Extension of: Fully Modulating Furnace, Regular or Communicating thermostat?

[duckman06]

Programmable tstats have LOST their energy star rating because they, on average, dont save that much energy

Gross is correct. Even energy star realized that programmable t-stats are not that great even when used propely.

The problem I see is there is always someone in the home that will miss with the t-stat to get the temp they want so there goes the program is always getting in other words getting overriode.

I conducted a test on my home along with some customers (friends of mine with newly installed systems). The test showed that finding at set point for each season and leaving it would be the same price if not cheaper to operate. I didn't just go by electric bill but also with kilowatt usage.

So my thoughts are simple. Find you a set temp for your home for winter and summer and leave it. It is one or have dozon of the other. Example try getting your home down to say 74 degrees on 100 degree day after programmable t-stat has held it at 78 till you get home. It will work harder in the evening when it is the hottest to reach the temp you want.

Now take that same home and set it for 74 degrees and leave it. When you walk in the door from work the home will be the temp you want it to be. It will use the energy all during the day or twice as much in the evening or night. It all comes to basically the same energy usage. Just my thoughts. My home sets at 72 degrees during the summer and 70 during the winter.

Average electric bill is $75 dollars for a 1695 square foot home with Trane XR15 (2.5) ton heat pump. I belive the highest bill I have seen with this system was $84.00...

[duckman06]

Not sure I understand all the new comments on "outsmarting the thermostat" and other comments.

I do have a large furnance because I need the fan flow to support the already installed AC load. As mentioned in previous threads, the AC can freeze up in hot weather because the flow should be larger. The city building inspector recommended that I go to even larger furnace to get even larger AC flow.

I am using three to four setbacks of temperature per day. Previous threads relate that designer of this furnace cannot deal with setbacks and that "all learning starts from scratch with a setback". I am trying in the wintertime to keep a low burn so that I get close to an 80% burn-on time in the house. Because of large 24' ceilings in main area, this keeps the air mixed and the overall temperature "pleasant". When I let the furnance go quickly up to 100% burn rate, I get very fast heat rise and the house becomes rather cold on the first floor becuase of the rather short 15-25% run times.

I use the "debug mode" of furnace operation to force furnace to go to lowest stage (I am told like 10-12% burn rate). This keeps the air-flow low and for the 2.5 hours this works, the 1st floor is quite pleasant and comfortably warm. I have tried to get PG&E's smartmeter readings during these times and it looks like my gas and electric bill are slightly reduced over the 100% ramp up mode. But the bigger factor is that the temperature says very constant for the 2.5 hours of low burn. That is what I am trying to get to happen during the 6-8 hour periods when I am home (more on weekends).

So I am trying to find a way to make the furnace stay in the low burn/low flow mode for as long as possible. My latest communications with the folks at Johnson Controls indicate that they are changing the debug mode to 95 minutes rather than current 150 minute mode. I am asking them if their fancy controller allows the user to control the max burn rate. Their answer is no. I am hoping someone will figure out their USB controller on the main board and allow user control of the heat section. If anyone knows of anyone doing this, please let me know.
tjcooper

What size A/C does your home have? There are smaller furnaces like a 80,000 btu that will cover up to (5) ton for cooling without going to 100,000
Btu furnace. In other words a (5) ton drive with 80,000 btu's is available on most model of furnaces. You are trying to take a system and make it work with a t-stat that you already have.

Since the furnace appers to be oversized I don't think you will every get it to do what you are trying too. It might be best to look into a lesser btu furnace with the size drive you need for cooling. This inturn will save you all the headache you are going through now.

[buzhall]

Go to dual fuel use a heat pump with gas as your aux heat

[Oregon Butch]

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[jpsmith1cm]

Oregon Butch

This is the Ask Our Pro's forum. In order to post a response here, you must have verified qualifications and have been approved by the AOP Committee. You may ask a question by starting a new thread.

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