New Central Air

Mikey081057

After 15 years (me only 4 1/2 years here) I decided to replace my AC system. I replaced it before it failed, The old system was by Rheem and by all accounts lived a good life here in SWFL where you use AC all year round.

Multiple installers I know personally recommend TRANE and I had some local TRANE dealers quote and spec the job.

Closed the deal on Friday and the guys picked up the stuff and installed yesterday (Monday).

As you could imagine A/C biz is very competitive down here and there are lotsa good companies with very good reputations to chose from, so you go from there and pick the best deal on comparative equipment.

They basically replaced and up-sized all the duct work (plenum/returns and supplies) so all new nice clean duct work. Which is now even better insulated and efficient than 15 years ago. The new air handler has a variable speed blower. Very quiet... You can't hear it running inside anymore. You can only feel it running...

The system goes from an old SEER of 11 to new of 17 which should provide some savings.

I have a pretty good baseline of power consumption thru my electric company. I keep the house at 76* all year when occupied and the T-stat has a feature that once I go out side of a 5 mile (user programmable) it goes to the fall back temp of 80* (also user programmable).

The new system with R410-a refrigerant does not get coil temps as low as the old R20 but you can't use that anymore... The result is you get a little bit higher indoor humidity level ( like from 40 to now 43%) but it is still way in to the comfortable zone.

Here is the energy usage baseline: The bar is consumption and the lines are daily temps. (Hi Avg Low) What's cool is that when you are in the app you can hover over each of the graph points and get temps, consumption, and cost per day)



I'm going to watch it to see if there is really a difference.

afterburnt

How much did it set you back?

polrbehr

Good call on Trane. When I was considering CAC years ago, a builder who was then a client of mine used Trane on every project he did, and recommended them without
hesitation. The ONLY reason I ended up going with Lennox? They had a promo going with 0% interest for 3 years/$0 down, that was the determining factor - well, OK, Lennox had a really good rep too, and I've had 12 (almost) trouble-free years with
ours.

motorhead43026

It's not hard to stop a Trane.

Hopefully you will have years of trouble free service.

Mikey081057

afterburnt wrote: »

How much did it set you back?

All in with all the new duct work $5400 new breakers and surge protection. With 3 years of scheduled maintenance included.... ($450 app value)

Mikey081057

polrbehr wrote: »

Good call on Trane. When I was considering CAC years ago, a builder who was then a client of mine used Trane on every project he did, and recommended them without
hesitation. The ONLY reason I ended up going with Lennox? They had a promo going with 0% interest for 3 years/$0 down, that was the determining factor - well, OK, Lennox had a really good rep too, and I've had 12 (almost) trouble-free years with
ours.

I had a new(er) Lennox system on my house in NJ and liked it very much.... Very quiet and efficient.

Jimbo18

Our 17-yr. old York is going to have to be replaced next season. Hoping to limp through this year. With this heat (NC), it's struggling to get it as cool as I like it, even at night. I was thinking of getting either of those two brands mentioned above.

Mikey081057

Down here they say 12-15 years is the life expectancy so I don't think your 17 y.o. unit owes you anything.

Pick a manuf. you like and watch for promos and rebates or special financing and pull the trigger then.

I just preferred not to wait for it to fail b/c at 15 yrs I wasn't going to put a dime into it.

hochpt21

We just had to replace the furnace this last winter and went with a Trane also.

The A/C is not far behind, but hoping to get another year or two out of it.

joecoulson

Running a beast of. Carrier unit from 1989. It cools like a beast but not very efficient
Still, only runs half the year and is cheaper than a new 3 ton unit. Amazing build quality.

charley95

Had a Rheem system from 77 in my place and replaced with a York system a few years back. Couldn't complain one bit with the Rheem, it was a hell of a unit other than low efficiency. Are you close to the coast? I thought the salt air ate up the AC units in a short amount of time?

Mikey081057

I'm a couple of miles inland on a cape... I think the salt factor is more with stuff on the water subject to spray... The sun, heat, rain and humidity are the factors here...

They say 12-15 years is the normal life expectancy of central air down here. Plus you use the heck out of them... The duct work and the air handler need to be maintained and disinfected regularly along with the condensate flow to make sure they don't get clogged with phlegm. So for the $150 bucks a year it gets you 2 visits where they spend a good hour + cleaning and checking your system. Helps keep it in tip top operating efficiency too.

My average daily electrical usage for the prior billing period was $6.21 / day
Yesterday was my first full day with the new system and my usage was $4.29. I also used the washer dryer dishwasher and cook top yesterday which is really not a normal day.

My T-stat stays on 76 and I usually don't mess with it when like leaving for a few hours but I do have a fallback set to 80 for when I do leave the house. The stat is bluetooth and knows when my cell phone is outside of the user set radius.

I am going to try and use just the essentials today to see what kind of read I can get.

I am also utilizing a variable speed pump on my pool which runs 9 hr/day and uses app 165 watts to run unless sending water to the roof panels to be heated which is not what happens much in the summer months.

My expectation was to save $1 + per summer day and somewhat less in the "cooler" months.

tonyb

Here's a little tip to keep your A/C - Furnace running good.....do not use those frickin' upgraded filters. They block air flow and make your system work harder. All you need is like a #4 grade filter, anything above that is going to slow down the airflow.

Mikey081057

Agree... and don't play with the registers ... leave them all open and let it flow!

pitdogg2

Mikey081057 wrote: »

Agree... and don't play with the registers ... leave them all open and let it flow!

Not sure I agree with that. Why heat or cool a room or rooms you never open the door to ? For the sake of the argument they do not have returns located in them either.

Mikey081057

I'm talking about A/C not sure how restricting airflow during heat cycles effects efficiency but with A/C if you have a 3.5 ton A/C system sized for a 2000 Sq ft home and you cut off 800 sq. ft of cooling are and only cool 1200 sq ft you are going to create humidity issues because the system will not run enough to remove the humidity. Restricting heat may cause issues with pipes etc. in colder climates.... YMMV

DaveHo

According to the guys who installed my HVAC, registers should be left wide open. The proper way to balance the system is with the use of dampers located as close to the trunk line as possible. Has done wonders in my 2 story house. First floor & second floor temps are within a degree or two even when the temps outside are extreme.

afterburnt

https://woodscomfortsystems.com/articles/issues-caused-closing-vents-unused-rooms

polrbehr

I don't know for sure if this is true or not, but the guys that installed my CAC told me that the system is "balanced" for the amount of openings they installed. IIRC, this is
accomplished at the main trunk, where each individual duct is connected to. They also calculated how many openings (and diameter of ducts) is needed for each room.

The idea is to create temp/humidity levels in each room to be as equal as possible. They even told me that the temps in all areas of the house would be within a degree or two of each other. I never verified that with a thermometer, but every room in the house feels pretty much the same, so I am guessing they did a good job figuring that.

Mikey081057

Yes... size matters... but there are other things like cooking and other heat sources generated by like.... um I dunno audio equipment... that is why I updated some of the duct and trunk sizes during this change. Balancing is key here in FL because of humidity and mold issues.

Mikey081057

Yesterday's usage was down to 43 kWh... About $4 worth of usage. I programmed the T stat to 78* during the day from 8:00 AM and 10:00 PM and down to 76* from 10:00 PM to 8:00 AM. 78 seems comfortable during the day but I like 76 while sleeping. Could this get me under 40 kWh daily and average under $4.00 per day?

Our electricity is charged at $08.5 cents for the first 1000 kWh $12.5 cents /kWh form 1001-1500 and $.12.5 cents from 1501 kWh and up.

I suspect I can keep it in the 8.5 cent / 1000 kWh in the cooler months and am trying to see what I can conserve in the summer months.

rpf65

I tell my customers to set the thermostat where they feel comfortable. Just seems saving $20 or $30 a month isn’t worth it.

Of course this is my opinion, and some will disagree.

tonyb

I keep mine at 70 year round. It feels cool in the summer, and fairly warm in the winter.

Not sure I agree with the registers all wide open either. The cold air returns should all be left open and unblocked though.

In my basement, the registers are in the ceiling, so hot air in the winter only goes down a few feet before rising back up. So winter time I keep the registers closed upstairs. Summer is the opposite, open up stairs and closed downstairs, because obviously cold air sinks.

joecoulson

I will go ahead and say I am an energy ****, we keep it 72-73 in summer (even when 95+ outside) and 75-78 in winter LOL

DaveHo

My parents were always thermostat misers. Freeze in the winter, cook during the summer. To this day my mom still sets the A/C at 78. I start sweating when I walk in the door. I ask her, "Why bother?" I set it where it's comfy, cost be damned. Though with my Nordyne IQ drive system, the electric bill is only about $50-60 a month more than the wintertime. Heat is forced air natural gas. My total energy costs are actually less during the summer months.

joecoulson

Not sure where you live but my summer costs triple my winter ones. Avg 300 during dog days and <$100 winter. Gas heat.

Mikey081057

76-78 is comfortable here in SW FL when you also control the humidity 40 - 44%. If you feel cold in the winter and your humidity is low @ 70* you probably need a humidifier or maint. on your humidifier.

afterburnt

tonyb wrote: »

I keep mine at 70 year round. It feels cool in the summer, and fairly warm in the winter.

Not sure I agree with the registers all wide open either. The cold air returns should all be left open and unblocked though.

In my basement, the registers are in the ceiling, so hot air in the winter only goes down a few feet before rising back up. So winter time I keep the registers closed upstairs. Summer is the opposite, open up stairs and closed downstairs, because obviously cold air sinks.

https://woodscomfortsystems.com/articles/issues-caused-closing-vents-unused-rooms

charley95

Mikey081057 wrote: »

76-78 is comfortable here in SW FL when you also control the humidity 40 - 44%. If you feel cold in the winter and your humidity is low @ 70* you probably need a humidifier or maint. on your humidifier.

I'm just jealous that you live in Florida!

codycatalist

joecoulson wrote: »

Not sure where you live but my summer costs triple my winter ones. Avg 300 during dog days and <$100 winter. Gas heat.

That's about where I am at. Granted I am SURE my place is smaller than yours, not well insulated and an OLD ac.

Summer we keep it at 78, winter we keep it around 75. I keep it at 78 all summer long, I don't go up to 80 when I leave. It gets so hot here that the AC works twice as hard to get that 2 degrees down when I get home from work that it isn't worth it. I save money keeping it at 78 while I am gone.

joecoulson

I do agree with that statement. I used to turn it up a few degrees when leaving for half a day, but it runs continuously for 6+ hours when I get back home and turn it down. Not worth it.

My house really is pretty small comparatively lol