Dehumidifiers

[M_Six]

Anyone have a dehumidifier that is not an a/c system but is tied into the HVAC system?

Our walkout basement has just a furnace. There was a heat pump system there originally, but then it failed a few years ago, we had them replace it with just a gas furnace as we hardly ever ran the a/c. And even with the furnace, it's only in use maybe four months of the year. The basement has been fine with just the furnace until this year. This summer was exceptionally humid and we've been noticing some minor (as of now) mildew problems in the basement. I'm thinking of having the HVAC folks install a dry (desiccant) system into our existing system. But I could also go cheaper and just get a standard refrigerant based system and have it drain into an existing floor drain. The issue there is that would have to be in the furnace room, which is also where the litter boxes for our cats are. I'm worried a system like that would not work well in a room that has litter dust in even small amounts.

Looking for suggestions, pointers, and watch-outs.

[2000cs]

We have had many of those free-standing dehumidifiers over the years. The best set up is with a drain as you mentioned; second best is using a scavenger pump and pumping into a sink or other drain line.

Ours were always in the unfinished part of our basement because they do sometimes leak and there is the fan noise. We didn’t have any problem but we also didn’t have a cat.

If the floor is carpeted make sure there is clearance for air to come into the unit from below (if it requires it), otherwise you’ll want to put it on a piece of plywood. There really isn’t much more to those units.

[M_Six]

Originally Posted by 2000cs

We have had many of those free-standing dehumidifiers over the years. The best set up is with a drain as you mentioned; second best is using a scavenger pump and pumping into a sink or other drain line.

Ours were always in the unfinished part of our basement because they do sometimes leak and there is the fan noise. We didn’t have any problem but we also didn’t have a cat.

If the floor is carpeted make sure there is clearance for air to come into the unit from below (if it requires it), otherwise you’ll want to put it on a piece of plywood. There really isn’t much more to those units.

Thanks. The floor is covered in vinyl, so that shouldn't be an issue. And I'd get one with a timer so it wouldn't run at night. I found one with an internal filter and I'm thinking a simple foam pre-filter would negate the dust issue. But I'd really like a built-in system that works with the existing heating system. That would no doubt get into 4 figures, but if it's set it and forget it, I'd be ok with that.

[2000cs]

The stand-alone ones are pretty much set-it-and-forget-it, as long as you have the drain properly set up (which you’ll also need for a permanent one). I recommend one with a humidity setting and then let it run as needed. Most are probably like that.

There is a product at Lowes/HD/BBB that helps get rid of moisture also. Damprid I think. You can hang them in a closet, etc. We used those for a while until we figured out we had a leak behind a finished wall, so opened things up to patch the foundation wall. They are effective but really too expensive to be a permanent solution for a big area. Would have to check cat safety for those too, just to be sure.

Which gets to the key issue: how is your space getting moist? If it is just colder there and you’re getting some condensation from your household air, maybe there are flow adjustments your HVAC folks can make to balance that better, or set your thermostat fan control to “circulate”. If there is a leak somewhere, like we had, you’ll want to address that properly of course. We always had some seeping and our house was old enough that the basement floor didn’t have a vapor barrier. Sometimes you have to use these mitigations instead of fixing the underlying problem due to cost, but it is always worthwhile to know what the cause is.

[M_Six]

I'm not sure why we seem to be having these minor mildew issues other than it was a very humid summer. The systems in the house have been the same for several years, but it's just this year that we're seeing these scattered mildew issues. This is not a widespread problem, but here and there we find a book with minor mildew or for instance we have a folding panel "wall" that we got when Wifey had to do a bunch of Zoom meetings and we wanted to hide some of the background. It's wood and today I saw it has some minor mildew spots on it. I could easily wipe them away, but the fact that they are even there concerns me. I feel like this is the beginning of a problem and I want to nip it in the bud.

[omasou]

I bought an Aprilaire 1850. They have different sizes based on the size of your house. It is designed to hook into the HVAC but I use it free standing.

Though it is in the basement it eventually will lower the humidity in the entire house without attaching to the HVAC.

[M_Six]

Originally Posted by omasou

I bought an Aprilaire 1850. They have different sizes based on the size of your house. It is designed to hook into the HVAC but I use it free standing.

Though it in the basement it eventually will lower the humidity in the entire house without attaching to the HVAC.

I was looking at something like that. No outside compressor needed. Do you vent the moist air outside or not?

[omasou]

Originally Posted by M_Six

I was looking at something like that. No outside compressor needed. Do you vent the moist air outside or not?

The entire unit is self contained. There is no moist air. The air blows out the top after the moisture is condensed. The condensate line is attached to the same condensate lines for the HVAC, which dumps into the sump.

EDIT: Missed the part about the liter box. The unit has a washable filter and it's really just a big box w/the compressor and condenser, I doubt it will clogged from a litter box. A woodworking shop maybe.

[Lady Jane]

Good morning Mark!

This is what I use for the basement but only during the Summer months. I like to keep the humidity level at around 40% because the basement is where I keep my music room and home theater.


The unit that I use is good for 1200 sq/Ft. I have the option to run a hose to a drain but esthetically speaking, I just empty the bucket as required.



Attachment 2722385

[BMWILUVU]

My dehumidifiers last at most 2 years. Does anyone else experience this or is it just my luck with this equipment?

[omasou]

Originally Posted by BMWILUVU

My dehumidifiers last at most 2 years. Does anyone else experience this or is it just my luck with this equipment?

My first Aprilaire whole house dehumidifier lasted 11 years.

Originally Posted by BMWILUVU

My dehumidifiers last at most 2 years. Does anyone else experience this or is it just my luck with this equipment?

Yup. I've had a few Aprilaire cheapie standalone units burn out after a couple years.

I've had fantastic luck with the the following though:
This one I have in a ~2500 sq ft basement that's rather humid. Works at least 8 months out of the year for the last 3 years w/ no problem:
https://smile.amazon.com/gp/product/...e?ie=UTF8&th=1

I have this one running in a VERY humid 3 bedroom condo @ the beach and it's done a fantastic job over the last 2+ years:
https://www.amazon.com/gp/product/B0...9CYHA505X&th=1

OP as mentioned, the key here is to set it to drain into a sump, bathtub, etc. so that you don't have to worry about dumping it out every so often. I wouldn't worry at all about what little dust the cats kick up...you'll likely have "average" amounts of dust be more of a concern than anything else.

The next house I build will definitely have a whole house system in place, but your scenario sounds very light duty, so I'd just go the standalone route for now and see how it works out over the next couple years. Definitely go with larger units (like linked above) as they've been more reliable in my experience.

[Kolyan2k]

Originally Posted by omasou

I bought an Aprilaire 1850. They have different sizes based on the size of your house. It is designed to hook into the HVAC but I use it free standing.

Though it is in the basement it eventually will lower the humidity in the entire house without attaching to the HVAC.

I have 70 pints dehumidifier in basement and it doesn't seem to lower humidity in entire house (2500 sqft)

I have 2 hvac systems 1st for basement + 1st floor and 2nd system for 2nd floor. I was thinking maybe good idea to have it built in for 1st hvac system, but am worried that it will not dehumidify 2nd floor.

[omasou]

Originally Posted by Kolyan2k

I have 70 pints dehumidifier in basement and it doesn't seem to lower humidity in entire house (2500 sqft)

I have 2 hvac systems 1st for basement + 1st floor and 2nd system for 2nd floor. I was thinking maybe good idea to have it built in for 1st hvac system, but am worried that it will not dehumidify 2nd floor.

I have similar setup. HVAC for 1st and other for second, basement unfinished as of now.

House is normal at ~45% in the summer and too dry in winter. I really need to add some humidifiers to HVAC.

If you in-line to your basement / 1st floor it should also remove humidity on 2nd. If I remember correctly it is possible to in-line to both but gets a bit complicated.

[M_Six]

I spoke with the contractor who has done our HVAC systems and he thinks we might be able to duct some return air from the basement into the upstairs a/c system so the more humid air from the basement will pass through the dehumidifier in the a/c system. I'm not sure there's a pathway for that ducting, though. We'll have to do some investigating.

I may buy one of the Homelabs stand-alones in the meantime. A couple hundred bucks isn't bad even if it turns out to be a temporary thing.

[Kolyan2k]

Originally Posted by omasou

I have similar setup. HVAC for 1st and other for second, basement unfinished as of now.

House is normal at ~45% in the summer and too dry in winter. I really need to add some humidifiers to HVAC.

If you in-line to your basement / 1st floor it should also remove humidity on 2nd. If I remember correctly it is possible to in-line to both but gets a bit complicated.

Maybe it will be perfect than. I run ERV on 2nd floor. And I can run Ultra Aire dehumidifier with fresh air intake on 1st. Perhaps project for next year. In winter I run room humidefiers in bedrooms at night

[omasou]

Originally Posted by Kolyan2k

Maybe it will be perfect than. I run ERV on 2nd floor. And I can run Ultra Aire dehumidifier with fresh air intake on 1st. Perhaps project for next year. In winter I run room humidefiers in bedrooms at night

Here's a start but you'll need to search to see how it's actually ducted and wired.

Do Aprilaire Dehumidifiers offer zoned dehumidification?
Aprilaire dehumidifiers models 1750A, 1770A, 1830, 1850, 1850W, 1852, 1870, E080, E100, and E130 offer zoned dehumidification through an internal or external control. Your heating and cooling installer will know the proper wiring for this application.

Originally Posted by Kolyan2k

In winter I run room humidefiers in bedrooms at night

I went from standalone bedroom systems, to passive whole house units. Then ripped those passive units out and went with steam whole house units instead. They're AMAZING! Anything less is just a bandaid IMO:
https://smile.amazon.com/Aprilaire-8...39&sr=8-6&th=1

[omasou]

Originally Posted by FCobra94

I went from standalone bedroom systems, to passive whole house units. Then ripped those passive units out and went with steam whole house units instead. They're AMAZING! Anything less is just a bandaid IMO:
https://smile.amazon.com/Aprilaire-8...39&sr=8-6&th=1

I saw those last year but thought they were way more expensive. My only challenge is can I buy one to use w/both HVACs?

Thanks for reminding me about them, I need to research them this year.

[omasou]

Originally Posted by M_Six

I spoke with the contractor who has done our HVAC systems and he thinks we might be able to duct some return air from the basement into the upstairs a/c system so the more humid air from the basement will pass through the dehumidifier in the a/c system. I'm not sure there's a pathway for that ducting, though. We'll have to do some investigating.

I may buy one of the Homelabs stand-alones in the meantime. A couple hundred bucks isn't bad even if it turns out to be a temporary thing.

May want to run a radon test. I have a mitigation system for radon that pulls the air out from under the slab and exhausts it outside but concern about circulating radon no matter how little is the thing that stops me from ducting the basement w/one of the other floors.

[Kolyan2k]

Originally Posted by FCobra94

I went from standalone bedroom systems, to passive whole house units. Then ripped those passive units out and went with steam whole house units instead. They're AMAZING! Anything less is just a bandaid IMO:
https://smile.amazon.com/Aprilaire-8...39&sr=8-6&th=1

I have baseboard heat

Originally Posted by omasou

I saw those last year but thought they were way more expensive. My only challenge is can I buy one to use w/both HVACs?

The steam humidifier unit itself has to be like ~3 feet away from the chosen air handler, so no, it won't run steam to both air handlers, but depending on the size/layout of the house, you might be able to get away with just using 1 unit altogether.

I have a ~3500 sq ft house which has separate heat pumps/air handlers for upstairs/downstairs. I was able to get away with using just 1 Aprilaire steam humidifier for the whole house (downstairs). When setting the controller past 3/7 I was getting condensation on windows, etc. given how much steam it was pumping out, so it's definitely a very strong/capable unit when run @ 240V for that size structure.

In contrast, I also have a 10K sq ft house where I started with 1 unit (downstairs) and when cranked to 7/7 it does well for the basement/first floor, but wasn't reaching the top 2 levels. Added a second steam unit last winter on the upstairs air handler as well and now the whole house is covered 100%.

The neat thing about the controller on these is that it comes with an outdoor temp sensor that helps automatically adjust the level of moisture necessary inside given the exact ambient temp outside. This saves you from having to make constant adjustments to the unit itself as the outdoor temp changes, which keeps the unit from putting too much moisture in the air inside the house, etc. Simple to install as well; I utilized 2 unused wires that ran to the heat pump from the air handler and installed the temp sensor on the plastic fan shroud of the heat pump itself.