Frosty day in mini-split land..

Xringer · 12-31-11, 10:58 AM

It's been just above freezing since about 10PM last night..
This morning around 8AM, it rained a little.
It's been getting more humid since midnight.

I guess these are the prefect conditions for frost on the coils..

I noticed the power use was a little higher than normal for 33F.. (1KW continuously).
So, I took a look outside. Both coils were 80% covered with a layer of frost/ice.
The fan motors sounded labored.. But, we were still getting enough heat to keep the house at 21C..

The forecast is for light rain and low 40s this afternoon, I just shut them down for now..

Have to get out the Aux 1200w heater if we get chilly before the ice melts..

Ryland · 12-31-11, 05:07 PM

If one of these was installed where no one was paying attention to it what would happen in this condition?

Xringer · 12-31-11, 05:32 PM

The defrost mode would automatically kick in at some point.
I don't recall exactly how the controller knows about the frost, but it works..

Since both my Sanyos were still pushing out some good heat,
I can only assume the defrost cycle wasn't going to occur right away.

Note:
This model of Sanyo seems to have a power surge problem,
and Defrost mode is one of the events that will trigger a power surge.
I've installed electronic breakers to limit those surges.

I left both systems off for about two hours and saw some slow melting.
The forecast didn't pan out. It stayed in the mid 30s.
So, after the house got down to about 18C, I tried using the Dehumidifying Mode..
Worked like a charm. Didn't pull a big surge of power either.
I watched the indoor coils drop to freezing before shutting them down again.
A short time later, the ODU coils were 95% clear.. So, the heat was cranked back up..

I'm keeping track of likely 'frost-up' weather conditions..
I just might be able to use my new board, to set up an alarm system that can alert me of a pending frost-up..
http://ecorenovator.org/forum/applia...ontroller.html

The goal would be, to keep a really thick, or hard-to-remove layer of ice from building up.

The weather here in the Boston area can change very rapidly.
So, idea frost-up conditions might disappear, before the house started to cool..
But, running with 90% of the coils blocked, could result in excessive power use,
and extra wear to the ODU motors & compressors..

12-31-11, 10:58 AM	#1
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Frosty day in mini-split land.. It's been just above freezing since about 10PM last night.. This morning around 8AM, it rained a little. It's been getting more humid since midnight. I guess these are the prefect conditions for frost on the coils.. I noticed the power use was a little higher than normal for 33F.. (1KW continuously). So, I took a look outside. Both coils were 80% covered with a layer of frost/ice. The fan motors sounded labored.. But, we were still getting enough heat to keep the house at 21C.. The forecast is for light rain and low 40s this afternoon, I just shut them down for now.. Have to get out the Aux 1200w heater if we get chilly before the ice melts.. Attached Thumbnails __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

12-31-11, 05:32 PM	#3
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	The defrost mode would automatically kick in at some point. I don't recall exactly how the controller knows about the frost, but it works.. Since both my Sanyos were still pushing out some good heat, I can only assume the defrost cycle wasn't going to occur right away. Note: This model of Sanyo seems to have a power surge problem, and Defrost mode is one of the events that will trigger a power surge. I've installed electronic breakers to limit those surges. I left both systems off for about two hours and saw some slow melting. The forecast didn't pan out. It stayed in the mid 30s. So, after the house got down to about 18C, I tried using the Dehumidifying Mode.. Worked like a charm. Didn't pull a big surge of power either. I watched the indoor coils drop to freezing before shutting them down again. A short time later, the ODU coils were 95% clear.. So, the heat was cranked back up.. I'm keeping track of likely 'frost-up' weather conditions.. I just might be able to use my new board, to set up an alarm system that can alert me of a pending frost-up.. http://ecorenovator.org/forum/applia...ontroller.html The goal would be, to keep a really thick, or hard-to-remove layer of ice from building up. The weather here in the Boston area can change very rapidly. So, idea frost-up conditions might disappear, before the house started to cool.. But, running with 90% of the coils blocked, could result in excessive power use, and extra wear to the ODU motors & compressors.. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

12-31-11, 05:07 PM	#2
Ryland Master EcoRenovator Join Date: Mar 2009 Location: Western Wisconsin. Posts: 913 Thanks: 127 Thanked 82 Times in 71 Posts	If one of these was installed where no one was paying attention to it what would happen in this condition?