of the thermostat and we can review the settings if you want. I'm much more familiar with non-zoned systems, but we can still look at it and ask questions here if we are unsure about a setting.

This may sound strange, but have you checked with the pediatrician and respected medical web sites regarding recommended day and night time temperatures for the kids? It was much cooler than we originally thought.

Edit - Aux may be working as intended, but settings are worth checking.

Thanks for the replies. This is a new home for us so we do not have any prior electricity bills to compare. I certainly understand that geo is not free so as long as we're in the ballpark of what to expect, I can handle that.

I was also wondering if the aux may be engaged when not necessary. Our thermostat is a ClimateMaster ATP32U03 or ATP32U04 - not sure which one but it is programmable.

I can check with our pediatrician but I think my wife will trump the doc's input!

Funny. I deleted it, but I had typed "Having paperwork in front of me (from web sites) helped to convince my wife"! But don't win the battle but loose the war, or you might be the cold one! :-)

Wow, there are many ways of controlling engagement of electric heat with this thermostat. Discuss them with your installer before changing anything to make sure he/she is on board.

You can download a manual here: http://www.climatemaster.com/index/res_stat_ioms

Options include:
"Smart Recovery"
"Smart Heat Staging"

Do you have an outdoor temperature sensor installed? If so, you could use the "Electric Heat Lockout" feature. This will prevent electric heat from energizing unless the outdoor temperature is below the temperature you set. To be safe, remember to disable this feature if you go away.

Read the "Temperature Algorithm" section. You have some interesting options to choose from in there as well.

Generally, minimizing, or eliminating, set-backs helps reduce aux engagement. I usually suggest setbacks of no more than 2f. You could potentially do more without aux engaging (depending on the settings you choose) but recovery time is s..l..o..w with geothermal (without aux.) More like s.....l.....o.....w, so you may not be happy with the recovery time. No point in setting back excessively just to need aux to help the system recover.

You have some reading to do. I do not know how zoning plays into these settings (for the zoned unit). Another good reason to check with your installer.

Thanks geome. I'll review the manual. The Smart Recovery option is already on. We only have a 2 stage system so looks like the Smart Heat Staging isn't an option. I'm not 100% sure but I don't think we have an outdoor temp sensor. At least we don't have one on the north side of the house. Will also double check to make sure our setbacks are no more than 2f. I wonder how the 3rd floor zone plays into the equation. It shares the 3 ton unit with the second floor but we really haven't turned up the thermostat there beyond 59. Guess I'll have to check in with my installer.

Does the upstairs temperature actually stay at 59 or does it run a bit warmer, milking heat from the lower floor?

My mistake, it's set at 57 and it does run a bit warmer. Right now it's 61.

What that means is that the 3rd floor is being heated by the lower floor - that zone isn't cycling on much, if at all.

That's what I was thinking. Not planning on using the 3rd floor much so will probably keep it set where it is. Just want to maximize efficiency and minimize the electric bill! Again, jaw dropped with the first electric bill but if the Dec-Feb months are balanced out by the rest of the year we'll be ok.

Look at the whole year, and your dropped jaw should come up again, slowly turning into a boyish grin. And yes, 72 degrees is uncomfortable for a newborn unless he/she is sleeping naked and does not get a blanket. How can you sleep at 72 degrees? Is the A/C in the summer kicking on at 70F?

What were your electric bills in Sept/October? I realize this is a new place, but seems like you have owned the place since "last spring". $572 seems a bit on the high side but without a base line it's really hard to say.

Not sure if this can help put in perspective- live in New Brunswick Canada.   I have a 3500 sq foot house(includes teh sq footage of my walk out basement), 8 years old, regular type contruction, on the ocean (windy), converted from oil in late late 2009.   Installed a 3 ton W-W system for infloor heat. keep the house at approx 68-69F . Also added an electric finishing DHW tank (60 gal).    2 x 260 foot wells drilled into the rock.  My off season daily electric consumption is approx 17 KWh per day and during the past 2 months is averaging 57 KWh/day-   up here that equates to approx $7 per day for heating and other electric stuff my hotwater.    it is close to 40KWH/d or $4 for heat and pre-heating of DHW.   I was spending almost double  that to keep oil in the tank.  actually closer to 3 x.   depends on the price of oil.

Is it just me or at a glance does 5.5 tons so heavy for this house?
It like to see the design and calcs.
J

Thanks for the posts. dgbair, I don't think our electric bills since the spring help too much. Most of that time the only electricity we were using was for lights and tools (nail gun compressor, floor sander, table saw, etc.) and the bills were never higher than $11. November was up to 880 kWh ($140) but we did not move in and start using appliances (and geo) until mid-December and December we used 2300 kWh ($360). Fred, thanks for the New Brunswick perspective. I guess I'll have to wait it out and look at the average for the year. Your last 2 months at 57 kWh/day looks way better than the 100+kWh/day that we're looking at for January.

Good point- 57kwh/d was for Dec and Jan. Jan was colder and the average for Jan could be closer to 85-90+ It has been a lot colder in Jan vs Dec

Ok jadin,
do you have any load or design info?
equipment selection seems questionable to me, which harkens concerns about the designer.
j

No unfortunately, I do not have load/design info. Only found this site and the helpful advice after everything was installed.

You might want to start assembling some of your own.
Start with a manual J load.
There is a user friendly private license one we like (hvac calc), but there are free ones as well.
Even previous usage and insulation might help.
Without a little data, your question is something like " how come I used so much gas to drive to Cleveland?" (What kind of car is it?- I dunno.....Were you towing a trailer?- I dunno..........Where did you drive from?- I dunno...)

(Trying to illustrate the impossible nature of the question, not pick on you)

With no other info, I would go with DocJ's assessment as he works fairly proximate to you. His gut reaction was you might be fine.

Good Luck,
Joe

Thanks Joe. I'll try to get a manual J load. We don't have access to much information on the previous usage and there was no insulation in any of the walls or roof line before we sprayed foamed the place. I can live with DocJ's initial assessment and will look for things to balance out once we're out of worst of winter.