Couple of questions if anyone has experience.

Building a house on galveston bay so will have humid salt air, was planning on using fiberglass insulation but HVAC guy said his engineer balked at that and wants the house to be spray foam insulation. I was under the impression that was a bad idea on waterfront especially salt water?

I assume the insulation price will go up but maybe HVAC is offset with lower tonnage needed along with a variable speed unit? We havent gotten that far yet.

Also anyone have thoughts on Pex A vs Pex B piping?

Maybe he is thinking closed cell foam. That's pricey. Have you discussed installing a whole-home dehumidifier with your variable unit?

Yes if I do fiberglass insulation I will put in a dehumidifier

Here's the deal. Don't waste a bunch of money on a high seer variable speed unit on Galveston Bay, unless you're filthy rich. Your environment there is only going to give you a five year (guess) life of your outdoor unit due to the corrosive nature of the air. I would recommend going foam, 15 seer single stage, whole home dehumidifier with a completely separate duct system into each room. Think one very small register per room from the dehumidifier near the windows and one larger hvac register near the inner wall blowing out toward window. Then install properly sized returns to every bedroom from the main hvac.

Why you ask?

Because the high seer unit doubles in cost from the lower seer and you won't own it long enough to pay itself off before it's fallen apart. A single speed unit will give you plenty of sensible capacity to cool and heat the house 80% of the time and the dehumidifier will give you the extra latent capacity that you need the other 20% of the time. Two separate duct systems because we are learning that dehumidifiers fall on their face when you put their fan capacity up against the static pressure of the main hvac systems blower. The other and larger issue is that when ducted together it is generally required that the fan of the hvac system run at the same time as the dehumidifier, but there's a problem. The ac has just shut off and your evaporator coil and pan have a few quarts of water in them that has yet to drain and now you're blowing air across it putting that moisture right back in the airstream being blended with the dry air of the dehumidifier. These are lessons I've learned the hard way by doing what everyone else was doing and getting the same results. I've challenged the manufacturers and their thinking and we are slowly making headway.

Air conditioning is a science and an art and nothing is ever the final way to do it.

Definitely not filthy rich and dont want to waste money. I will say this on Im not on galveston island or tiki, but closer to the ship channel area so hopefully my air is not as corrosive as as straight up galveston.

I am leary of the foam house. Seems like its ripe for condensation ? The house is already decked too with radiant barrier decking which I am not sure if that causes a foam house issue. Would also change my hot water heat to a tankless, i would have to close off some soffitt vents and change my room to no vent ridges...so lots of changes at the last minute and no telling what expense. That makes me nervous.

I agree on the variable speed units being a waste. I had read maybe even staying 14 seer was better than going up to 16 seer.

I wouldn't be afraid of fiberglass, just know that your unit will be larger and closer to the old 500sqft/ton than say with foam. Either way a dehumidifier in this part of Tx is a good investment, not a cheap investment. A 14 Seer and a dehumidifier will cost about the same as a 17+ Seer and in my option do as good or better of a job cooling.

You're right about the changes necessary for a full foam house such as fresh air, combustion air, etc. Any change during construction is an opportunity for a builder to make up for missed revenue somewhere else. Long ago a builder got mad at me that a legit change order I submitted was for the actual cost of the change, he educated me that a change order is a penalty for someone not doing their job right the first time.

Good luck. Keep us posted.

AgAcGuy dropping bombs on here! Great stuff! What part of Texas are you located?

AgAcGuy12 said:

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I wouldn't be afraid of fiberglass, just know that your unit will be larger and closer to the old 500sqft/ton than say with foam. Either way a dehumidifier in this part of Tx is a good investment, not a cheap investment. A 14 Seer and a dehumidifier will cost about the same as a 17+ Seer and in my option do as good or better of a job cooling.

You're right about the changes necessary for a full foam house such as fresh air, combustion air, etc. Any change during construction is an opportunity for a builder to make up for missed revenue somewhere else. Long ago a builder got mad at me that a legit change order I submitted was for the actual cost of the change, he educated me that a change order is a penalty for someone not doing their job right the first time.

Good luck. Keep us posted.

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Agreed if I go fiberglass I will put in the dehumidifier as part of the original install.

So you are saying it should have separate ducts ?

I have one guy quoting me one 5 ton with a zoning system or 4 and a 2 without the zoning. I kind of like the idea having two units in case one is down you still have some rooms that are cooled vs having zero.

What is recommended for plumbing these days?

I see everyone is going to the manifolds but not sure I want to do that.

Also what is everyones thoughts on pex A uponor vs pex b ?

I'd definitely go with the smaller units split up. I try like heck to not install new five ton units.

I know your ac guy will think I'm crazy for the separate duct idea but I'm not. It's not expensive duct either, it will be 4" duct and 8x4 ceiling registers and one return in a hallway for the dehumidifier about 16x25 if done the way I'd do it. I try to live by the motto of doing right now so you won't do it right later.

I have no opinion on your plumbing as if it were my house I'd be soldering my own copper in because I can. I couldn't tell you the difference between pex.

I will add that if having gas installed spend the money and get black iron. I just had a customer last week who had a new roof put on and guess where a nail went….right through the yellow flex line where it comes out of the top plate near the eave. Her attic was filling with gas and it could have been bad. Thankfully she has a good ac guy and I was able and willing to search for the leak even though it wasn't on my equipment. I killed the gas at her meter and opened all the doors and windows in the house. This is the second time I've found a nail in a gas line this year.

AgAcGuy12 said:

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I'd definitely go with the smaller units split up. I try like heck to not install new five ton units.

I know your ac guy will think I'm crazy for the separate duct idea but I'm not. It's not expensive duct either, it will be 4" duct and 8x4 ceiling registers and one return in a hallway for the dehumidifier about 16x25 if done the way I'd do it. I try to live by the motto of doing right now so you won't do it right later.

I have no opinion on your plumbing as if it were my house I'd be soldering my own copper in because I can. I couldn't tell you the difference between pex.

I will add that if having gas installed spend the money and get black iron. I just had a customer last week who had a new roof put on and guess where a nail went….right through the yellow flex line where it comes out of the top plate near the eave. Her attic was filling with gas and it could have been bad. Thankfully she has a good ac guy and I was able and willing to search for the leak even though it wasn't on my equipment. I killed the gas at her meter and opened all the doors and windows in the house. This is the second time I've found a nail in a gas line this year.

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Do you want to bid my house? Seriously lol.

I am with you, I want this done right up front and not after the fact.

Still trying to figure out if I want to go full foam home. Had insulation guys out today and they were telling me i would have to add in some walls to do a foam house in my attic so some expense in lumber plus the actual insulation is about 2-3x the cost. Not sure what AC costs will be, if going down in tonnage will make that a wash?

Also one of the things they keep saying in a foam house its going to save my mechanicals in the attic as it wont have salt air running over it and will last longer?

Dehumidifer is a necessity.

I owned an old, small beach house and we used a portable one when down there. On a single weekend, we would have to empty it at least twice. It pulled a ton of moisture out of the air, and made a huge difference in the comfort level. Would have loved to have had a built-in one.

Definitely go Pex A/Uponor. It's a much superior product. Better pipe, better connections, better fittings, less likely to crack if frozen or kinked, etc, and it's easier to install (or make repairs down the road). The only down side is you can't run to your local Lowe's/HD to get repair parts if you need, you have to get them from a plumbing supply store. It's a much a better product though, so you likely won't need to make repairs anyways.

Source: I have 10+ years in construction management and 3.5+ years as an inspector for an MEP engineer. We allow/spec Uponor Pex A on commercial projects, and would never ever allow Pex B on a commercial project. I also have Pex A in my house that I installed myself.

drummer0415 said:

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Definitely go Pex A/Uponor. It's a much superior product. Better pipe, better connections, better fittings, less likely to crack if frozen or kinked, etc, and it's easier to install (or make repairs down the road). The only down side is you can't run to your local Lowe's/HD to get repair parts if you need, you have to get them from a plumbing supply store. It's a much a better product though, so you likely won't need to make repairs anyways.

Source: I have 10+ years in construction management and 3.5+ years as an inspector for an MEP engineer. We allow/spec Uponor Pex A on commercial projects, and would never ever allow Pex B on a commercial project. I also have Pex A in my house that I installed myself.

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Thank you thats exactly what I have heard as well from a friend that works at a national home builder, they only use uponor.

Id really like to stay away from manifolds as well honestly as well.

AgAcGuy12 said:

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I'd definitely go with the smaller units split up. I try like heck to not install new five ton units.

I know your ac guy will think I'm crazy for the separate duct idea but I'm not. It's not expensive duct either, it will be 4" duct and 8x4 ceiling registers and one return in a hallway for the dehumidifier about 16x25 if done the way I'd do it. I try to live by the motto of doing right now so you won't do it right later.

I have no opinion on your plumbing as if it were my house I'd be soldering my own copper in because I can. I couldn't tell you the difference between pex.

I will add that if having gas installed spend the money and get black iron. I just had a customer last week who had a new roof put on and guess where a nail went….right through the yellow flex line where it comes out of the top plate near the eave. Her attic was filling with gas and it could have been bad. Thankfully she has a good ac guy and I was able and willing to search for the leak even though it wasn't on my equipment. I killed the gas at her meter and opened all the doors and windows in the house. This is the second time I've found a nail in a gas line this year.

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So I talked to a friend of mine who used to own a AC company and has lived on the salt water. This was his recommendation:

1. Two stage hvac (gas heat or heat pump)
2. Dehumidifier in attic with ducts on each end of the home terminated in attic space.
3. Outside air with motorized damper to dehumidifier to keep positive pressure in space (must have adjustment for minutes per hour of outside air)
4. If manual J is 5 tons or less then install 1- 5 ton 2 stage system with 3 zones. One in master area, one in living area , and one in remaining bedrooms. Install bypass damper exhausting into attic
5. Install supply and return duct into attic from system (not trying to keep the area as cool as the living area, just tempered)
6. Be certain of all foam insulation integrity and 100% seal from outside to inside of home. The envelope must be sealed properly
7. Any garages and/or porches are considered outside of the home and must be separated by a foam insulated wall from the living space

Curious on your thoughts on that? The manual J that one company recommended was either a 4 and a 2 or one 5 two stage. So definitely in that 5-6ton range.

drummer0415 said:

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Definitely go Pex A/Uponor. It's a much superior product. Better pipe, better connections, better fittings, less likely to crack if frozen or kinked, etc, and it's easier to install (or make repairs down the road). The only down side is you can't run to your local Lowe's/HD to get repair parts if you need, you have to get them from a plumbing supply store. It's a much a better product though, so you likely won't need to make repairs anyways.

Source: I have 10+ years in construction management and 3.5+ years as an inspector for an MEP engineer. We allow/spec Uponor Pex A on commercial projects, and would never ever allow Pex B on a commercial project. I also have Pex A in my house that I installed myself.

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It really is amazing how easy the Uponor stuff is to install. Expand the fitting, mate it up to the connection and hold it for a 5 count...and done.

Jack Pearson said:

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AgAcGuy12 said:

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I'd definitely go with the smaller units split up. I try like heck to not install new five ton units.

I know your ac guy will think I'm crazy for the separate duct idea but I'm not. It's not expensive duct either, it will be 4" duct and 8x4 ceiling registers and one return in a hallway for the dehumidifier about 16x25 if done the way I'd do it. I try to live by the motto of doing right now so you won't do it right later.

I have no opinion on your plumbing as if it were my house I'd be soldering my own copper in because I can. I couldn't tell you the difference between pex.

I will add that if having gas installed spend the money and get black iron. I just had a customer last week who had a new roof put on and guess where a nail went….right through the yellow flex line where it comes out of the top plate near the eave. Her attic was filling with gas and it could have been bad. Thankfully she has a good ac guy and I was able and willing to search for the leak even though it wasn't on my equipment. I killed the gas at her meter and opened all the doors and windows in the house. This is the second time I've found a nail in a gas line this year.

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So I talked to a friend of mine who used to own a AC company and has lived on the salt water. This was his recommendation:

1. Two stage hvac (gas heat or heat pump)

I shy away from two stage anything above 3ton. Why? Distance. On a house that requires anything that big you're going to have duct runs of at least 30' somewhere. When that unit comes on in first stage you're at 70% capacity. Wherever that farthest room is will not be comfortable. I found this out in my own home. I installed a 4t 17seer two stage and guess where the longest duct run is, to my master suite. Guess who was immediately 5-7 degrees warmer. Me. So I had to wire the unit to run as a single stage until I was able to install a ducted Mitsubishi for my master suite alone. My poor kids froze at 67 so I could be 72 for two months.

2. Dehumidifier in attic with ducts on each end of the home terminated in attic space.

So he is essentially just dehumidifying the attic?

3. Outside air with motorized damper to dehumidifier to keep positive pressure in space (must have adjustment for minutes per hour of outside air)

I'm not a huge fan of outside air. Yes it's technically code and is important in commercial settings but I have kids. We get plenty of outside air.

4. If manual J is 5 tons or less then install 1- 5 ton 2 stage system with 3 zones. One in master area, one in living area , and one in remaining bedrooms. Install bypass damper exhausting into attic

I hate zone systems. Zone with equipment, not ducting. If you decide to zone with gas heat you better make sure your smallest zones airflow is equal to your furnaces minimum cfm output. I have not seen one done right yet.


5. Install supply and return duct into attic from system (not trying to keep the area as cool as the living area, just tempered)

So this opens a can of worms because now you've essentially made your attic a plenum and by code everything in the attic needs to be plenum rated. Your foam will need to have the fire barrier, wires in conduit etc. I know it gets done without it being done right but I'd shy away from this.

6. Be certain of all foam insulation integrity and 100% seal from outside to inside of home. The envelope must be sealed properly

This is a no brainer. I've seen a lot of shoddy foam jobs. You have to check all the difficult areas over real well. I've seen foam vary from 1.5" to 5" in the same joist.
I had a pre I'd meeting this morning at A&M and the topic of why spray foam isn't part of the energy code came up and I believe it's because of the variability of the quality of install.

7. Any garages and/or porches are considered outside of the home and must be separated by a foam insulated wall from the living space

That or foam them. The problem I see with the wall (I've seen a mesh net installed that's then foamed) is that a year later Chuck in a truck from suddenlink cuts a hole in it to run the cable across the attic and now your barrier is forever compromised, if I liked foam and was doing my house I'd pay to do the entire envelope.

Curious on your thoughts on that? The manual J that one company recommended was either a 4 and a 2 or one 5 two stage. So definitely in that 5-6ton range.

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Send me a set of plans and specs to nowlivingforme@hotmail.com if you'd like and I'll take a look at it. I wish I had time to actually run down there and do the work for you but it sounds like you're pretty close to needing it done and I'm booked until December thankfully.

Thank you I will send a copy of your way here shortly.

Pex Manifolds are a waste and unnecessary. Way more pipe used than just running splits from the main. Its like an electrical panel for plumbing, however, most people are not turning off water to certain areas on a regular basis like you do electrical. And all your fixtures have stops to turn them off anyway if you are replacing a toilet or faucet. PexA is probably more common but PexB is fine and used a lot also. Either way, you will have to hire someone to do repairs/install unless you want to drop a lot of money on tools. Emergency repairs can be done with sharkbite type pushon fittings if needed by any homeowner.

aquaboss98 said:

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Pex Manifolds are a waste and unnecessary. Way more pipe used than just running splits from the main. Its like an electrical panel for plumbing, however, most people are not turning off water to certain areas on a regular basis like you do electrical. And all your fixtures have stops to turn them off anyway if you are replacing a toilet or faucet. PexA is probably more common but PexB is fine and used a lot also. Either way, you will have to hire someone to do repairs/install unless you want to drop a lot of money on tools. Emergency repairs can be done with sharkbite type pushon fittings if needed by any homeowner.

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I agree the pex manifiolds look cool but seem unnecessary......and because of the limited manifold connections they were saying I would need two hot water heaters which I dont want.

In a 3200 sq ft house, what is the consensus on one hot water heater or two? Only 3 people in the house on a regular basis .


Sounds like Pex A is consensus on tubing over Pex B?

Plumbing options on the house

Original bid- two manifolds, two tankless hot water heaters in the attic using Pex B. (Foam house)

Plan B - No manifolds, one tanked ho****er heater in the garage (cant put in attic due to foam house) using Pex A

Plan C - No mainfolds, one tankless hot water heater in the attic using Pex A


I would assume original bid cost more with the manifolds and additional hot water heater plus if using two manifolds the Pex usage has to be much greater?

Definitely pex A.

Definitely no manifolds. They are kind of unnecessary, increase expense, and are prone to cracking during freezes. (The plastic they are made of doesn't expand and contract like pex A piping does)


Is your water heater gas or electric? If gas, I prefer tank type, because it can run with no electricity, but even gas fired tankless heaters require a 120v connection. That being said, either way, I would still go with a tank type and then have them plumb a recirculation loop back to the tank and recirculation pump in-line on the return side.
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drummer0415 said:

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Definitely pex A.

Definitely no manifolds. They are kind of unnecessary, increase expense, and are prone to cracking during freezes. (The plastic they are made of doesn't expand and contract like pex A piping does)


Is your water heater gas or electric? If gas, I prefer tank type, because it can run with no electricity, but even gas fired tankless heaters require a 120v connection. That being said, either way, I would still go with a tank type and then have them plumb a recirculation loop back to the tank and recirculation pump in-line on the return side.
.

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Thanks yes I will have gas. To me it seems like the best answer is just old school tank.

We have a 40 gallon now, wife has a jacuzzi tub, I take long hot shower, teenage daughter takes long showers and we never run out of hot water, but just to be safe I think increasing to a 50 gallon one tanked should be sufficient.

Zurn Pex B is designed to be expanded and use the same fittings as Uponor PEX A.
You can direct join ZURN to UPONOR.

ZURN PEX B can also be crimp fitted like all the other manufacturers' PEX B but that results in flow restrictions. I would make crimp fitted PEX brands an alternate choice.

Zurn PEX B has the highest burst pressure ratings , higher than Uponor PEX A. Also has a 20 year warranty versus 10 for Uponor PEX A.

Uponor PEX A is more flexible if you have a tight radius.

I would rank in this order:
-ZURN PEX B expanded
-Uponor PEX A expanded
-All of the PEX B that are crimp fitted.
-PEX C.

Found the Zurn rep.