Comments on: What Happens to the Frost on My Heat Pump?

By: Joe

Joe — Thu, 11 Apr 2024 18:22:09 +0000

In reply to RoyC. Thanks for the thought provoking reply. I can see that the dew point will drop as some of the vapor condenses. Depending on many factors you could get condensation at the inlet but none at the outlet.

By: RoyC

RoyC — Thu, 11 Apr 2024 14:46:15 +0000

Joe, not all of the water in the air that passes through the coil will condense. The leaving air cannot have a dewpoint that is below the lowest surface temperature of the coil.

By: Joe

Joe — Wed, 10 Apr 2024 15:54:46 +0000

In reply to Cindi.

There is no one answer. It depends on how much moisture is in the air.
Chances are your outdoor exchanger is below the dew point so all of the water in the air that pumps through it will condense.
Good news..the state change gives more heat.
Bad news it can freeze which is the main focus of this discussion.

By: Cindi

Cindi — Wed, 10 Apr 2024 03:30:07 +0000

In reply to Rj. Yes but do you know about how much water you should expect to get if things are running normally?

By: Cindi

Cindi — Wed, 10 Apr 2024 03:28:26 +0000

In reply to rjp. How does that work?

By: Rj

Rj — Thu, 04 Apr 2024 18:49:29 +0000

In reply to Cindi. In extreme cold you need pan heaters to keep the melted frost from the coils from freezing again in the bottom. There are no photos. Watch the video, the text above is just repeating the video explanation.

By: Cindi

Cindi — Thu, 04 Apr 2024 17:23:47 +0000

Doesn’t seem to be any photos?
I know you live in the south but it’s amazing how little you see this. I’m in Idaho and we have to have heaters to melt the frost all winter, and it generates gallons of water a day. Is that typical for splits in cold climates? Mine is a Daikin VRV Life and I’ve been trying to figure out if that’s normal or not.

By: Michael Ramsay

Michael Ramsay — Sat, 09 Mar 2024 10:34:55 +0000

I live in southern Ontario and while many think it is very cold here, the fact is that we spend much of the winter not too far from 0C (32F). As such, how well heat pumps handle defrost is a significant part of the overall determination of heating efficiency. I think that much more attention should be given to how heat pumps deal with frost. We use a 2 ton York single speed heat pump with 15 kw of strip heaters as our main heat source. I recently added a Senville (Midea) 12k minisplit in the basement. I routinely monitor all electrical inputs and equipment temperatures which are continuous recorded and stored for analysis. You learn a lot about how these things work when you see the data. The York as very predicable demand based defrost that is easy to understand. It is certainly not perfect and in some conditions can get ‘behind’ causing long periods of low efficiency (the 8 minute max defrost time is just not long enough) The minisplit has a mind of its own and what looks like very poor defrost logic. In certain conditions it defrost every 100 minutes frost or not. This seems very unusual for modern equipment. My point is that while defrost performance can be a significant component of heat pump performance, I do see any data on the subject. Why not test all heat pumps at 0C 100%RH?

By: Robert Adams

Robert Adams — Thu, 29 Feb 2024 23:38:25 +0000

In reply to rjp. Hot gas is really old tech. It's been in every ice machine for many decades. Most cheap import minisplits now use it as well. Far better than a typical reversing valve and actually a more simple system.

By: Creditdocatl

Creditdocatl — Thu, 29 Feb 2024 21:05:38 +0000

In reply to RoyC. If you’re using a Mitsubishi controller advanced settings thermo off, or maybe continuous fan off it’ll stop the blower once set point has been met or in defrost.