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ExtraSlow
07-07-2020, 06:42 AM
I know speedog and rage2 will have opinions for different reasons, but what's a normal temperature difference between floors in a two story home? Mine seem pretty high considering we run the furnace fan 24/7.
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speedog
07-07-2020, 07:05 AM
Your data points would probably follow along nicely with outside temperature data points, you should place a sensor somewhere outside where it'll out of the sun's direct influence. As far as why your home is doing what it is, I don't have a clue. Do you controllable zones on your HVAC? Is it an open concept home where air can flow freely from the basement to the second floor - my SIL's place in Tuscanny has an open staircase from the basement to the second floor, basement always cold, second floor always boiling hot and main floor varies wildly. There just is no way of controlling air in that home, open windows on the second floor to cool that floor down and the other floors get colder to the point of being uncomfortable.

ExtraSlow
07-07-2020, 07:10 AM
Here's the same graph with an exterior sensor shown too.
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No zones on HVAC, single furnace with AC. Top and main floors are open to each other. Basement has a door that is closed at night. AC thermostat is near the top floor sensor.

speedog
07-07-2020, 07:27 AM
I know speedog and rage2 will have opinions for different reasons, but what's a normal temperature difference between floors in a two story home? Mine seem pretty high considering we run the furnace fan 24/7.
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I wouldn't be losing much sleep over a 3-4 degree temperate swing over the course of the day when it appears your outside sensor in the north side of your home showed about a 13 degree swing in the same time frame. doesn't really appear to be an issue to me but than I live in a 1955 bungalow that has a main floor that has wild ass temperature swings during the summer, big roof area and not good airflow through the home, no AC either. Man, you'd probably be like some giggly school girl if I had your sensors in my home and sent you the data to analyze. Have another beer this afternoon when it warms up, that'll help

ExtraSlow
07-07-2020, 07:31 AM
I'm not so much worried about the "swing" as I am about the difference between the floors. Is that "normal"? I've always felt my AC had a really hard time cooling off my home, and I assumed it was because the fan was slightly too weak.

bjstare
07-07-2020, 07:47 AM
We are similar, but basement is even colder. 20c on the main will result in 21.2-5 upstairs and around 16.5-17 in basement. We have a 2 story vaulted ceiling open to upstairs from the main living room.

What’s your cold air return situation like upstairs? I know one of the drivers for my houses uneven temps is that the cold air return upstairs hardly sucks any air. One of the previous owners got rid of it when they did some renos, and I had to put one in when I did later renos... but it’s less than ideal.

Edit: that’s with our fan only running when ac is running. Rarely run a circ cycle, because it doesn’t help a whole lot (see cold air return comment).

If you think it’s because the fan is too weak, run it without a filter for a day. No resistance will let it push more air.

ExtraSlow
07-07-2020, 07:48 AM
I have cold air returns upstairs in each of the three bedrooms. they don't noticeably "suck" but maybe that doesn't mean that they suck.

rage2
07-07-2020, 08:01 AM
Roughly 1C difference between basement and main floor, and another 1C difference from main floor to top floor on average. This is from running fan full time during the day for circulation even when not calling for heat/cool.

Current temp readings:
21.5C Basement
22.5C Main Floor
23.0C Upstairs

ExtraSlow
07-07-2020, 08:19 AM
I wish I had this data from winter. I feel like it's more stable in heating season then cooling season. Although that's a guess.

rage2
07-07-2020, 08:26 AM
I wish I had this data from winter. I feel like it's more stable in heating season then cooling season. Although that's a guess.
The basement is way colder in the winter. I think I had a 5-6C swing between basement and 2nd floor back then, which is when I started running the fan 24/7. Something like 16C in basement and 22C upstairs. I'll have to check old data to confirm that.

Darell_n
07-07-2020, 09:45 AM
All of our homes in Alberta are built for heating only, with cooling in the summer being a compromise. 24/7 fan running will show better results in the winter than the summer.

brucebanner
07-07-2020, 09:54 AM
I have significant swings in my home as well.

Basement I would say is around 5° colder than main floor. With the upstairs being roughly 5° warmer than main main floor.

Central AC but I have a hell of a time trying to balance the house temperature. At least trying to cool upstairs more.

ExtraSlow
07-07-2020, 10:02 AM
wow, 10 degrees between basement and top floor! do you have any vents closed to try and focus the air to certain areas, or everything wide open?

88CRX
07-07-2020, 10:09 AM
Did you measure it as 10 degree swing? That seems crazy to be that far off.

We usually see 2d from basement to main and then 1-3d from main to upper. 3d to the SW facing bonus room with lots of windows and 1d on east facing bedrooms. Can usually equalize main to upper with running the furnace fan or HRV for an hour or two.

rage2
07-07-2020, 10:18 AM
Did you measure it as 10 degree swing? That seems crazy to be that far off.

We usually see 2d from basement to main and then 1-3d from main to upper. 3d to the SW facing bonus room with lots of windows and 1d on east facing bedrooms. Can usually equalize main to upper with running the furnace fan or HRV for an hour or two.
It's not unheard of if you have a lot of windows.

I'd say 30% my fix was from running the fan at low speeds through the day. The other 70% was programming my blinds for Morning, Noon and Afternoon so that the house never gets direct sunlight, just indirect lighting and only if the room is occupied or set to previous state.

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These little automations saved me so much money.

88CRX
07-07-2020, 10:25 AM
Yea good call.

Are people leaving their blinds up all summer? That is equally crazy. Lock that shit down first thing in the morning!

The_Rural_Juror
07-07-2020, 10:28 AM
What app are you using for those data points, Mr ES?

brucebanner
07-07-2020, 12:29 PM
wow, 10 degrees between basement and top floor! do you have any vents closed to try and focus the air to certain areas, or everything wide open?

Yes it's roughly that big of a difference. Numerous attempts at closing various vents trying to balance the temperature. I haven't found the sweet spot yet haha.

We spend close to zero time in the basement anyways but I'd like to have upstairs cooler without lowering the temperature any more.

kenny
07-07-2020, 12:55 PM
Roughly 1C difference between basement and main floor, and another 1C difference from main floor to top floor on average. This is from running fan full time during the day for circulation even when not calling for heat/cool.

Current temp readings:
21.5C Basement
22.5C Main Floor
23.0C Upstairs

My main/upstairs is same as yours, except basement is 19.5C (undeveloped). In winter the difference is much higher since I don't heat my basement unless there is motion down there.

?????
07-07-2020, 01:02 PM
Today is a good day since its overcast. I don't have A/C.

Basement - 20
Main - 21.5
Upper - 22
Even the garage is at 20.5

ExtraSlow
07-09-2020, 07:56 PM
Well, I think part of my issue was where the sensors were located. Moved em around abdn now main and upper floor are tracking much closer. AC turn on today about 5pm.
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The_Penguin
07-09-2020, 08:37 PM
Here's my last 30 days. Trying to plan ahead with opening/closing windows, have not used the AC much so far.
Bedroom is on 2nd floor.

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88CRX
07-09-2020, 09:45 PM
Speaking of opening windows got the house (main and upper floors) down to 15 degrees this morning. Might have even kicked the furnace on by accident lol