Santa Fe.

 

A couple of years ago, I bought a Carrier Ductless Mini Split system.

The two main features that sold me on it both turned out to be worthless.
The zoning is pretty ineffective, when one gets heat they all do and it varies fan speed to supply more heat to one space. However, each space still gets some heat.
That means the upstairs rooms have a "Sauna" mode if I run that heater.
I already beat that problem to death in another post, still not pleased though.

The second issue is humidity control. It claimed it could control humidity.
Well, it has a "dry" mode, and it does remove moisture.

But it does so by running the air conditioner and condensing water on the coils. <-- WHAT ?
That also ends up cooling the space it's running in.

Not only that but "Dry" and "Heat" are mutually exclusive, you can't run them both at once.
So that means even faster cooling.
It is also a colossal waste of energy to cool the space to dry it, then turn around and heat it up again.

The problem is that I live in Seattle.

We don't have humid summers, we have humid winters.
While many of you run gas heat and have to add a humidifier,
I deal with RH of 80% at times when it rains for weeks on ends.

My current "solution" is a stand alone dehumidifier.
It's noisy and only does part of the house.
The one good thing is that the entire unit is indoors, so the heat this process generates also heats the room.

I'd like to explore options for the entire house.
It appears that since I don't have ducts, there really are no good options.

I know I can't do anything with the mini split system, it is what it is,
but are there any good options for homes without ductwork?

Barring that, any suggestions on best/quietest stand alone dehumidifiers?

You have handcuffed your hands-behind-your-back by yourself.
The KEY to freeing yourself
is to use simplified duct work for the dehumidifier supply air.

I don't have a specific duct arrangement nor specific NEW Dehumidifier
GIVEN lack of ANY information about your residence.

 

Easy to add a small whole house dehumidifier to conditioning ducts. In your case, are there any? If no, I would by finding a space that you could locate the dehumidifier in a closet or laundry room with small supply duct system to the key areas you are concerned about. The return to the dehumidifier can be a duct through the laundry room wall to the dehumidifier. Locate the dehumidistat on the house side of the laundry room. The dry air will be supplied to the key parts of the home and find its way back of the home via door undercuts.
In homes in your region, indoor air that is damp when the outdoor dew point is below a 50^F dew point are not getting enough fresh air to purge indoor pollutants, including moisture from the occupants. If my house, I would include a 6" fresh air inlet to assure fresh air change when occupied. A fresh air change in 4-5 hours of <50^F outdoor dew point air will reduce the indoor humidity, indoor pollutants, and improve the oxygen content in a heated home to <50%RH.
You could try operating a good exhaust fan during weather with <50^F outdoor dew point. Or measure the CO2 levels with meter. During cold weather, heating the room also reduces the %RH in the space.

CO2 meters.com
<$100

You had a suggestion on good dehumidifier, Santa Fe. The Ultra-Aire is similar but setup with 8" duct collars.

Keep us posted.
Regards Teddy Bear

 

Easy to add a small whole house dehumidifier to conditioning ducts. In your case, are there any?

No ducts and no reasonable way to retrofit/install them.

If no, I would by finding a space that you could locate the dehumidifier in a closet or laundry room

That could be an option. I'll have to give it some thought. Was considering installing a tankless water heater. That could make room for a unit where the water heater is now.

In homes in your region, indoor air that is damp when the outdoor dew point is below a 50^F dew point are not getting enough fresh air to purge indoor pollutants, including moisture from the occupants.

The house is over 30 years old, and no longer air tight by any means. When new, we had an exhaust fan on a timer that ran for an hour each day to ensure fresh air. If it didn't run, we'd get condensation on the windows. That's no longer an issue. The problem is that the outside air is also very humid. This week for example, it rained 5 days straight. Outside humidity is 80%. Indoor humidity is 60%. No ventilation issues today, doors and windows are open.

You could try operating a good exhaust fan during weather with <50^F outdoor dew point.

I have, and use, one in my bathroom, where nice long hot showers generate much of the moisture. It's on a timer than can run up to 30 minutes.

During cold weather, heating the room also reduces the %RH in the space.

Yes, the same air, when heated, will have lower RH. That's why it's 60% inside when it's 85% outside. But I prefer it to be lower, both for comfort and mold reduction, a continual battle in Seattle.