reclaiming heat from dryer...need ideas. - Page 2

MN Renovator · 11-08-13, 05:45 PM

"But one of the ironies is that in many places that have deep cold winters, home interiors can suffer from excessively dry air, and mechanical/electric humidifiers are employed.... while in a different part of the house, mechanical/electric devices are employed to remove humidity (and fiber) from clothes."

If you have issues with excessively dry air, there is too much ventilation. Either through infiltration, which will need air sealing. ..or through mechanical ventilation which will need to have the ventilator turned to a lower setting or a timer setup for reduced runtime.

I have clean fresh air in my house and there isn't a point where I'm ever thinking of needing more humidity, its usually a balance of trying to remove the humidity through adding more ventilation and trying to be careful when taking a shower to be sure the fan stays on long enough after the shower to remove the moisture and being careful when boiling pasta water, etc. Moral of the story, seal up the house and don't overventilate.

AC_Hacker · 11-08-13, 07:44 PM

[QUOTE=MN Renovator;32957...I have clean fresh air in my house...[/QUOTE]

What is your location (zip code)?

-AC

NiHaoMike · 11-08-13, 09:27 PM

Quote:

Originally Posted by AC_Hacker

The heat-pump clothes dryers seem to wok great, but they still beat the clothes to deth, and cost $1000+.

The ready made ones, yes, but it's possible to hack together something for much less than that. The cabinet with a modified window unit mounted on the side (along with some fans to circulate and ventilate the air inside) would not put much (if any) wear and tear on the clothes, and would be a great idea if a clothesline isn't an option for you. Or the previously mentioned dehumidifier blowing into a closet, for that matter.

MN Renovator · 11-08-13, 11:31 PM

Quote:

Originally Posted by AC_Hacker

What is your location (zip code)?

-AC

55369 Let me know what you find. We get plenty cold (and unfortunately humid and hot, high dew point in the summer) here.

AC_Hacker · 11-09-13, 01:52 AM

Quote:

Originally Posted by MN Renovator

55369 Let me know what you find. We get plenty cold (and unfortunately humid and hot, high dew point in the summer) here.

Not knowing any better, I chose crystal Airport, MN as the place to collect relevant data.

Your average HDD is 8471, which for temperate US would qualify as deep winter.

In thinking about your scheme, I can see that a house that is well sealed and well insulated could enjoy a balance between normal humidity generated by living conditions, by tweaking the amount of fresh air in.

And with a house that is not well sealed and not well insulated, the energy that is going into very frequently raising the temperature of cold air... with it's large-scale drying effect, would not be offset by moisture generated by normal living.

It all has me considering some kind of heat recovery scheme, too. This could help further reduce the rate of heating cycles required to maintain temperature... and would probably have some, probably minor, effect on humidity balance.

So yes, a house with uncomfortably low humidity conditions is quite likely also a house with poor infiltration sealing and/or poor insulation.

-AC

MN Renovator · 11-09-13, 03:16 AM

Crystal airport is a great point to use data from. I'm at a point where I've got the basement sill plates sealed. In the attic top plates except the most outside facing ones, plumbing penetrations, and electrical penetrations are sealed. Outside facing outlets and switch plates are gasketed. Window gaps are spray foamed. I'm missing the door gap sealing and this point I'm not sure what's left for air sealing other than ditching the atmospherically vented/natural draft water heater and furnace(76% efficient). I think if it weren't for those I'd be quite a bit lower on the natural gas usage but those also pull a decent amount of outdoor air in too. 30 cfm Panasonic whisper green bathroom fan suck is my current setting and the air feels, smells, etc great to me. IMHO ASHRAE has figures that are looking for ACHnatural figures rather than actual forced ventilation plus a little added mechanical. I don't understand how people think their house is sealed perfectly, when its not but then you add mechanical ventilation figuring its the only air exchange between the outside when it isn't.

11-08-13, 07:44 PM	#12
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	[QUOTE=MN Renovator;32957...I have clean fresh air in my house...[/QUOTE] What is your location (zip code)? -AC __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker...

11-08-13, 05:45 PM	#11
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 939 Thanks: 41 Thanked 116 Times in 90 Posts	"But one of the ironies is that in many places that have deep cold winters, home interiors can suffer from excessively dry air, and mechanical/electric humidifiers are employed.... while in a different part of the house, mechanical/electric devices are employed to remove humidity (and fiber) from clothes." If you have issues with excessively dry air, there is too much ventilation. Either through infiltration, which will need air sealing. ..or through mechanical ventilation which will need to have the ventilator turned to a lower setting or a timer setup for reduced runtime. I have clean fresh air in my house and there isn't a point where I'm ever thinking of needing more humidity, its usually a balance of trying to remove the humidity through adding more ventilation and trying to be careful when taking a shower to be sure the fan stays on long enough after the shower to remove the moisture and being careful when boiling pasta water, etc. Moral of the story, seal up the house and don't overventilate.

11-09-13, 03:16 AM	#16
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 939 Thanks: 41 Thanked 116 Times in 90 Posts	Crystal airport is a great point to use data from. I'm at a point where I've got the basement sill plates sealed. In the attic top plates except the most outside facing ones, plumbing penetrations, and electrical penetrations are sealed. Outside facing outlets and switch plates are gasketed. Window gaps are spray foamed. I'm missing the door gap sealing and this point I'm not sure what's left for air sealing other than ditching the atmospherically vented/natural draft water heater and furnace(76% efficient). I think if it weren't for those I'd be quite a bit lower on the natural gas usage but those also pull a decent amount of outdoor air in too. 30 cfm Panasonic whisper green bathroom fan suck is my current setting and the air feels, smells, etc great to me. IMHO ASHRAE has figures that are looking for ACHnatural figures rather than actual forced ventilation plus a little added mechanical. I don't understand how people think their house is sealed perfectly, when its not but then you add mechanical ventilation figuring its the only air exchange between the outside when it isn't.