ERV/HRV for basement

[carwashguy]

Currently about half of my walkout basement is finished and the other half is my shop area, laundry, forces air furnace ,water heater and some storage.  I want to add a bathroom down there but I know i need to deal with the humidity before i get too deep into the project.  I was considering a HRV or ERV  over a whole house dehumidifier. (NOTE  I wrote "whole house Dehumidifier"  but this is only going to be for the 1100 sqft basement)

The current room is about 16x22 with a 5x3 window at one end.   Ill be adding a bathroom/laundry room (about 8x10) with a walk in storage closet.  There will be no windows in these new rooms but the bathroom will have a regular vent fan.

Can anyone advise me on what type (HRV vs ERV) that I should be using.    The more research I do the more unsure I am on what unit to use

[woodworker2000]

I believe you want an ERV if you intend to remove humidity from the air; however from my read of this article: HRV or ERV  it seems that your climate determines which of the two should be installed.

[srv52761]

I think you may be better off with a stand alone dehumidifier. I am assuming your basement is relatively well sealed, and you have addressed any issues that are introducing water vapor.

We can easily keep humidity levels to 40%-45% in a 900sq.ft. classroom with a 40 pint dehumidifier.

[jteneyck]

I think you may be better off with a stand alone dehumidifier.  I am assuming your basement is relatively well sealed, and you have addressed any issues that are introducing water vapor.

We can easily keep humidity levels to 40%-45% in a 900sq.ft. classroom with a 40 pint dehumidifier.

I agree.  I use a stand alone 40 pt dehumidifier in my basement shop which is about 25 x 35'.   It has no trouble keeping the RH between 50 and 60%.  Once the envelop is pretty tight, it doesn't take a lot.  

John

[blackhat]

Is this space not already inside the thermal envelope of the home?  The central heating/cooling unit doesn't serve this space?  Why does the space need additional dehumidification?  When does it need dehumidification?  

Keep in mind that both those systems rely on dry air from outside replacing moist air from inside to drop the RH of the space. If outside air is 65 degrees and 70% RH, you won't get inside below 70%.

[carwashguy]

Is this space not already inside the thermal envelope of the home?  The central heating/cooling unit doesn't serve this space?  Why does the space need additional dehumidification?  When does it need dehumidification?  

The finished area is connected to the heating cooling system but the heat is somewhat inadequate for the area and I close off the vents when I run the AC.  I intend on adding an additional supply to the area as well as a new supply in the bathroom.   There is a 12" return from the basement into the furnace that was added when furnace was replaced 12 years ago.  
My concern is that a bathroom and storage closet with no way to get outside air is going to become humid even with a standard bathroom fan.
The basement does get humid in the seasons that have no heating cooling.  I did have a dehumidifier years ago that worked well but it was part of a recall and was never replaced.  

I thought the a HRV would be the way to go but I think, because of your questions, that a dehumidifier might be adequate.  Do you have any recommendations for a multi-room dehumidifier?

[blackhat]

I can't give you a brand specific recommendation but I would place the unit where there is good airflow from the heating and cooling system, a large return air grille nearby would be best.

[srv52761]

I can't give you a brand specific recommendation but I would place the unit where there is good airflow from the heating and cooling system, a large return air grille nearby would be best.

Mmm... generally when you give advice I feel like I can take it to the bank.  But I don't understand this one. I was thinking if  he placed it where  he had air flow from the hvac that the A/C would already be supplying low humidity air and the dehumidifier would not be used to its greatest  advantage.  
   
Also, he was  concerned about the areas where the air flow was poor. 

Finally, if next to a return vent, the dehumidified air will be sucked through the A/C coils,  which would be easier on the A/C, but at a cost of having less total water vapor removed from the A/C and dehumidifier together if they didn't share as much of the same air so soon.

Just my thoughts, but I've been wrong before... lots of times.

[blackhat]

No worries.  He had mentioned that he had plans and capacity for air circulation in the proposed upgrade so I let that slide.  The advantage to placing it near a return grille is that the furnace fan can run on low speed circulate all the time and share the drier air with the rest of the house if desired. That's an elaboration I should have made in my earlier post.