Getting dry in the house!

[Rangerbait]

Makes sense, but in cold weather each running flat out is 3 kW, so 2units x3 kW x24 hours = 144 kWh/day. The rest is most likely backup strip heat spiking the demand.

I just did a bit of reading on that...turns out we do a lot of what is recommended against (keeping thermostat above 68 degrees, cranking it straight to the desired temp when getting home instead of gradually turning up), and are probably using the backup heat strip a lot more as a result.

I'm used to natural gas furnaces, and have never had to worry about that...great tip, thanks.

 

[mwhitnee]

I love my antique kettle lol I have on the top of my stove, it holds about 2 gallons and I fill it every day as it evaporates every day. Simple, but big difference in the air.

 

[DickRussell]

......that's a drop in the bucket compared to what the electric heat pump draws on a cold day...had a 380kWh day on Sunday when it stayed in the teens all day and everyone was home...

Geez, I feel bad for you. I have a GSHP that draws 1.7 KW per mfg tables, so for a cold day averaging about 15 F outside (about 80% of design delta T), that would cost me about 32 KW per 24h day, or 979 KWH/month. Actual bump in total electric bill during coldest winter months is about 700-750 KWH. Over the weekend, though, I had a problem. The water valve failed, and I had to switch on the emergency heat, meaning the heating was done with 6KW worth of electric strips. That would have been 144 KWH/day if flat out, although a typical winter day would call for heat a lot less than 100% of the time. I had lost about 5 degrees off setpoint when I realized I had a problem, and it recovered on electric heat in about four hours, but still, that's more than I wanted to let go for long. I fiddled with the actuator on the valve and got it to work again. But I figure it's just a matter of time before it fails again, so I ordered a new valve. If I had to, I could heat the house with just the little woodstove, but I'd have to run it maybe 15 hours cranked up, and I'd go through a lot more wood.

 

[woodgeek]

What your BTU demand Dick, it sounds like a pretty tight structure.

 

[DickRussell]

What your BTU demand Dick, it sounds like a pretty tight structure.

It is very tight, with a final blower door test of about 0.8 ACH50. The heat pump is a two-ton, 25 KBTU/hr in second stage, but in practice it never leaves first stage. The house takes so long to respond to changes in outside temperature that it's never really in steady state. But my best number on heat loss at zero F outside is about 19 KBTU/hr actual, vs. heat loss model giving 22. Not bad for 4000 sqft conditioned space, but that's what any new house up here ought to be. Building "to code" seems to me to be a wasted opportunity, when something like 5% more in construction cost can make it right. But that's off-subject for this thread.

 

[Rangerbait]

The house takes so long to respond to changes in outside temperature that it's never really in steady state.

I have serious insulation envy. It seems they have either some pretty lax codes, or very forgiving inspectors because our place built 10 years ago is drafty af.

My wife and I just decided to start looking for a piece of property to build our own place, and do it right. The amount of money it'd take to get this place where we want it is a non-starter.