Most efficient way to dehumidify home

I live in a bungalow in Atlantic Canada. The humidity levels in my home for 4 months of the year are high. I am getting a ductless minisplit installed. I am going to get am indoor unit upstairs and what I am wondering is this... should I also take the opportunity to get an indoor unit installed in the basement? I have electric baseboards to heat the basement in the colder months and I run a cheap portable dehumidifier during the 4 months in the summer (which does't do a great job). I am also wondering if the minisplit will efficiently dehumidify the basement during those months or is it more efficient to purchase a better/higher quality dehumidifier for that purpose? Thanks for the help in advance.
 

begreen

Mooderator
Staff member
Nov 18, 2005
85,093
South Puget Sound, WA
Maybe look into a HW heat pump if the HW heater is aging and located in the basement.
 
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maple1

Minister of Fire
Sep 15, 2011
10,602
Nova Scotia
Mini-split all day long over any kind of conventional dehumidifier. And any kind of thermal electric heat. In our climate. I would at least run it by an installer for input, may or may not be site-specific things to deal with - if nothing major, would be a no-brainer for me.

And yes a heat pump water heater may be an idea, but that won't do anything for heating in the winter.
 

begreen

Mooderator
Staff member
Nov 18, 2005
85,093
South Puget Sound, WA
And yes a heat pump water heater may be an idea, but that won't do anything for heating in the winter.
It will be heating the domestic hot water in all seasons. Usually, dehumidification is only needed in summer.
 
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Woodspliter

Member
Jan 25, 2020
105
Maine
I put a mini split in my basement in hopes that it would dehumidify it does work ok but my basement is pretty cool all summer and my mini split only cools to 62 degrees so it doesn't run very often and doesn't keep a constant humidity so I use it more for heat. Something to consider
 

DBoon

Minister of Fire
Jan 14, 2009
1,196
Central NY
I put a mini split in my basement in hopes that it would dehumidify it does work ok but my basement is pretty cool all summer and my mini split only cools to 62 degrees so it doesn't run very often and doesn't keep a constant humidity so I use it more for heat. Something to consider
I'll second that a mini-split used in a basement level doesn't do an effective job of dehumidifying. I have a Mitsubishi mini-split and when used in dehumidify mode it will cool the space down quite a bit but not keep the humidity below 65 percent. I just use a portable dehumidifier and that is much more effective. At another house, I also had good luck with a heat pump water heater at dehumidifying a basement in the summer.
 

maple1

Minister of Fire
Sep 15, 2011
10,602
Nova Scotia
It will be heating the domestic hot water in all seasons. Usually, dehumidification is only needed in summer.
Well, yes, but he also mentioned baseboard electric heat, in a way I thought he was also exploring alternatives to. Maybe I was wrong on that.

Also, I'm not convinced splits are not good dehumidifiers. Our 2 Daikins keep our living levels super comfy, in dry mode, even when it's way humid outside. Granted we don't live in the basement, but don't do any other dehumidifying either.
 

brenndatomu

Minister of Fire
Aug 21, 2013
5,530
NE Ohio
Also, I'm not convinced splits are not good dehumidifiers. Our 2 Daikins keep our living levels super comfy, in dry mode, even when it's way humid outside. Granted we don't live in the basement, but don't do any other dehumidifying either.
Because basement temp is much cooler than what you keep your living space at...MS doesn't run enough to dry things out...same as with a central AC system that is oversized for the house...doesn't run long enough to dehumidify the space.
Our HPWH is doing a good job of keeping the basement dry this summer without running the dehumdifier at all...it did get a little "damp" while we were gone over the weekend, since there was no demand to make it run...dried right back out after everybody got their showers and laundry was started though. Easy enough to run the DH while you are gone if you travel a lot though, we don't, so no big deal...
 
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TradEddie

Minister of Fire
Jan 24, 2012
901
SE PA
Good air sealing will do more than any electrical solution.

Although I live in a warmer climate, I can attest that installing a HPWH in my basement eliminated any need for additional dehumidification. In your climate Winter temperatures in your basement might reduce the efficiency of the HPWH. It probably doesn't make sense to use baseboard heaters or a HP to warm the basement, then have a HPWH take that heat away again. How cold would your basement get in Winter if you didn't add local heat?

Do remember that raw %RH numbers are a terrible way to assess whether you really need dehumidification. The Internet is full of inaccurate and misleading information about humidity levels, usually with the intent to sell you something. Most warnings about mold are totally overblown. Do you have living space in your basement, are you storing valuable paperwork down there, or do you just need to make sure that tools don't rust or the walls don't sweat?

TE
 

EbS-P

Feeling the Heat
Jan 19, 2019
381
SE North Carolina
This spring we installed a heat pump water heater in the basement. Remember it needs a drain. Down here in the south it has helped. I still run two dehumidifiers dumping about a gallon and a half a day. Basement is a walkout about 1000 sq ft. Our HVAC does not have an air return for the basement. I think would help some. Basement humidity is all about moisture moving from the wet outside to the drier inside. Do you have gutters? Where do the downspouts drain too? What kind landscaping is near the house? It all matters some.
I don’t see any practical way to completely replace dedicated dehumidifiers. That said if you have an electric hot water heater and it needs replaced a heat pump unit is a no brainer. Will the mini split help of course. But once The basement is nice and cool moisture is still moving in but not being taken out.
I am considering a power vent fan that moves the basement air up to to main floor. My thoughts are these in the moves colder air to the warmer space and that’s a good thing in both summer and winter.
Just my thoughts.
Evan
 

TradEddie

Minister of Fire
Jan 24, 2012
901
SE PA
This spring we installed a heat pump water heater in the basement. Remember it needs a drain. Down here in the south it has helped. I still run two dehumidifiers dumping about a gallon and a half a day. Basement is a walkout about 1000 sq ft. Our HVAC does not have an air return for the basement. I think would help some. Basement humidity is all about moisture moving from the wet outside to the drier inside. Do you have gutters? Where do the downspouts drain too? What kind landscaping is near the house? It all matters some.
I don’t see any practical way to completely replace dedicated dehumidifiers. That said if you have an electric hot water heater and it needs replaced a heat pump unit is a no brainer. Will the mini split help of course. But once The basement is nice and cool moisture is still moving in but not being taken out.
I am considering a power vent fan that moves the basement air up to to main floor. My thoughts are these in the moves colder air to the warmer space and that’s a good thing in both summer and winter.
Just my thoughts.
Evan
I think two of your suggestions above might possibly end up being counter-productive. Natural stack effect makes a basement at lower pressure than the outdoor air, this creates the differential that draws air into the basement, the air cools down, becomes even more humid, possibly even condensing on cool walls. Having an HVAC return, or a separate fan drawing air upstairs out of the basement would only exacerbate that effect. I fully agree with the benefits of outdoor grading, working downspouts, adequately sized gutters, but those don't address humidity coming from outside air, especially in a Southern USA climate. Air sealing in the basement, and throughout the house will reduce that pressure differential, or at least reduce the ability of air to move indoors due to it.
On a related note, my HPWH has broken and the effect on my electric bill and basement humidity are significant. Unfortunately it appears that nobody wants to service a Geospring, refrigeration certified plumbers won't even return my calls.

TE
 

gzecc

Minister of Fire
Sep 24, 2008
4,709
NNJ
I would suggest looking into a Humidex or Breeze type system. These remove humid air by way of a fans and humidistat and get make up from the upstairs conditioned air. There are compromises with all solutions, so you need to evaluate your specific application.
 

jeanw

Feeling the Heat
Sep 23, 2008
346
ky
I would suggest looking into a Humidex or Breeze type system. These remove humid air by way of a fans and humidistat and get make up from the upstairs conditioned air. There are compromises with all solutions, so you need to evaluate your specific application.
I can't locate "the Breeze" manufacture so can order directly from them or like HD or Lower. . not keen on using EB
anyone know?
 

Woodspliter

Member
Jan 25, 2020
105
Maine
Look into a tjernlund x2d you can get then right on Amazon for 200 bucks. They go right in between the floor joints right though the sill. You can hook up ducts to it and reverse the air flow. That's what I'll be installing in my finished basement.
 

gzecc

Minister of Fire
Sep 24, 2008
4,709
NNJ
Go to the Humidex website. Follow from there.
 

fbelec

Minister of Fire
Nov 23, 2005
2,888
Massachusetts
bad thing about putting in a register between your basement and first floor is that will increase the load on the hvac. if you are going to install a mini split they do make them with a dehum mode and when installed use a smaller unit than you would in a normal above basement room and it will run longer