air exchanger

[bucketmouth64]

My gf has a programmable pad attached to furnace that controls the fan/air exchanger. It can be set to continuous or off/on for whatever you set it at. It is a two-level townhome; wondering what is the best setting? How long does it take to change the air so to speak. Right now I have it set at off/on every 30 minutes.

[spearchucker]

More often in the winter. In humid weather, you will be just drawing in moist air and fighting your A/C.

[BoxMN]

We have one in new construction (2 yo, at cabin) and we set it at 10% when we are not there, and 30% when we are, in winter. Just bump it up to 90% or so when cooking, lots of people, etc. In summer I don't turn it off, just back to 10% and leave it there all summer. I am still finding the sweet spot for winter, but adjusting a bit as needed works well. Ours is just a single "button" that adjusts the level % up and down.

[bucketmouth64]

The control is in minutes. I could be wrong about it being an air exchanger; never seen one set up. I think the control pad just controls the furnace fan. The temp. difference upstairs/mainfloor is noticeably different, that is why I increased the fan time on/off to 30 minutes to try and equalize the temperature difference.

[BoxMN]

Oh, I should have said, the % is in "time running", so it would match your minutes - i.e. 100% equals all the time. (Variable speed furnace fans use little energy and keep theh ouse from having cool/hot spots. We have variable at home, and it is great for keeping temp equal all over, at cabin we don't, but I just turn on fan, to "On" instead of "auto" at times to move it around if needed.)

If you want to equalize the temp, then have your furnace fan run all the time, that will blow it around through all vents. The air exchanger is just for exchanging "house" air with "fresh" air.

[spearchucker]

Our air exchanger has a humidistat that will turn it on when humidity is too high and it also has on demand buttons in the bathrooms (turn on when taking a shower to remove humidity). The minute control you are seeing is how long it will run for when you push the on demand button. Mine will run for 20 minutes when the on-demand button is pressed. Some air exchangers are connected with the furnace fan and some are separate. It depends on how they were wired.

[bucketmouth64]

Oh, I should have said, the % is in "time running", so it would match your minutes - i.e. 100% equals all the time. (Variable speed furnace fans use little energy and keep theh ouse from having cool/hot spots. We have variable at home, and it is great for keeping temp equal all over, at cabin we don't, but I just turn on fan, to "On" instead of "auto" at times to move it around if needed.)

If you want to equalize the temp, then have your furnace fan run all the time, that will blow it around through all vents. The air exchanger is just for exchanging "house" air with "fresh" air.

Thanks Box. I'll let her know so she will have to decide if she wants to pay the electric cost to have it on 24/7 or have it on/off every 30 minutes.

On another note, how woould a dehumidifier work on a second level? I know they usually are in the basement, but I was wondering if anyone has used them in upper levels if there is no basement.

[spearchucker]

The dehumidification only really works in the winter where you are drawing in drier air from outside and pushing out inside air.

Also your air exchanger may or may not be running your furnace fine as I stated earlier, so the 30 minute run may not be actually circulating air through the whole house with the furnace fan.

[delcecchi]

The trouble with a dehumidifier is that it warms the air also. So it is not what you would want in summer, generally speaking. In winter, the air is dry already so not a problem.

People use them in basements because they tend to be cool and damp. making them somewhat warmer and dry is a good trade off.

If you want a dehumidifier for comfort on upper level in summer, a small AC of some kind might be better.

[MERC70]

All,

I am looking into an air exchanger. Could you give a Make or Brand to go by?

Thanks...

[spearchucker]

The trouble with a dehumidifier is that it warms the air also. So it is not what you would want in summer, generally speaking. In winter, the air is dry already so not a problem.

People use them in basements because they tend to be cool and damp. making them somewhat warmer and dry is a good trade off.

If you want a dehumidifier for comfort on upper level in summer, a small AC of some kind might be better.

We are talking air exchangers not dehumidifiers. Air exchangers only exchange inside air with outside air. They are a "passive" dehumidifier and don't rely on a compressor so no heat is released.

[delcecchi]

Did you read the last paragraph of Bucketmouth64's post?

"On another note, how woould a dehumidifier work on a second level? I know they usually are in the basement, but I was wondering if anyone has used them in upper levels if there is no basement."

[spearchucker]

Did you read the last paragraph of Bucketmouth64's post?

"On another note, how woould a dehumidifier work on a second level? I know they usually are in the basement, but I was wondering if anyone has used them in upper levels if there is no basement."

Yes I did. Did you read the entire thread? He is asking about dehumidification controls for the air exchanger.

Air exchangers can be controlled by a humidistat. This is only really useful in the winter, you usually shut the humidistat control off in warmer weather because it won't work. Air exchangers remove humidity by exchanging dryer outside air with moister inside air. They don't actively remove humidity like a standard dehumidifier. They work on every level because their are usually air exhaust intakes throughout the house on every level that suck out the stale air to the outside and replace it with outside air drawn into the cold air returns of your ductwork.

This doesn't work well in the summer because the outside air is generally just as humid or more humid than the inside air. They work good in the winter to keep moisture from building up on windows in cold weather. In the summer I shut off the humidistat control and just use the on-demand buttons located in each bathroom for removing moisture when taking a shower.

Read up on how an air exchanger works.

[LightningBG]

Spear, I think he's asking how would a separate dehumidifier work on a second level.

IMO, it wouldn't work real well. The electricity usage would likely be higher than just having the furnace/ac fan running full time to equalize the temp/humidity.

[spearchucker]

I assumed he was still talking about the humidistat yet, but maybe I am wrong. I would agree that a dehumidifier would not work very well. It would be just as cheap to run the A/C if it is a newer system.

It must not be too big of a deal since bucket hasn't responded in a while.

[bucketmouth64]

yes, I was asking about a mobile dehumidifier. Sorry for the confusion.