We live in Ontario where electricity is based on time of use (for most of us). This winter will be the first time we have been under this plan. Here are the relevant details:

1. We have a ClimateMaster TTV027 unit 2. Our electricity cost from November to April is:

7pm to 7am - 5.9 cents/kWh
11am to 5pm - 8.9 cents/kWh
7-11am, 5-7pm - 10.7 cents/kWh

There are a hole bunch of other charges the province adds to the bill so the true cost is the cost I have recorded plus 8 cents or so.

My home is also an R2000 home so it is well insulated. Given this price structure, does it make sense to heat the home to a higher temperature at night and set the thermostat so that the furnace does not typically come on during the peak hours?

A hydronic system would have allowed much easier storage of low cost heat in a water tank. Retro fitting thermal mass to an air system isn't so easy.

I'd slightly overheat the house from perhaps 5-7 AM and then setback from 7-11. This provides a warm wake up and minimal use during 7-11 high cost interval.

Then I'd heat just a bit extra from 3-5PM so as to be able to set back from 5-7 PM to avoid that high cost interval

If it is an R2000 house it should hold enough heat to be comfortable during a several hour setback

With so little peak rate time I don't think the expense of converting to a hydronic system is justified.
I like curts plan.
j

Just be careful... Especially in dead of winter. Keep in mind the heat pumps depending on manufacture usually give somewhere around 20 degrees f rise. Here is where I will be attacked probably but I disagree generally with most recommendations in this forum especially when people in canada read it..... This is generally an american forum so keep in mind most people here are from much warmer climates than ontario. In fact there is quite a difference from southern to even northern ontario, its quite large and design temps change a lot. Generally when I install heat pumps I try to size to 100% heat loss. I've never had a customer have a problem with heating their house and having some spare capacity, just for reasons like this. When its at its coldest setbacks can be much more costly than just simply maintaining the heat. Also depends on your set back. If you go 1-1.5 degrees then first stage will kick in to bring back up only cost around 50-70% (again depending on whose equipment you have) of second stage. Pretty much most thermostats will call for 2nd stage where there is a 2 or more degree rise. When it hits dead of winter and your heat pump is sized to the max it will call on auxiliary heat (5 times more expensive than the heat pump). Plus in the rating system with the smart meters you also will be charged I believe for peak load. Heatpump, plus electric heat, plus load of house you may hit some pretty high bills due to the setback. Be careful my advice would be to go no more than 1.5 degrees as setback in winters when temp is past 0 degrees F or -15 degrees c.

I wouldn't let a minor detail like poor thermostat design influence heating strategy. There are ways around the second/third stage issues.

I agree, because of my install designs I use, either honeywell's pro 8000 tstat and wire them up for emergency only, but I also design so the heater isn't required.

Sorry to continue. Using touch phone and accidently scrolled over and it hit submit

I also really enjoy the new ecobee tstat. So far seems pretty good. A little more pricy but you get wifi hookup and interface. There's an extra module (of course more money). With that you can connect upto 4 sensors of your choice. Once you get used to it and know the right information about the sensors its not too hard to program. All available and recorded on the web interface (suggestions would be loop in, out temps and air in, out temps). Also sends programmed alerts on the sensors high temp/low temp if a cottage or remote location could do indoor and outdoor sensors, etc.).

100% load or 93% load can both be strategies that are favorable based on geography, application and price/kwh.
I've been put in my place often enogh round here to try to avoid "absolute" statements.
j