Thanks again, Teddkid, Beenthere, and Gravity. I will take some of all your advice, and the debate has been instructional.
I will see if I can lower cfm, first, just to 1000 from 1033, and then see how it does at 950. Hopefully that gets me near .5 static pressure.
Since it has only run on high fire 250 hours (lifetime service hours, I love the data this stat makes available) over two winters I am probably quibbling anyway. It has run on low fire 517 hours, the rest on heat pump. So it runs on high fire 4% of winter hours, low fire 8% of the time and off or in heat pump mode the rest.
I will think about locking it in high fire. I like the fast option for morning warmup, but I do want it to be capable of low fire on really cold days when I want to maintain temps.
As far as an audit goes, I had a free one from the utility, just a walk-through, no duct leakage or house sealing testing.
But they could not find a lot. I installed house wrap very carefully and sealed around windows when I resided the house a few years ago.
Last year I airsealed my attic and crawl space, and spent several weekends applying goopy mastic to ducts and then wrapping with insulation. I am big into building science. At each step, I could tell a huge difference. For example, after air sealing my attic, my bills went down, but in addition, I did not have to use a humidifier last winter on cold dry windy days as I used to have to do.
I have found that Teddy Bear was right in that keeping humidity under 50%, my son's dust mite allergy went away.
On your homescale, TeddKidd, it was a bit difficult since it is not made for dual fuel, but I converted my gas use to kWh and have a total annual energy use of 16,167 kWh. That put me a touch below "high efficiency home." My annual energy use of 16,167 includes heat, cooling, lights, hot water, everything. My bills over a year for gas and electric combined is $1200, about half of which is heating and cooling, so even if I can find a way in this old 70's house to cut another 20% on heating and cooling, that's only $120 a year. So I am going to skip the duct blaster and air leak testing. If I seal too tight, I won't get any air changes.
The bathroom mirror only fogs up when I am taking a shower, not overnight when the heat is off. So I am not overly concerned with moisture damage to my house--I keep an eye on relative humidity indoors, and have good bath and kitchen vents.
It probably would be cheaper if I kept the house a constant temp 24-7, so the heatpump did all the work, rather than have the night setback, but the difference was about $30 a year. For $30 a year, I am going to enjoy the cool sleeping hours and the wonderful whoosh of that furnace reminding me I got fifteen more minutes. Since the furnace is in a closet across from my bedroom and between my sons' bedrooms, not much chance I will hear nothing. But I like that sound--it is not loud, and it is comforting.
. Although it does sound nice.
