Any HVAC techs in the house?

[kenmac]

LD you can disagree all you want, but you aren't correct..I was in the bus, for 35 yrs I have never taken return air form a basement or a crawl space or attic space..I don't think you'll find it in the code either.. I could go more into detail of why this shouldn't be done, but at this point I'm out.. Ya'll carry on and take return from where ever you wish

 

[ultrarunner]

The place in Washington has a daylight basement and at the suggestion of the new Heat Pump installer I have the fan default on very low when no call for heat or cooling and this has made the entire main floor and basement very nice and uniform temp/humidity wise... the upstairs has a electric heat only furnace and is separate.

 

[General Lee]

you should not be taking return air from any space, other than living space. I would never pull return air from a non living space just to get more return air... this isn't helping you 1 bit ! Your basement return is killing your efficiency .... This company should have fixed your return air problem B-4 installing a unit...
Didn't you say in another thread that you trusted this company ?

Yes, I did say I trust the company to do right. But through the years I've heard mixed reviews on the issue and the return was already installed prior to them coming into the picture.

 

[dadster4]

I was in HVAC for 30+ years in the Chicago area and did load calculations for project homes and large 3-6 system custom homes and need a little more info...ranch? two story? split level? how much glass facing south? any unusually large windows or high ceilings? is most of the basement finished? (an unfinished basement actually LOWERS the unit sizing) If an average 2000 sq. ft. home, 3-1/2 ton is too large and the 4 ton coil makes that worse, in the "old days" a 1/2 ton larger coil was common...not anymore, equipment should be matched. You mentioned that a register was on the same wall as the thermostat...I hope this is an interior wall and not exterior, but the stat should not be anywhere near a supply, it should be close to the return if possible. Another possibility is (since your return vents are noisy) the unit is oversized and the system's ductwork (especially the return sizing) is inadequate for proper airflow and the unit is shutting down prematurely on a low-pressure control and restarting 5 min. later after the control resets...creating your on-off cycle. Minimum size of return duct would be about 200 sq. in. or 24 x 8. Hope this helps :confused3:

 

[LD1]

LD you can disagree all you want, but you aren't correct..I was in the bus, for 35 yrs I have never taken return air form a basement or a crawl space or attic space..I don't think you'll find it in the code either.. I could go more into detail of why this shouldn't be done, but at this point I'm out.. Ya'll carry on and take return from where ever you wish

I am certainly all ears to more detail. Its a good discussion going here, why are you gonna take your 35 years of experience and leave? If we all agreed on everything, there would be nothing at all to discuss.

The fact that my sub-grade basement with poured concrete walls stays a good 15 cooler than my main floor, there are times when it gets hot upstairs, and I dont need ANY cooling from the compressor at all. Simply run the fan and let things "blend". This time of year is a perfect example. Gonna be sunny and ~78 today. Right now its 58. MY whole hose is nice and cool as we had windows open over the night. By 3 or 4 this afternoon, the main level will be getting warm enough I want to cool it down. Instead turning on my geo/compressor/loop pumps, I'll simple turn the fan on and bring some cool basement air up and return some of the warm upstairs air down to the basement.

So I ask, with your experience, why is it a bad thing to only run the fan to get the desired results? vs running the whole system?

I installed the Geothermal myself, but I hired the ductwork out. HE is a friend in the HVAC business and like you, has been in business for ~30-35 years. He knows all kinds of tricks. He said a large return in the basement that can be closed of or mostly closed off for winter heating, and opened up in the summer, is exactly what I needed to make the system operate at its most efficient. And said that his air to air system in his house, is setup the exact same way, only not as nice. AS all he did was cut in a 12x20 opening in his basement return duct, but a return vent over it, and use a stick on magnet/door sign to block it in the winter.

So......so far.....I have one guy (who installed my system) with 30+/- years HVAC experience that says my return air from the basement in the summer time is an excellent thing........and have one guy with 35 years of experience on the internet that says its a bad thing.

I am gonna stick with what I got. Colder air in = colder air out. And the cold air in my house is the basement

 

[Midniteoyl]

Back when I lived in a house with a basement, having a return cut in, and 2 supply vents put in- each able to be opened/closed - was the best thing I ever did. For both comfort and moisture control. In my current home on a crawl, I insulated the floor and walls, removed the insulation from the joists and dump some warm air in in the winter, with no return, and its much more comfortable in the winter.

 

[Sigarms]

So I ask, with your experience, why is it a bad thing to only run the fan to get the desired results? vs running the whole system?

I can't speak for Kenmac, but only say that good practice generailly turn into good habits, which turns into good results.

Generally you don't want to pull return air directly into the return ductwork system from an unconditioned space unless you are treating that return air with some kind of device.

A contractor installs an HVAC system and leaves. He can NOT control what the homeowner does. Sometimes it's hard enough to get the homeowner to change their air filter once a year, let alone monthly, depending on what they have.

 

[LD1]

I can't speak for Kenmac, but only say that good practice generailly turn into good habits, which turns into good results.

Generally you don't want to pull return air directly into the return ductwork system from an unconditioned space unless you are treating that return air with some kind of device.

A contractor installs an HVAC system and leaves. He can NOT control what the homeowner does. Sometimes it's hard enough to get the homeowner to change their air filter once a year, let alone monthly, depending on what they have.

I never said it was an unconditioned space. I said it was an unfinished space.

And by unfinished I mean that If I look up, I see floor joists and plumbing. If I look at the walls, I see poured concrete. And if I look down, I see the 3/8" thick 2x2 foam mats. But it is absolutly a conditioned space, laundry is down there, projector TV, Few couches, pool table, kids toys, etc.

The OP said his basement was unfinished as well. I didnt take that as being unconditioned. I took that to mean the same thing as my area. My basement is also not closed off to the upstairs. The stairwell going to the basement is open. So even if I didnt have any return ducts at all upstairs, and only supplies. That air would still find its way to the basement.

 

[General Lee]

I was in HVAC for 30+ years in the Chicago area and did load calculations for project homes and large 3-6 system custom homes and need a little more info...ranch? two story? split level? how much glass facing south? any unusually large windows or high ceilings? is most of the basement finished? (an unfinished basement actually LOWERS the unit sizing) If an average 2000 sq. ft. home, 3-1/2 ton is too large and the 4 ton coil makes that worse, in the "old days" a 1/2 ton larger coil was common...not anymore, equipment should be matched. You mentioned that a register was on the same wall as the thermostat...I hope this is an interior wall and not exterior, but the stat should not be anywhere near a supply, it should be close to the return if possible. Another possibility is (since your return vents are noisy) the unit is oversized and the system's ductwork (especially the return sizing) is inadequate for proper airflow and the unit is shutting down prematurely on a low-pressure control and restarting 5 min. later after the control resets...creating your on-off cycle. Minimum size of return duct would be about 200 sq. in. or 24 x 8. Hope this helps :confused3:

The house is a rancher w/ an unfinished basement. (walkout) Nearly 2,000 sq feet NOT including the basement. House is approx. 70 feet long with the front facing south, 7 windows facing south, 2 are bay windows and 2 are shaded by the covered porch. There is a cathedral ceiling in the living room. No register on the same wall as T-stat, the register is on a perpendicular wall. T-stat is on same wall as return duct. The main return duct is under sized, one reason they added a second return in the basement. The Main return opening is 20x20 and the downstairs return vent is 14x20. They tell me the coil being 1/2 ton larger then outside unit helps with efficiency??

 

[Sigarms]

I never said it was an unconditioned space. I said it was an unfinished space.

Kenmac stated "for 35 yrs I have never taken return air form a basement or a crawl space or attic space..". From my experience, every state varies per what people use and layout via HVAC systems, but on the east coast, from New York to at least North Carolina, in general, when you here the term crawl space or attic space, it's generally an unconditioned space.

Perhaps he misinterpreted what you stated, I'm not certain, but that is where my comment came from.

I believe what Kenmac is saying in 35 years he has never pulled return air from an unconditioned space (I also believe that is what he meant by "code").