APS Electric (campers, price, move to)

[Potential_Landlord]

I cannot understand how people do not use AC in today's weather. The house most go up to the low 80s and it only cools down noteworthy around 8pm. But then there is no wind and it takes time to cool the house back down. This affects quality of life meaningfully. Anyways, to each his own.

[AZ Manager]

Originally Posted by HX_Guy

Is it a desire of just not wanting the AC on or a money saving one? Cost wise for the AC to run 1 hour is about $0.75.

No need to have it running. I'm a solar household so this time of year it won't cost me anything to run the AC, really it will cost me a tiny bit on my credits that will be cashed out next month. It was 84 outside today in the far NW valley and only 81 in the house even with the turkey cooking. With ceiling fans running on medium or low it is plenty comfortable. In the summer my AC is set to 75 since we are all home all day it never goes up.

Probably also depends on how much southern exposure you have. South side of my house is garages and my office so none of the main rooms are heating up from direct sunlight.

[HX_Guy]

Wonder how close to each other we are...I’m in the NW Valley too, or as I saw on a Facebook page, the “Upper West Side” We’re off of Lake Pleasant and Happy Valley Rd, also solar home.

[hikernut]

Originally Posted by Potential_Landlord

I cannot understand how people do not use AC in today's weather. The house most go up to the low 80s and it only cools down noteworthy around 8pm. But then there is no wind and it takes time to cool the house back down. This affects quality of life meaningfully. Anyways, to each his own.

It depends on the house. We've had our heat pump off since at least the beginning of November. It gets up to 75-76 in our great room, and that's only because we leave the patio door open when we're at home. I close up our bedroom during the day and it's 72-73 in the afternoon.

[Ponderosa]

Originally Posted by Potential_Landlord

I cannot understand how people do not use AC in today's weather. The house most go up to the low 80s and it only cools down noteworthy around 8pm. But then there is no wind and it takes time to cool the house back down. This affects quality of life meaningfully. Anyways, to each his own.

I kept it at 74 yesterday with AC. I'm sick of the heat and I am not going to sit in at 80s plus house on Thanksgiving when its off peak.

[AZ Manager]

Originally Posted by HX_Guy

Wonder how close to each other we are...I’m in the NW Valley too, or as I saw on a Facebook page, the “Upper West Side” We’re off of Lake Pleasant and Happy Valley Rd, also solar home.

I'm at Jomax and Dysart, few miles west of you by Vistancia but not in.

[teeej]

I've had the A/C off for a month. I kept it at 78 during the summer, but my thermostat's been in the low 70's for a while.

[jlawev]

Originally Posted by AZ Manager

The way you mention demand I'm not entirely sure you understand how that is calculated. Not trying to be insulting here so please don't take it that way. Your demand is calculated based on the highest single usage at once, so all appliances running at the same time. Your AC unit's demand is the exact same if it is set at 60 or 100 there is no difference in how much electricity it is using in any given minute while it is on. So your demand for the month can be set if your AC kicks on one day in the entire month for 5 minutes or if it running 24/7 the demand is the exact same for that one appliance, lets assume absolutely nothing else is using electricity for simplicity. As far as demand is concerned 78 and 83 mean nothing if it turns on once during peak hours at 83.

I'll try not to take offense

I do understand (I think) how demand works and have been playing that game with APS for 7 years now, but it's always good to challenge my understanding. While you are right that the demand of the AC itself is the same in your 5 min vs 24/7 example, the APS peak usage demand calculation would result in far different results since they average it over a 60 min period (i.e. every hour). For example, given a baseline household demand of 2kW and an AC unit that pulls 8kW, your 5 min scenario would result in an APS hourly demand of 2.67. Your 24/7 scenario would result in an APS hourly demand of 10.

Relevant PDF from APS.

Originally Posted by AZ Manager

The real issue with demand rates is around cooking dinner since those appliances have huge bursts of energy usage, microwave and oven, and add a lot of heat to a house causing the AC to turn on at the same time. Lets say you decide to make a roast for dinner so you turn the oven on to heat up and you turn a burner on at the same time to brown roast in a pan before it goes into the over. You may even microwave some frozen vegetables for a side and while cooking you are in and out of the fridge getting everything you need to cook with. Your oven heating up and a burner on is now your monthly demand plus the microwave usage and the fridge has heated up from being opened so that turns on and now you are running 4 high demand appliances at once setting your demand for the entire month. Add your AC onto that because that oven heats up the house and you are easily at a demand rate of 10 or more for the entire month based on one dinner, and it only gets worse if you had used hot water to wash some dishes or something before cooking the hot water heater is still on. This nightly routine for most households (I'd assume but who knows) is the target of APS with demand rates.

If you want to cut demand costs your AC temp isn't a very effective way to do that since it's electricity usage is static while on no matter the setting the only thing the temp difference does is change how often it turns on and how long it runs while on but neither of those will effect your demand rate. More reliable and cost effective ways to manage demand is to turn the AC off completely while cooking so it doesn't turn on when the oven/microwave are on, manage oven and microwave usage if possible so neither is running at the same time, wire in a timer to your hot water heater is a minor way to cut demand but with the new rates would probably only take 1-3 years to return its cost in savings (they don't use a ton of electricity at any one given time but they do use a lot over the year and we have hot pipes in the summer anyway so it doesn't really need to be on all day), and don't run small appliances during peak hours (coffee makers, stand mixers, etc.). For summer demand if you manage everything right the lowest demand rate you are going to see is probably a 6-8 which is your basic electronics (TVs, computers), fridge, and AC all at once. You can't predict when the fridge is going to turn on (it is 53 outside at 8 am with all my windows open and my 3 year old fridge is running as I write this post) so you will inevitably have the fridge and the AC on together at some point during the month. Didn't mention the dishwasher or laundry because no one who watches their electricity usage so much that they keep their house at 83 will have them on during peak hours anyway.

Again, it's averaged over an hour so bursts are not as damaging, although still to be avoided. While I love the idea of turning off the AC completely while cooking and using other appliances (incl tv/av receiver), it's just not feasible in my family short of using a load controller. So far I haven't gone that far, but these new rates may push me over the edge.

So my strategy as it stands today is to reduce AC load as much as possible. With multiple AC units in the house this becomes even more complicated. As an aside I really wish I could get a few smart thermostats that could communicate with each other and only come on in alternating fashion.

So back to your 78 vs 83 example, an AC set at 78 is going to run much more often and much longer than one set at 83. This will in turn increase the likelihood of it being on while other appliances are on and bring up the average of any given hour and lead to a (much) higher APS hourly demand on top of using more on peak kWh.

Originally Posted by AZ Manager

As for wear on the AC unit itself they are designed to turn on and off repeatedly. Running it for hours on end as people do when pre-cooling can cause excessive moisture build up on the coil and that moisture will freeze (picture below of a 4 year old unit completely ruined in a rental where the tenant has been for 6 years and they used to pre-cool to 68). Over time that can cause corrosion on the coil, especially on the outsides where the piping is larger so there is more area for moisture to collect on. That corrosion will causing the rusting shown and will lead to a coolant leak which will cause the AC to run longer since it isn't blowing as cold and eventually stop cooling altogether. A similar problem occurs when the filter isn't changed regularly enough, lack of proper airflow causes odd suction so the condensate stays on the coil instead of dripping off. A cheap coil replacement is probably $1500, the one in the picture cost me $2200 last year (again on a 4 year old unit).

Your point on pre-cooling is well taken. Honestly when I mentioned trying out pre-cooling, I don't think I would go much lower than 74-75. I would continue to disagree, btw, that AC units are designed to turn on and off repeatedly.

[jlawev]

Originally Posted by HX_Guy

A little bit TL : DR but I wanted to point out that with APS, Demand is not measured at the highest point during the month, its actually measured over an entire hour and resets every hour on the hour. So it doesn’t matter if you have your AC, dryer and oven all running at the same time, or if you have your AC run for 20 min, your dryer for 20 min and your oven for 20 min, your Demand will be the same. With APS, your Demand is essentially the same as your highest one one hour of electric usage for that month, during on-peak hours.

Ah you beat me to it. I should have read through the replies first.

[jlawev]

Originally Posted by Ponderosa

I'm not sure that I understand your post completely, but if you are thinking peak demand is instantaneous use this is incorrect. It makes a difference both what you use and HOW LONG YOU USE it. A huge difference. The whole enchilada, because usage is averaged over the hour. My peak in winter is usually 2 or less and my ac runs often either for heating or cooling, but it does not run very long. In summer it will run flat out for an entire hour in August and peak demands in August are around 7. Anyway, here is an explanation from APS. I may have linked this earler, so apologies if that is the case:

http://www.azenergyfuture.com/getmed....pdf/?ext=.pdf

Again, sorry, you beat me to it... with the same pdf and everything.