Progress!

[Sigarms]

HVAC installers I've dealt with seem to hate doing the calculations. I think they'd rather work in a blazing hot attic than actually run the numbers.

There is a difference between a service tech selling and a "HVAC salesman" selling to the homeowner, and smart businesses realize this, and they have service techs selling because they seem more trustworthy to homeowners (really really good service techs will want to repair the equipment vs just replacing it, no matter the age of the equipment because they don't want to replace anything and can fix everything)

FYI the smartest salesmen in HVAC I know used to be GREAT service techs, but when you get older, even the service side can suck over years as your body can't do what it once did.

Part of the issue with HVAC companies is its believed there is better money is on the service side vs the install side. However, GOOD HVAC companies realize a great installer is worth just as much as a great service technican (installers work standard shifts and don't have to be on call which is a great advantage vs the install side).

On an existing home, given the age, the insulation as well as taking actual readings in the home vs what the homeowner tells you, a block load would only take you 5-10 minutes to verify what you already think and know on an existing home. But also keep this in mind, service techs make more money on more service calls, so to take time to sell takes time out of their work. Interesting dichotomy because unlike car lots, HVAC companies have to come to your home directly.

Thing is, we are talking about a newly built home, not a home 20 to 50 years old. Insulation along with window coverage as well as a host of other variables can put the load difference between 1-3 tons easily on the same size home. This is why many states are requiring a load to be done on all new homes.

I don't disagree with the rest of what you said for older homes, but on newer home builds, if the load is sized correctly and the correct split ducted system installed, a mini split would not be needed IMO. Homes are getting more tighter than you can imagine. One reason why fresh air ventilation is being required for new residential installs as well.

I'm a huge proponent of ductless mini splits mysel, and even people who I consider experts in other areas call me for my peon advice on ductless. To the dismay of mini split manufacturers, I'm not a huge propronent a home using nothing but ductless if sizing is done correctly for ducted systems (required service over the years being a big obstacle IMO). That is not to say a 2 or 3 zone ductless mini split not requiring auto changer can't help.

 

[2manyrocks]

It's not just about the load, another issue is duct sizing, material, placement, air velocity that all play into whether the system is actually quiet.

One thing I seem to see is an air handler mounted relatively close to the wall, and I start to wonder where the return is located, how it is sized, and what level of noise transmission is going to be experienced.

So in an area where an entertainment system will be located, I strongly prefer a mini split system because the noise level is not as intrusive as a normal ducted system.

 

[Sigarms]

It's not just about the load, another issue is duct sizing, material, placement, air velocity that all play into whether the system is actually quiet.

Please note, I mentioned Manual D as well as Manual J as well as manual S

If ductwork is sized properly along with insulated and sealed, there should be no problems.

Particularly with older homes and construction, harmonics with working HVAC equipment can be like chasing a snipe with "sensitive ears".

 

[Torvy]

AC update: return is only coming in the above the maintenance door:

The dehumidifier is stand alone, not connected to air handler.
Here is a better shot of the unit:

 

[Torvy]

The shower tile has been laid. It is not 100% done. They originally installed the wrong tile, so that set us back a bit.

 

[2manyrocks]

Trying to understand what's actually happening.

So they installed a return grill over the maintenance door in case the door gets shut and then the return air is being sucked into bottom of the air handler sitting on the wood platform?

When the door is shut and the air handler is running, are you noticing much noise?

What is the purpose of the metal foil duct to the right of the air handler?

Somehow the dehumidifier is supposed to suck the moisture out of the air flowing past it into the air handler return?

Is the dehumidifier actually doing anything to remove moisture beyond what the a/c system is removing?

 

[2manyrocks]

I thought it was up and running so they could work on the interior in the cool instead of the heat and humidity?

I haven't dealt with installing a dehumidifier in connection with an air handler. I'm scratching my head wondering why the air handler isn't just going to pull nearly all the air right into the air handler and hardly any is going to flow through the dehumidifier while the air handler is running?

Another thing that concerns me is having the air handler right next to the drywall because that could amplify any noise or vibration if the drywall acts like a sound board.

 

[Sigarms]

I haven't dealt with installing a dehumidifier in connection with an air handler.

Dehumidifer in my basement.

The prefered method is return to return, but the ductwork was installed in 1988 and I tried to keep it simple. Keeps the house at 40% which is low, but the way I like it in the 3 hot and humid summer months.

I put in a new system in 2007, and this system was put in last year because it was worth it to me vs the repair. 15 years was a good run IMO on the first system I put in, but was able to run extensive tests with the dehumidifier with a single stage X-13 system, and finally could run tests with a 2 stage variable speed air handler system installed here.

Per Apriliare instructions (not Santa Fe).

 

[2manyrocks]

So the recommended method is to hold the air captive in duct so it can't skate past the dehumidifer like it would in an open return.

 

[Torvy]

Haven't been there enough since it has been running to notice any noise. It seemed quiet enough this morning. I could see water coming out of the pipe outside, so the dehumidifier is doing something. Exterior unit was spinning away. I took a shot of it, but it didn't turn out well. For what it's worth, it is called a "Achiever Plus". Means nothing to me.

Normal operation when we move in will be door closed 99% of the time. My wife wanted the cat box be in there. It sounded like a bad idea to me. I'm working on a 'catio' setup that will keep their mess outside, but allow them access. As is, they are MIA right now, so I have more time to deal with that eventuality.

 

[Sigarms]

So the recommended method is to hold the air captive in duct so it can't skate past the dehumidifer like it would in an open return.

The idea is to take the conditioned air from the air stream, dehumidify it, and dump it back into the conditioned airstream.

The question becomes if a dehumidifier is worth the extra money vs a multi stage variable speed air handler system that should reduce the humidity level vs a single stage variable speed constant torqure blower motor (AKA "X-13").

Personally from my own experience, I'd just go with a base model minimum SEER HVAC X13 blower system and instead of the money for multi stage variable speed, go with a whole house dehumidifer and duct it into your system.

HOWEVER, a dehumidifier will not save you money on your electric bill. For what it's worth, my wife doesn't care

 

[Torvy]

So the recommended method is to hold the air captive in duct so it can't skate past the dehumidifer like it would in an open return.

In theory, I don't think it matters. The dehumidifier processes the air it hits. The unit is moving air in the room, which is drier than outside or the rest of the house.
The only experience I have with dehumidifiers is a stand alone one my wife had in a place we owned a couple of years ago. Had to manually empty it. Made a huge difference as long as it was operational. If it got full, it stopped. It was nowhere near the ac unit. Similarly, as a kid we had a humidifier. Same concept in reverse.

Here in East Texas, the dewpoint from May to Sep is above 65 degrees for anywhere from 15-28 days a month on average. The locals know about dehumidifiers. I didn't even ask about one, it is 'standard' for installation around here.

 

[Sigarms]

Haven't been there enough since it has been running to notice any noise. It seemed quiet enough this morning. I could see water coming out of the pipe outside, so the dehumidifier is doing something. Exterior unit was spinning away. I took a shot of it, but it didn't turn out well. For what it's worth, it is called a "Achiever Plus". Means nothing to me.

What I'm curious about when you move in is turn the dehumidifer off for a week and see what your RH is. Then turn the dehumider on and compare the RH values.

It looks like they are pulling return air from the room into the dehumdifier and then dumping the air from the dehumidifier on a 4" non isulated flex line into the duct system (it wouldn't make any sense any other way).

Not the way I would recommend it, but hey, if it works, it works

 

[Torvy]

One of the downsides to rural life. There are fewer professionals for any given field. It's a gamble. Sometimes you get someone awesome, sometimes you get someone who just bids cheap. Most of us would never know. This is moreso the case in our situation since we are not from the area. No way to know if they are competent.

I may try your idea. It is miserably humid this time of year. Probably don't need to go a full week. Haha

 

[Sigarms]

One of the downsides to rural life. There are fewer professionals for any given field. It's a gamble. Sometimes you get someone awesome, sometimes you get someone who just bids cheap. Most of us would never know. This is moreso the case in our situation since we are not from the area. No way to know if they are competent.

I may try your idea. It is miserably humid this time of year. Probably don't need to go a full week. Haha

On a new home build with you paying good money, I would respectfully tell you I would not take that attitude.

Definately get a static pressure test done on start up.

I could be over reacting as I have no clue how things are done in Texas, but from what I've seen on that system, I would definately be asking questions. That's YOUR right as a buyer.

Off tangent, but this is the nature of HVAC. No one sees it like they do bathrooms or kitchens. I've been in some pretty expensive houses and the end user has the cheapest thermostat you can find on the wall. Hey, I get if it works it works with a t-stat, but the cheapest one you can find for a very expensive house makes no sense to me.

 

[Torvy]

My problem is that I don't know what I don't know. As a typical consumer, as long as the AC works and the power bill is not too high, we figure it works. A few years down the line, it is still working, we are happy. That being said, we are blissfully unaware that a properly installed and/or better system would have 1/2 the power draw and last 2x as long. So the inferior contractors still get jobs.

I am all about getting those tests done. The problem is that I would need to study what they meant to have any clue. What can reasonably be done to fix an issue? The house is already well behind schedule. As of tomorrow night, I am officially homeless.

 

[2manyrocks]

I've been in houses where the returns were really noisy, and thought they needed to be changed, but it would get expensive to move the air handler because of all the refrigerant lines, wiring, and ductwork involved.

Generally, you want to see an air handler and return done in a way that baffles the air flow and any operation noise from the air handler so it's not bothersome in your living space. If you are standing right in front of it in your equipment room, you're going to hear it directly. What you don't want is to be in your living space and hear it like you were standing in front of it because it isn't effectively isolated.

I'd want to see it and hear it up and running before paying or at least having a holdback to protect you.

Once a sub gets paid, leverage over them to get them to correct or change something gets to be harder.

Do you have power to run the system now to check to see if it operates like you want? I'm assuming there is electrical service outside...is there some way to get power to check the system operation?

 

[Torvy]

I've been in houses where the returns were really noisy, and thought they needed to be changed, but it would get expensive to move the air handler because of all the refrigerant lines, wiring, and ductwork involved.

Generally, you want to see an air handler and return done in a way that baffles the air flow and any operation noise from the air handler so it's not bothersome in your living space. If you are standing right in front of it in your equipment room, you're going to hear it directly. What you don't want is to be in your living space and hear it like you were standing in front of it because it isn't effectively isolated.

I'd want to see it and hear it up and running before paying or at least having a holdback to protect you.

Once a sub gets paid, leverage over them to get them to correct or change something gets to be harder.

Do you have power to run the system now to check to see if it operates like you want? I'm assuming there is electrical service outside...is there some way to get power to check the system operation?

It is running now. The bright side, assuming it is noisy, is that it is on the opposite corner from the MBR.

 

[2manyrocks]

Having the return tucked away in some corner of the house will be less bothersome than the returns that some builders place right in the living room area where you can't get away from the HVAC noise even if you wanted to. A free flowing system without obstructions will also be quieter than a system that has a bunch of restrictions in it.

If you and your wife are happy with the install, then one less thing to worry about.

 

[ultrarunner]

On my few residential installs I took the advice of a retired A/C contractor who told me to oversize the return ducting and register and put a 180 in the return path…

For whatever reason they have all been very quiet.

Two stage blowers have also worked well as the maintain temp speed is much lower and enough to keep air circulating.