register condensation

kentharder

I recently finished my boiler installation and has been up and running for about 2 weeks now, I have a furnace and ac in attic ,I noticed a drip of condensation coming from supply register in master bedroom,my belief is that warm air in room is condensing with cool metal boot in attic, just wondering if i should close all supply registers in house ,but i still have return grills that i can't close, or do i run the fan only on blower in attic a couple times a week to keep things dried out?

Solid_Fuel_Man

Why do you have a furnace in the attic? As well as a boiler. I'm personally not a fan (pun intended) of mechanical equipment in any unconditioned space.

You can get some magnetic sign material like that used on cars in parades and cut it to fit all your registers. Better seal than simply closing the dampers.

kentharder

I have two systems because when we move into the house 16 years ago it was in the attic and since then I remodeled every room and installed boiler system for superior heating system . I'm on a slab. Thanks for the advice on using magnetic material! !

ChrisJ

Solid_Fuel_Man said:

Why do you have a furnace in the attic? As well as a boiler. I'm personally not a fan (pun intended) of mechanical equipment in any unconditioned space.



You can get some magnetic sign material like that used on cars in parades and cut it to fit all your registers. Better seal than simply closing the dampers.

Wow,
You're going to hate me then because not only am I installing A\C in my unconditioned attic, my steamer is basically in an unconditioned space as well as my basement drops into the low 50s and the crawl spaces (steam main and takeoffs) drops into the mid 30s.

Everything in life is a compromise. Especially when working in a 150+ year old house. The only way to get everything into a conditioned space is to knock the building down and start from scratch.


@kentharder I have plans to buy those magnetic covers for my diffusers. I'm hoping, the insulation around everything would stop any condensation,but I also see no reason to leave all of that exposed in the winter.

Gordy

I think @Solid_Fuel_Man is just saying it is not optimal. He is also correct. The best you can do is stop warm air from migrating into the cold ductwork by making diffuser covers. Still may find some condensation on the cover by using a metallic type of cover. Just the simple matter of conduction.

Depending on ductwork round, square, rectangle, elliptical. Snug fitting Foam balls offer a hidden option behind the grill with some rvalue.

I know of 4 homes with Ac in attic, and water based heating. They all had water stains around the ceiling diffusers because they were not covered.

ChrisJ

Is a humidifier in use?
Is all of the ductwork insulated?

cableman

Some a/c vents are aluminum and the magnetic stuff doesnt work.
I air sealed the heck out of my air handler and registers from the attic. I close all vents and cover lowest ones which are on the 1st floor as they were the ones that you could still feel cold air weeping out. I also seal up the return with a simple piece of dow board taped on the inside.
Just have to remember all the vents you block up before you go to turn it back on! My breakers are off in the panel incase someone hits the fan switch.

Solid_Fuel_Man

@ChrisJ what Gordy said is what I meant exactly. Call me a dreamer.... even in new buildings/houses architects shoehorn mechanical equipment anywhere they can fit it. Often that is indeed an unconditioned attic. My thermodynamic engineering mind gets wound up. I just see btu's lost for a lifetime.

kentharder

Duct work is insulated in attic no humidifier

ChrisJ

kentharder said:

Duct work is insulated in attic no humidifier

Are the register boxes well insulated?

I'm assuming your attic is likely insulated pretty good as well, and vented?

@Gordy this is something I didn't realize until this morning.
At work, the attic isn't vented. Same in my house. I'm betting both attics run quite a bit warmer than one that is properly insulated and vented.

Gordy

IT doesn't take much of a delta to
Get down to dew point. Especially in the winter.

ChrisJ

Gordy said:

IT doesn't take much of a delta to
Get down to dew point. Especially in the winter.

70°F @ 25% = 33°F dew point.

kentharder

Attic boxes and attic are well insulated

ChrisJ

kentharder said:

Attic boxes and attic are well insulated

Seems like you have two options.

1: Seal up the attic and pull a lot of the insulation out of the attic floor to warm the attic up.

2: Find a convenient but effective way to seal the vents in the winter. Make sure you disable the furnace.

Option 1 seems pretty stupid, but it is an option.

I've wanted to insulate my rafters for years now, and essentially turn the attic into a conditioned space. Still hasn't happened.

Gordy

https://www.google.com/search?q=attic+temperature+of+vented+attic+in+winter&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari

ChrisJ

Gordy said:

https://www.google.com/search?q=attic+temperature+of+vented+attic+in+winter&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari

You're using Safari?
That just explained a whole lot............

Solid_Fuel_Man

Use mini-splits for A/C and pull it all out of the attic is the right way to do it, albeit the most expense and work.

ChrisJ

Solid_Fuel_Man said:

Use mini-splits for A/C and pull it all out of the attic is the right way to do it, albeit the most expense and work.

I went down this path making decisions for months, starting back in August of 2016.

Minisplits have issues.

Some people don't want equipment hanging in the living space, that has to be washed in the livingspace, and multiple linesets running up the sides of the building all over. I could put my boiler in the livingroom and save the heat it gives off, but I'm not going to.



Mini-splits are also the least repairable and most expensive.

I say this because my opinion of "the right way to do it" and yours appears to be very different.

To me, surface mounting equipment all over a house inside and out is far from the right way to do it. I'll sacrifice some efficiency to hide 90% of the hardware.

As soon as I found out how you wash the evaporators in mini-splits I was done with them.

Gordy

They sure do sell a lot of them for so many issues..........

ChrisJ

Gordy said:

They sure do sell a lot of them for so many issues..........

I listed the issues.
That doesn't mean "they break".

It means there's drawbacks to them.
Compromises, if you will.


This doesn't mean I'm saying @Solid_Fuel_Man is wrong. I'm saying he's not necessarily right.

@Gordy is always wrong, so that's a given.

Solid_Fuel_Man

Wow, I'm not getting involved in this....

However, I have and do install mini-splits, I do NOT, however, have one in my own home. That said I do live within running distance of Canada... so not a lot of cooling, I have a heat pump water heater for that (summer use only).

I certainly agree with @ChrisJ that they have some real drawbacks, trust me I have well over 150 installed. And those installs are getting some age on them now. I would consider ducting one up from a basement (considered a conditioned space in my book). If A/C is of priority. I think attics are for keeping stuff like fake Christmas trees and old lamps and such.

Way too hot in the summer and way too cold in the winter, bad on all accounts for mechanical equipment. And generally bad to very poor access to boot. A basement is far better.

With inverter driven DC compressors the energy saved over conventional equipment is worth it, as long as one has reasonable expectations of performance.

Ok, so I'm a wethead...and heating is my real passion, refrigeration is just something to do in the off season.

ChrisJ

Solid_Fuel_Man said:

Wow, I'm not getting involved in this....



However, I have and do install mini-splits, I do NOT, however, have one in my own home. That said I do live within running distance of Canada... so not a lot of cooling, I have a heat pump water heater for that (summer use only).



I certainly agree with @ChrisJ that they have some real drawbacks, trust me I have well over 150 installed. And those installs are getting some age on them now. I would consider ducting one up from a basement (considered a conditioned space in my book). If A/C is of priority. I think attics are for keeping stuff like fake Christmas trees and old lamps and such.



Way too hot in the summer and way too cold in the winter, bad on all accounts for mechanical equipment. And generally bad to very poor access to boot. A basement is far better.



With inverter driven DC compressors the energy saved over conventional equipment is worth it, as long as one has reasonable expectations of performance.



Ok, so I'm a wethead...and heating is my real passion, refrigeration is just something to do in the off season.

Overall,
I think we both agree @Solid_Fuel_Man
I am just willing to make more sacrifices than you for cosmetics. That, and I just need more usable living space.

Never thought I'd say that.
I generally choose function over form.


@njtommy has been trying to change my mind for months. He loves mini's.

Canucker

> @Gordy said:
> They sure do sell a lot of them for so many issues..........

And a lot of people think a Chevy Cavalier is a good car until they drive a high end Mercedes. @Gordy Just trying to keep the analogy going. Most people don't know what the good systems are, me included. All I really know is that the only time I want air blowing on me in my house is when it's cold air and hot outside. And both systems better be quiet at all times

ChrisJ

Canucker said:

> @Gordy said:

> They sure do sell a lot of them for so many issues..........



And a lot of people think a Chevy Cavalier is a good car until they drive a high end Mercedes. @Gordy Just trying to keep the analogy going. Most people don't know what the good systems are, me included. All I really know is that the only time I want air blowing on me in my house is when it's cold air and hot outside. And both systems better be quiet at all times

There are many things that are less than great that sell really well.
But I wasn't trying to call quality mini-splits an inferior product. Though, I've been told the cheap ones are pretty bad. I don't know first hand though.


As far as air blowing on me, I try to avoid it.
I worked very hard to try and ensure the central air system will never blow on anyone.I used ceiling diffusers and tried to keep my velocity in the right spots to give good mixing.

The last thing I wanted was a cold draft when the system is on.

We'll see, I never did anything like this before, but I did my best to follow the rules and had a lot of help from a few pros.

Canucker

I hear you. I've probably never been around a good forced air system to know any better myself. My last house had an oil fired furnace, with the biggest duct work I've ever seen in a house. I didn't hear the air blowing through that system, just burner and fan motor itself. All that ductwork was probably installed when the house was built in 1947. That said, it can't touch how quiet my radiator heated house is now

ChrisJ

Canucker said:

I hear you. I've probably never been around a good forced air system to know any better myself. My last house had an oil fired furnace, with the biggest duct work I've ever seen in a house. I didn't hear the air blowing through that system, just burner and fan motor itself. All that ductwork was probably installed when the house was built in 1947. That said, it can't touch how quiet my radiator heated house is now

I am by no means an expert with this, in fact I only learned about it a few months ago.

I always thought these vents blew downward at an angle. That's completely wrong. They blow out along the ceiling horizontally.


Notice the dirt pattern on the ceiling. This is from the Coanda effect.



When done properly, the air will be mixed with plenty of room temperature air before dropping off of the ceiling so no one will notice it.