Heating small cottage

Users who are viewing this thread

Port

New Member
Messages
1
Reaction score
0
Points
0
Location
CA
Great thread. And to piggy back a bit on the topic of mini-splits, I am curious about how much condensate to expect from the outdoor unit.

Specifically, if the outdoor unit were mounted to an equipment curb on a flat roof, is it worth it to pipe away the condensate, or fine to just let it drain onto the roof surface and make its way to the downspout? In my example the climate is rarely freezing, but I am interested in general.
 

Dana

In the trades
Messages
7,889
Reaction score
509
Points
113
Location
01609
In a CA climate (assuming you don't live at 8000' of altitude) it's fine to just let drip onto the roof. The amount of condensate (or melted defrost) you get will vary by the actual outdoor temperature & humidity. I have relatives in the foggy-dew Puget Sound region of WA that probably get several times the amount of condensate/remelt that you would anywhere in CA (due to the lower outdoor temp & higher humidity, and the higher/longer heating duty cycles) who just let it drip onto the ground next to the foundation without need to re-direct it.

You'll still get frost on the coils in CA, usually starting when the outdoor temps are in the mid-40s, but defrost cycles are brief & efficient. You get more frost + remelt when it's 40F and foggy than when it's 25F and sunny, due to the dramatically higher moisture content of the air under the warmer but wetter air condition. Any time the coil temp is 10F lower than the outdoor dew point and the duty cycle on the unit is high the condensation/frost rates pick up. Most of the time in heating mode the coil temp will be more than 10F cooler than the outdoor temp, for efficient heat exchange across the coil. Both the compressor speed and blower speed are continuously variable, and controlled to deliver the required amount of heat with maximum efficiency (the algorithms for the controls are proprietary to the manufacturer.) Efficiency is pretty high when it's condensing & frosting, despite having to periodically defrost, since the both the heat of vaporization & heat of fusion of the water is gained by the coil, and only part of the heat of fusion is given back (to get the frost to release and get blown out by the fan.)
 

Hunter01

New Member
Messages
27
Reaction score
0
Points
1
Location
Wisconsin
Well, the reply is somewhat embarassing, but here goes - On the lines (electrical) which connect the indoor and outdoor units, I crossed the power lines. Polarity matters in the ability of the two units to 'talk' to one another, so it's important to not just supply power to the indoor unit, but to have it hooked up correctly. Never too old to learn.
 

Dana

In the trades
Messages
7,889
Reaction score
509
Points
113
Location
01609
An easy mistake to make, and an error probably committed by "pros" on a daily basis (though the same pro probably doesn't screw that up more than once.) I'm sure it's something the tech support line hears every day.

I'd be curious to know how it makes out when the overnight temps are banging on -20F, and what the mid-winter heating bills are like compared to the propane-heating neighbors. I have pretty good second hand beta on how well the Mitsubishi H2i series do in cold weather, but nothing so far on the RLS2-H, since it is such a newly released model. Specs-wise it sure looks like a winner, and it's recent RLS2 ancestor a well known and highly efficient unit.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks