Furnace cycling too much?
#1
11-22-18, 06:42 PM
Furnace cycling too much?
Just bought a fixer upper. 1,100 sq feet of drafty windows and no insulation and some exterior walls which are partially insulated, but not sheetrocked yet... Its 10 degrees f and windy. Heat set at 60. Furnace turning on every 15 mins. Running for 9 mins. Shutting off than restarting in 6 mins. House feels cold when furnace stops. How do i know if its cycling to often, or just keeping up with the cold? Windows ordered and insulating has begun.
#2
11-22-18, 08:31 PM
Group Moderator
Four times in one hour is not excessive cycling with high heat loss.
Once you get the insulation and windows addressed the running time and fuel saved should improve.
Once you get the insulation and windows addressed the running time and fuel saved should improve.
#3
11-22-18, 08:58 PM
Member
With it set to 60, it will feel cold when the furnace shuts off.
Try 68. Once retrofit work is done (assuming u're going to insulate and air seal more), radiant heat loss will be lower, which should help.
Furnace cycles will be shorter.
Your furnace is probably large for the house* as is and will be even more oversized when you're done. Downsizing and going 2-stage can improve comfort.
You get consistent heat instead of a short blast of hot air.
*80 to 100k btu/hr output may have been common 40+ years ago for a house of this size. A 40 or 60k btu condensing furnace can probably do the job. Have a load calculation done to size if/when u change the furnace.
Try 68. Once retrofit work is done (assuming u're going to insulate and air seal more), radiant heat loss will be lower, which should help.
Furnace cycles will be shorter.
Your furnace is probably large for the house* as is and will be even more oversized when you're done. Downsizing and going 2-stage can improve comfort.
You get consistent heat instead of a short blast of hot air.
*80 to 100k btu/hr output may have been common 40+ years ago for a house of this size. A 40 or 60k btu condensing furnace can probably do the job. Have a load calculation done to size if/when u change the furnace.
#4
11-22-18, 10:56 PM
Thanks. I believe it is 76,500 btus. Furnace isnt to old, sticker says 92.1 efficiency. I didnt include model as i can't get panel open. I changed air filter as several sites suggested that could be problem. I will be insulating starting in 20 days when i retire to the house. Windows are ordered. Thanks for input..
#5
11-23-18, 05:04 AM
You need to insulate all exterior walls to compliment the new window addition or you will still have cold drafts. I am assuming the interior window trim is or will be removed for the new window install so this is a good time to insulate. In the meantime, I would install plastic sheathing on the exterior of the building for quick draft relief and allow the move into retirement to be enjoyable. When the windows come, just cut a hole in the plastic for the window and attach cut edges. Happy retirement.
#6
11-24-18, 04:21 PM
Thanks
I appreciate responses. I didnt budget for new furnace as the hvac company that services it said its in good condition. I am an insulation fool. I've rehabbed 5 houses and add as much insulation as i can ( without compressing of course). We are pulling the walls and giving rock woola try. I will insulate around windows of course...
#7
11-25-18, 11:01 PM
Member
That furnace will likely have even shorter cycles once the job is complete, but it should be more comfortable when off.
You'll just be stuck with it. In most of the us a well insulated house of the size won't need more than like 40k btu input, maybe up to 60k is okay if it's a bungalow.
If the thermostat is satisfying and it's not cycling off the burners during a call for heat, the filter won't have much of an impact.
You'll just be stuck with it. In most of the us a well insulated house of the size won't need more than like 40k btu input, maybe up to 60k is okay if it's a bungalow.
If the thermostat is satisfying and it's not cycling off the burners during a call for heat, the filter won't have much of an impact.
