Heat pump adjustment

[twfsa]

I have had a heat pump (16 seer) 3 years now, and am very satified with winter utility cost, I live in the midwest and the winters can be brutal. I have the outside thermostate on the unit set to operate down to 17 degs.

So far this winter the elecrtic bill has been no higher than $75, the n/gas bill $68. Maybe $5-$10 in past years higher.

I have a set back thermostate, set back to 67 at night, 69 during the day and 73 in the evening till 10:00 PM.

I received a notice from the electric utility to set it and forget it to save more $$$.

My house is a ranch, 12 yrs old, 2K sq ft.

Whats your opinion?

Thanks Tom

[Dr. Hardcrab]

No offense, but opinion on what? You made a bunch of statements. My opinion is that you are bragging and not really asking a question.

;-]

[Bishoop]

Your gas/electric bills are simply amazing. My electric bill in Florida during the winter runs not much less than your total for gas/electric.

[Chub]

that's what you're supposed to do with a heat pump. set it and forget it.

[Bob]

The notice you received was intended for owners of heat pumps with backup electric resistance heat. With that type, it usually costs more to warm the house back up in the morning than a person saved the previous night.

[Dick]

I have never understood that philosophy. Following that guideline, you would also set your air conditioner at one temp and never change it. Heat pumps and air conditioners are basically the same animal. The heat pump just has the ability to reverse itself to extract heat from the air. Our new Trane heat pump came from the factory with a set-back thermostat. And that's exactly how we use it.

[twfsa]

The notice was to owners with heat pumps with n/gas back up.

Tom

[Bob]

Did the notice actually say natural gas backup on it, or was it a generic type notice that could have been sent to all heat pump owners? Does your electric utility also deliver natural gas, or do you get that from another company?

[twfsa]

The notice said, Attention heat pump owners (with a natural gas or propane furnace). The gas company is a seperate utility.

Tom

[Dick]

That doesn't make any sense at all. Our heat pump has natural gas for backup (Dual-fuel, 100K BTUH gas heat.) When it comes on in the morning, it takes only a few minutes to get the house up to 72 from

1. If we let the heat pump do it by itself when it is 18-degrees F outside, it would take all morning. I will take a few minutes over a few hours any time from a cost standpoint for either gas or electricity. I might understand the suggestion if heat strips were used for backup, and the cost of electricity per KWH is high in that location. But surely not for natural gas.

Dick

[Bubba]

If your furnace only takes a few minutes to raise the temperature from

65 to 72 when it is 18 degrees outside then your furnace is grossly oversized! How do you feel burning all that extra fuel you never needed and getting those hot and cold blasts of air? Bubba

[Bob]

In that case, either someone at your electric company is seriously misinformed, or they are deliberately misinforming the public so they can sell more electric. In the majority of cases, it's definitely cheaper to set a heat pump back at night if the fuel used to raise the temperature the next morning is natural gas. You might even try to find a better 'economic balance point'. Did the installer do a Manual J heat loss calculation and come up with the 17 degree balance point? If he didn't, then try moving the balance point up to 30 degrees and see if you save more money.

[Dick]

I really doubt that. We don't have hot and cold blasts of air. Our system performs beautifully. The sizing of the heatpump was done by an engineer with a masters degree in refrigeration. He is also a West Point graduate. The dealer he works for has the best reputation in town. The furnace part of the heat pump and the a/c part are exactly the same size as we had before in a Day-Night gas pack. 100K heat,

48K cooling. The heat pump just runs far more efficiently than the old gaspack, and even with the huge increase in energy costs, our total energy cost is running about $100 less per month than it did last winter with similar degree days. We live at 5,000 feet where it snows in the winter and gets over 100F in the summer.

[Bubba]

An Engineer? That pretty much explains it. You dont know better if you've never had it. Bubba

[Bob]

Don't worry about Bubba, he's nasty to everyone.

[Stretch]

Tom,

If you have electric resistance heat backup, setback with a properly sized system will increase your electric bill. This is because you shut off your cheap heat, the heat pump, at night. Then you do recovery with the expensive heat in the morning (The resistance heat). The resistance heat only gives you 1/3 to 1/2 the BTUs per watt that you get from the heat pump.

If you have gas backup, setback makes much more sense. However, if you are recovering quickly, your system is oversized. Sounds like your Master used the 500 Sq. Ft. per ton rule. This is the national average installed sizing for the last 50 years. They use it from Maine to Florida. Your "Master in refrigeration" sounds like a hack. If he did a true load calculation, most likely the size of your equipment would have been smaller. My 2000 sq ft house in hot humid Myrtle Beach SC only needs a 2 ton heat pump with 4 KW connected backup resistance heat to maintain year round comfort. Of course it depends on your insulation, exposure, weather conditions and amount of glass, but your system would perform even better if it were sized properly, which I doubt it is, from the information you provided. Did The "Master Of Refrigeration" actually show you a degree from a REAL University? The salesmen around here tell all sorts of lies, which no one ever checks up on.

Stretch

[Dick]

I would call West Point a "real" university. He was also a Major in special forces. I didn't see his sheepskin for his master's degree, but I remember it was a major university, and in my discussion with him there was no doubt as to his credentials. I think he has been in HVAC for about 12 years. He is not their salesman, per se, he designs the systems for their customers.

[Bubba]