# New to Air Exchangers and low humidity



## beenthere (Oct 11, 2008)

When you bring in 50°F(10C) 50% RH outdoor air and heat it to 70°F(21C), you lower its RH to 24%. 

A member here by the name of Yuri, is from Canada, and he can tell you what you need to do.


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## yuri (Nov 29, 2008)

Where do you live, what city or town and Province?

Looks to me like you have it running continuosly on low speed as the lower switch turns the exchange process on. Turn it to left may shut it off. The dial triggers the exchanger fan to a higher speed to exchange more air and bring in more dry air to drop the humidity if it gets above the setting/setpoint. Sounds to me like running it all the time is drying your house out. You may need a humidifier to bump up the humidity in the Winter and to shut it off when the AC is running in the summer or it will bring in hot humid air and defeat the AC. I have a newer model than yours and don't know the operation of yours for sure. I have a humidifier to bring up the moisture level in my house.


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## Metallo (Dec 23, 2010)

Hi all,

thanks for your comments.

I am in Fredericton (NB) and yes, my air exchanger is running at low speed at the moment, while the button below is like a switch, therefore if I turn it left it turns the exchanger off.
The dial is set to end of scale (should correspond to 80%). I have been suggested for at least 2 weeks and then adjust to 50%.
After 5 days, since nothing changed, my conclusion is probably because my baseboard heaters dry a lot the incoming humidity, so basically in order to see it increasing I will have to wait when the heater is off, correct?
This means I will have to buy a humidifier for the winter season and probably a dehumidifier for the summer in the basement because they say humidity will increase a lot due to the concrete.

Some additional questions:

I wonder, if in winter time you open the windows 15 min. every day, don't you get the same result as having the exchanger on the whole day? 

I have no A/C, does the air exchanger provide any help by letting in warm air and cool it during the summer season?

Have you got any suggestion on which humidifier and dehumidifier brands I should look at?

I read good reviews respectively over the "Air-O-Swiss Ultrasonic 7144 " and the "Dandy DDR7009REE", is this realistic? 

Any other suggestion or advice is very welcomed.

Thank you!
Alex


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## yuri (Nov 29, 2008)

I am not sure what advice to give you as I am used to them in houses with forced air furnaces but I will tell you what I know of electric baseboard heat. The system operation you will have to figure out what works best for you by trial and error.

The problem you can have and may have with baseboard heaters and NO air circulation from the exchanger is cold spots in the corners of rooms and MOLD growing there which is a huge health hazard. That is why they installed the exchanger. The flip side is it can dry out your air if used too much. I would suggest keeping sofas and drapes away from the corners and trying to allow as much natural circulation as possible. Most basements need a dehumidifier for summer and running the exchanger is not necessary then.

I don't know what is a good brand of portable humidifier. I use a Simplicity dehumidifier from HDepot or Rona or Canadian Tire. Costs about $250 but also has a electric heater in it which is good for emergencies. Buy one with a digital display so you can accurately set it at 40% RH. The cheaper ones only have low/med/high which means what in RH?

Opening the window is not good, you need air movement/circulation in the cold corners/areas to prevent condensation and mold, that is what the exchanger is designed for.


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## Metallo (Dec 23, 2010)

Yuri,

thank you for your advice, much appreciated indeed :thumbsup:

Regards,
Alex


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## Metallo (Dec 23, 2010)

Yuri,

...forgot to ask, I have a fireplace operating on city propane, between the fireplace and the baseboard heater, which one dries more?
I guess the fireplace is cheaper to operate?

Alex


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## yuri (Nov 29, 2008)

I don't know. Don't know what your elec costs vs Propane are. I would imagine elec is cheaper to use as fireplaces are NOT very combustion efficient and elec is 100% efficient. Elec is usually much cheaper than Propane due to the transportation cost to deliver Propane and the tank rental etc. Propane is next to fuel oil for being VERY expensive to use where I am.


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## beenthere (Oct 11, 2008)

Where does the fireplace gets its air for combustion. If from inside the house, that is also causing a lot of your dry air problems. Since it forces more fresh outside air to be drawn into the house.

Opening the windows for 15 minutes isn't the same as the HRV running intermittently through out the day. Since the open windows only freshens the air for that short period of time. 

The HRV should generally only run for X time per hour. X depending on the size of the house. And the number of people in it.

Try running it on low for only 10 minutes every hour(do this on a weekend when you have time to manually turn it on and off. You should see an improvement in your indoor humidity..


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## HVACDave (Oct 16, 2007)

By chance do you use the HRV for bathroom exhaust as well? Some systems are tied into the bathroom as the exhaust fan on a switch which will just keep the HRV running the whole time the switch is on, others use a timer to make it an intermittent operation, others have dedicated exhaust fans for the bathrooms, any idea if yours has this option?


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