View Full Version : off peak / on peak thermostat
I have tried to explain this to my hvac installer, but he hasn't tried this before and said he would if it could be explained what thermostat, timer etc he needed. Here is the scenario: I have a 3 ton Westinghouse 13 SEER heat pump just installed June 2006 in my new house. I can get the numbers of it, just don't have them with me. I am signed up with my electric company for buying electricity with on peak prices and off peak prices. During the winter, on peak is from 6am - 10am. During this time, our family is up and getting ready for work, school etc. Through calculation, it is cheaper to not have the auxiliary heating strips to come on during this time and to only have the heat pump running. I have a set of gas logs that if the unit requires the auxiliary heat, it is cheaper for them to provide the auxiliary heat during on peak times. It is on its own separate thermostat. If I used a programmable thermostat that sets the temperature back on the heat pump, and use the gas log thermostat, the air handler fan cuts off and doesn't circulate the air even if the blower is on for the gas logs. If I can get the unit to cycle those on, the fan for the air handler needs to stay on to circulate this air. I would like to be able to turn the logs on and off at other times manually independent of the heat pump during off peak times. Is there a thermostat that can do this and if so, could someone point us to the rep at the company that can speak to my installer to explain this. If someone has another strategy, we are open to ideas. Thanks in advance for the help.
11-29-2006, 03:37 PM
could probably mount a sensor on fire place to start fan.
11-29-2006, 04:38 PM
Even at peak rates the heat pump's heat is probably reasonably economical. But you wouldn't want to run the strips along with the heat pump during peak time.
Your installer can probably put the heat strips (and the heat strips alone) on a timer that keeps them from running during that time, even if the thermostat calls for auxiliary heat. This could be done on the low voltage wiring at the air handler.
This way, anytime the gas logs will be on, the heat pump (and blower) will be running anyway- but you won't get the strips coming on at peak electric rates, either.
11-29-2006, 05:02 PM
okay I'll try to explain this. get a thermostat for heat pump with programmable fan' that means fan will run continuos during occupied period.program hp tstat for occupied between 6am-10am set the heating set point lower than the gas log tstat that way the hp fan will run but unit will not call for heat and if it does it will be 1st stage heat(heat pump)not aux. heatstrips. the heat strip should not be disabled for any reason or controlled by stat,timer or other as they are needed should the unit require a defrost cycle.One question though how does power co know when you are using the power? are you sure you are not confusing winter rates with summer rates? oops sorry that was two questions
Ok, thanks for the replies, very helpful. My power company knows when and how much by the type of meter I have. It is a special meter that is digital and records kW used on peak and off peak. There are summer on peak periods and winter on peak periods. I am being charged 5.8 cents kW offpeak and 25.5 cents on peak. I usually save $40 - $80 per month by shifting my power usage to off peak and basically cutting everything unnecessary off during on peak. I already have timers on the hotwater heater and outdoor lighting to basically cut all high wattage appliances off. Now, trying to explain this to my hvac installer has been intriguing, but he is willing to try. I'll tell him to check his vendor for a thermostat with a programmable fan mode. I checked what he installed and it is a White Rodgers non programmable digital. The gas logs have a millivolt type thermostat which is programmable. It is correct that the heat pump is more economical even during on peak times, except for the heat strips.
11-29-2006, 10:16 PM
believe a honeywell vision pro will let you program run times for the fans. a timer to kill power to aux strips is a no brainer to do.
Should I suggest a th8320 or the 8000? I am printing this post so he can read your suggestions.
BTW, I would not be prying so hard for info, but my installer "seems" to be uninformed on this type of installation. He keeps telling me he only installs White rodgers tstats. I may be asking for more than he feels comfortable doing, but he did a very neat install job, and does not ignore my calls when I have spoken to him about other concerns. I want him to do this if at all possible.
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