First post here - great forum, thanks to all you pros/experts helping out!
I bought this 1946 home a few years ago, my first home. It has no A/C because as folks in the SF bay area know - you don't need A/C here (HAH!). My first summer it was over 90F in my house for a couple of days and I decided A/C is critical (I'm from Miami where A/C = life). I ended up replacing the 20yr furnace with a complete 4 Ton Trane 14XLi setup reusing my existing ducts etc but adding a return and one vent in the kitchen (which had none). I have a lot of complaints and problems but I'll save the rant for anyone who wants to pull it out of me. What I'm hoping for is help addressing my electric bill, which is HUGE, and a warm-room cold-room issue, and about 17 times less important is the ridiculous amount of wind-noise coming out of my (newly installed) kitchen A/C vent which is very close to the assembly in the attic.
The state of things. I have plenty of windows on my southern exposure - all are reasonably new double-paned gas filled UV tinted windows (some framed in aluminum, some in plastic). Most of the house has an attic. Most of the vents are flexible insulated and hanging from the roof, some are bent hard enough that I wonder if the duct inside the insulation is somewhat blocked form being bent constrained. From the attic I can see the shake-shingles and the roofing nails etc. There is about 2" of blown-insulation scattered around the attic floor. The largest room, a recentish addition, has no attic and a high ceiling - this room has two 10 or 12" square vents with huge ducts connected to them (they are both vents, not returns) - this room is always the coldest in the house. The master BR runs hot in the summer and the study (on the north-west corner of the house) runs way hot in summer and way cold in winter. I have tall trees on the east side of my home and get very little sun from there, moderate sun from the south, and the NW corner gets a lot of sun in the late afternoon. The master BR has two tiny vents (4" ducts) and the study (NW) has a single small vent (4" duct); the study is almost directly below the attic-unit.
I hope I provided enough, and not to much info. I'm happy to crawl/measure/smell to get more data if that helps.
Thanks in advance for any advice you would offer.
old house, new AC, frustrated HO
oh yeah - 2000 sq ft house.
I don't beleive you can evaluate your problem Accurately over the internet. There are so many things to concider. I would want to make sure the new A/C is installed properly and all readings normal before I dove into such a situation you describe. Old houses where only sized for heating. So I suspect this could be some of your problem, but there are a few tests that should be run.
What did the installing company have to say?
I should point out that the system cools my house quickly and as cold as I want and is as effective at heating (though neither evenly), I want to get it working more energy efficiently and more balanced across rooms. After a few hours of reading related threads on this site I realize I am a long long ways away from figuring this out myself while I'm not looking for a change in trade.
I haven't contacted my HVAC installer because they screwed up the initial install (oil and water leak - half the ceiling replaced after weeks of complaining) and the repair work they did on that original install left something to be desired (water leak resulting in replacement of the same 1/2 ceiling again the following summer). I got a referral from Home Depot to a local company that's been in business near me for decades (not sure if the forum rules allow bad-naming so you can ask me and I'll tell you). They were easy on the way into my wallet but poor once they got in. I think they way oversold me and failed to give me appropriate guidance. Which brings me to why I'm here - plenty of folks who seem reasonable.
Given the long list of typical shortcomings in my system I'm hoping to get guidance on what are the ones that will get me most bang for my time and money - that may very well be unreasonable to answer remotely in which case I will need to find someone else locally.
Generally speaking, the contractors who subcontract work from Homedepot, Sears and the like are those who agreed to perform the work at the very lowest prices so Homedepot and Sears could make the profit. You can be sure that even if you think Homedepot just made a referral that money was probably exchanged between them or they have an agreement. Those agreements are always in favor of the chain not the smaller contractor. Therefore, the contractor has to be in and out of the job as fast as possible or they don't make money.
Higher quality contractors don't work for the Big chain stores. I doubt that you will get any satification from your current contractor. I would not want them back after the mess they already made.
So, you are probably in a situtation where you are going to have to pay twice and hire a quality contractor. Don't be suprised to learn that there are more things that were not done correctly or short-cuts that were taken when the new contractor has a look at the installation.
first, add more insulation into the attic!!
sounds like you have basic house construction issues, as well as no ducting design --
you spent big $$ because of 2 days of 90F?
probably big bills are due to lack of insulation, lots of infiltration, oversized unit, poor ductwork which is probably leaking, lack of shade -- alum window frames = alum is an excellent conductor of heat or electricity.
I am sure they did a Manual J heat load calculation, right? If they did they would have caught the building construction issues if they exist.
Then using the information from the Manual J calculation they calculated the duct sizes as well, right?
>first, add more insulation into the attic!!
Am I better off putting the insulation under the roof or ontop of the ceiling. I the roof is shake and I can see the bottom of the shake from the attic.
>you spent big $$ because of 2 days of 90F?
I had been living in the area for a few years and saw how poorly my home handled a warm day and decided that AC is a requirement here as it is in my home town. In wasn't clear in my previous posts but that was not a particularly hot day for the area and the temp. in my home was way higher than outside; there are three or so months a year where the daily high is in the 90s and that would've made the inside of my home 100+. I think I could've probably gotten a smaller system and spent the difference on overall quality (duct upgrades, insulation improvements, ...). I thought I chose a quality firm as they had long standing and bid right in the middle of the five bids I got.
> I am sure they did a Manual J heat load calculation, right?
As you guessed they filled out an order form based on sqare footage and scheduled an installation, that was the end of that. I should've done as much research on the craft as I did on the price.
Did they get a permit and have an inspection?
>Did they get a permit and have an inspection?
Yep though the inspector only looked at the unit outside the house, he never came in side - I got the permit closed. Permit is listed for "replace furnace and install A/C."
So the inspector never went inside to look at the new furnace that was replaced? Really?
What city in the San Francisco area do you live in? I lived in San Jose for 25-years.
Perhaps the inspector is afraid Homedepot will take away his discount card. I actually saw that happen years ago with Montgomery Wards.
happygolucky,check out http://www.nationalcomfortinstitute.com & do a contractor search.
The contractors who have recieved this training in your area specialize in correcting problems like yours.
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