New System Quote...question

[kdean1]

Hello. Thanks so much. Yes he did do a bunch of measurements. And he looked at our usage via the utility bills and also the Tesla app which shows what we're using on really hot days (we get to 100+ a lot and my wife works at home so I believe we use a lot of cooling). We had a 4ton unit in the house when it was built and it def is not up to the task on hot days (works all day and never turns off). I have not signed anything. But this is the third estimate I got. The first two were for inferior equipment (based on research) and would not be able to run off my batteries. One estimate was $!!! I have no idea what is fair. I didn't think this seemed very high given what I have heard asking others who moved to heat pump and got a new air handler (but kept old ducts and plenum).

Once again - PRICING IS NOT ALLOWED!!!!

[kdean1]

I was told that the ductwork was sized for a 5ton unit but the builder put a 4ton in it?? I don't know how to verify this. As for the equipment, they said their "supplier has one of each [air handler and outdoor unit] in stock for an 8/3 install." We don't have large parties but we do have a lot of south-facing windows and what seems to me to be a lot of heat soak into the bedrooms above the garage, which gets absolutely scorching in the summer. I was originally just going to replace the rusted out coil in the attic but as I started getting estimates for that my air handler began to show signs of failure (it wouldn't turn on randomly and that would cause my lines to freeze). So I started looking into a whole new system. The heat pump wasn't given as an option until I brought it up becuase of the rebate I saw and after talking to Tesla about getting the compressor put into the battery backup circuit. They are the ones who suggested the heat pump option and looking into it I thought it seemed good for my climate and use case. The other estimates were given using (iirc) Lennox brand products that were cheaper than the TRANE to buy stand alone...that's what made me think they were inferior.

Bonus rooms (room over garage) are often undersupplied by the duct system because they are distant from the fan coil and duct routing is long and has many turns. Bigger equipment than what was there before will make matters worse by cooling the other areas more rapidly and satisfying the thermostat sooner.

The problem may very well be the old ducts and plenum rather than the equipment.

We often down-size equipment because the old equipment was too big. The result is quieter operation, better distribution, better comfort, and reduced energy consumption.

[dan sw fl]

I was told that the ductwork was sized for a 5-ton unit but the builder put a 4ton in it??

I don't know how to verify this.

As for the equipment, they said their "supplier has one of each [air handler and outdoor unit] in stock for an 8/3 install.

We don't have large parties but
we do have a lot of south-facing windows
and what seems to me to be a lot of heat soak into the bedrooms above the garage,
which gets absolutely scorching in the summer.

1. Measure the Total External Static Pressure (T.E.S.P.)
2. Measure the Air Handling Unit BLOWER MOTOR CURRENT.

https://www.trutechtools.com/static-pressure-test.html

https://www.rses.org/assets/rses_jou...114_Static.pdf

If ESP > 0.62" for a 4-Ton {1,500 CFM},
5-ton {1,900 CFM} may result in ESP > 1.0"

E.S.P. > 1.0" may significantly reduce Blower Motor life.
i.e. ___ Let say, Normal Life = ~ 12 years
_.. High Current Motor Life = ~ 4 years

High Current = > 85% of Motor HP Rating