AC Help in Florida - 5 DIfferent Recommendations

[Tommy knocker]

Inverter technology has been out for years and is probably more reliable than a recip or scroll compressor. Plus parts will be under warranty for 10 years and if someone is gonna pay big bucks for a top of the line system they probably will opt for a 10yr labor plan as well

It should be fantastic I admit. And it will have a good warranty. BUT. Been to 2 classes, needed continuing Ed hrs, on these things. NO WAY I'm putting my customers in bed with this. Oh ya I just installed a "warranty" coil last week. Been waiting on it for 2 1/2 months. It's not just the inverter that gives me pause. Y'all sling em for a couple years and see how they do. I hope they are fantastic. I'm gonna let your customers test em if that's OK.

[teddy bear]

With all due respect, in my profession I deal with Facts, if it calls for a number 2 widget, that's what it gets. I did not realize this was as much "Art" and some "Science". W

The infiltration numbers are somewhere in the attached reports. Would the "fresh air ventilation recommendation" come from all the contractors or just the guys doing the energy audit?

Attachment 316681Attachment 316691

Florida code, ASHRAE and others suggest .2 ach when occupied. The blower door test shows .25 ACh on with an average wind and average cold weather conditions. In calm wind and moderate summer weather expect much less infiltration. Most a/c contractors say nothing. They know that the fresh air disscusion complicates the bid. If you do not care, do not expect anyone to mention it.
I brought it up because, I sell ventilation/humidity control equipment.
A fresh air change in 4-5 hours purges indoor pollutants and renew oxygen. The problem is that most a/c can not maintain <50%RH when the outdoor dew points are +55^F and low/no cooling loads without a whole house dehumidifier.
That is why it is not mentioned.How good do you want your home tobe?
Regards TB

[dan sw fl]

There was nothing "FREE" about the energy report. I paid for it.

Describe your windows and I'll tell you which one knows something about Manual J calc.

One of them totally lost..!

[jtrammel]

The infiltration rate that the blower door test came up with was not the infiltration rate that he used for the manual j you posted and the infiltration load represents 35% of your cooling load.

[dan sw fl]

Inverter technology has been out for years and is probably more reliable than a recip or scroll compressor. Plus parts will be under warranty for 10 years and if someone is gonna pay big bucks for a top of the line system they probably will opt for a 10yr labor plan as well

IT probably dates back to the early 80's ( u know _ the LAST Century).

[scooterfj62]

IF you did zoning with a single system, I'd go with a 4 ton unless it was an inverter drive like a Carrier Greenspeed.

The systems they quoted were not the Greenspeed. They quoted 25HNB660A003,FV4CNB006T00,CE0501N05 from Carrier and ASZC160601B, MBVC2000AA-1A, HKT-5, TX5N4 from Amana. The 5 ton Greenspeed is crazy expensive and when you add up the cost for the zoning equipment and changing some of the duct work, you lose the cost benefit of a single system vs. 2 systems. (initial purchase) So unless it is just the cats meow and significantly more efficient and effective, I am not sure its the way to go.

Florida code, ASHRAE and others suggest .2 ach when occupied. The blower door test shows .25 ACh on with an average wind and average cold weather conditions. I brought it up because, I sell ventilation/humidity control equipment. That is why it is not mentioned. How good do you want your home tobe? Regards TB

Not sure what all that means, but we want the house to be good, not necessarily perfect - if there is such a thing. But we also have a budget to consider and 1st priority is repairing/sealing the ducts, sealing the holes found between the ceiling and the attic and adding additional insulation. 2nd priority is obviously replacing the current systems.

Describe your windows and I'll tell you which one knows something about Manual J calc.

One of them totally lost..!

95% of the windows are double pain but not low e. We also have 6 doors that have 19 1/2 x 64" glass cut outs in them that are not double pain. Surprisingly we only have 2 windows on the south side of the house, that either are not under at least a 12" overhang, porch, etc. or shaded by trees.

[teddy bear]

The

Not sure what all that means, but we want the house to be good, not necessarily perfect - if there is such a thing. But we also have a budget to consider and 1st priority is repairing/sealing the ducts, sealing the holes found between the ceiling and the attic and adding additional insulation. 2nd priority is obviously replacing the current systems.

.

The blower door info says your home will not get enough fresh air unless the wind is blowing. Homes tend to leak less than blower door test indicate.
Putting a single small whole house ventilating dehumidifier in your home gets you minimal fresh filtered air during calm weather and near perfect humidity control. If you have occupants with any sensitivity to indoor air quality issues, it's important. If you want to have excellent comfort concerning humidity issues, it's important.

WHVDEH will not cost as much as a VS speed a/c which will not get you fresh air during calm weather or <50%RH during high outdoor dew points and low/no cooling loads.
To your credit, you are a concern home owner. Keep us posted on how this all works out.
Regards TB

[scooterfj62]

If you want to have excellent comfort concerning humidity issues, it's important. To your credit, you are a concern home owner. Keep us posted on how this all works out.Regards TB

Thanks for the compliment, as for the WHVDEH system, if we stay with split system, does that mean we would need 2 of these units or only need to install on upstairs system where humidity is higher and. Also if it matters, all the bedrooms are upstairs and living is downstairs, we also have a couple of large dogs that go out into the back yard quite a bit, letting in fresh air.

[dan sw fl]

95% of the windows are double pain but not low e. We also have 6 doors that have 19 1/2 x 64" glass cut outs in them that are not double pain. Surprisingly we only have 2 windows on the south side of the house, that either are not under at least a 12" overhang, porch, etc. or shaded by trees.

You did not mention anything about the MOST IMPORTANT Parameter in sizing FLorida A/C units.

[scooterfj62]

You did not mention anything about the MOST IMPORTANT Parameter in sizing FLorida A/C units.

I am sorry, did I miss something in your question about the windows? You mentioned that one of the Man J's didn't take something in to account and got it wrong.

[dan sw fl]

I am sorry, did I miss something in your question about the windows? You mentioned that one of the Man J's didn't take something in to account and
got it wrong.

The amount of tinting is measured as S OLAR H EAT G AIN C OEFFICIENT ( S.H.G.C.).

http://www.efficientwindows.org/shgc.cfm

CLEAR = 0.87

MEDIUM = 0.55

http://www.efficientwindows.org/glazing_.cfm?id=5

HEAVY < 0.30 may result in a Light Transmittance which provide such low outdoor lighting resulting in a "disturbingly dark" room even on a clear day

http://www.efficientwindows.org/city...dtype=WN&id=66

[udarrell]

If you live in the cold North, you need low-e windows that allow the winter solar heat to enter & then keep that interior radiated heat from passing back through the window pane.

On clear sunny days my furnace seldom cycles even on cold days; At 70-F indoors the design temp-difference I use is 83-F; Lacrosse, WI 99% Design is -13-F below zero. I have a 60,000-Btuh Input, 97% propane furnace that has no problem holding the design temp; - go-figure...

I only have two double pane low-e windows on the south side; one upstairs & one downstairs.

However, I have storm windows on all the other windows &, storms on the three doors.

Tight storm windows provide a u-value about equal to a double pane window at a fraction of the cost; of course they won't be low-e.

In my northern area replacing windows won't have a reasonable payback period, so in the North, look at all the other options before spending the big bucks, - unless your windows have to be replaced for other important reasons...

[scooterfj62]

The amount of tinting is measured as S OLAR H EAT G AIN C OEFFICIENT ( S.H.G.C.).

No tinting on any of the windows, that I am aware of. Was also told by the certified energy surveyor that due to the amount of shading, overhangs, porches and orientation of the house, we only need to tint 2 windows.