Inconsistent Quotes ...

[jakeandoy]

Hi folks!

I really hope you guys can help me make sense of this, because I'm lost. I was hoping multiple quotes would reveal a common thread and help me know which way to go, but every company has said something different ...
I'm trying to get AC installed pronto; I live in an area with record heat this year and wildfires burning less than an hour away. The smoke from said fires is blowing in my direction, so having open doors and windows to combat the 100° heat is no longer an option.

Home is approx. 3500sq ft, almost evenly divided between two floors (not including small attic and 700sq ft of unfinished basement. Currently 2 zones & 2 single-stage furnaces, one in basement and 1 on 2nd floor. The one on the 2nd floor is larger than the one in the basement (sorry, don't know the sizes, but I can look that up if it's useful info).

Estimate #1: suggested a 3ton AC on 2nd floor, 2.5 in basement and insisted that the upstairs unit needs to be larger than the basement unit. Also mentioned that my humidifier needs to be moved to the right side of furnace from the back of duct/furnace

Estimate #2: suggested 2 3ton units (at extraordinary cost); didn't mention humidifier

Estimate #3: suggested 2 2.5 ton units, also didn't mention humidifier.

:gah: At this point, since no one has suggested the same approach, I'm not sure which direction to go in. Anyone have any thoughts on the matter?

TIA.

[Gunnery Sergeant Hartman]

Which contractor took the time to address your needs?

Who seems the most professional and trustworthy to do a quality job?

Maybe you need another bid from a company that neighbors or friends recommend...

[jakeandoy]

I'm not so much asking WHO I should go with as I'm asking which size units make the most sense given my setup/situation. The question "Who seems the most professional and trustworthy to do a quality job?" cannot be answered until I have a better idea of who had the better idea as to what size units I should be buying. As a layman, being able to interpret what contractors say is not always an easy or cut and dry thing. MOST times I've had to deal with contractors, they'll ALL say/do something that "makes sense" and ALL say/do something I consider unprofessional/potentially skeevy/doesn't sit right with me. So if you're telling me to go with my gut, thanks, but it's apparently not quite enough this time around. So essentially, I don't KNOW who's addressing my needs, because no one has been consistent in telling me what my needs are. If no one agrees with the correct approach, how can I determine who is and is not trustworthy?

Also, this is a time-sensitive issue (as I explained above) and health issues are on the line. In an area with *record* temps right now, most other companies are scheduling estimates 4 and 5 weeks out, so getting another estimate is likely not an option. So if anyone can speak directly to the question above, it would be greatly appreciated.

[btuhack]

Size? there's a systematic/scientific method called ACCA Manual J that accounts for weather, construction components, infiltration, and interior gains. Having that done might produce the same capacity as one of the existing guesses, but it would be the clinical approach.

Duct work is another issue. Will an existing heating duct system be adequate for the function of A/C which requires higher volumes? It might, or you may become a lifer here if not address before hand. "Manual D" is the correct approach to duct design.

Keep in mind that doing both things, or using a contractor that uses those methods will surely weed out the low bids.

[second opinion]

Post you location and there will probably be someone in your area on this sight that can help.

There is a dealer locator but it may still be down.

Load calculations for your home is the only way to get it right

[Mr Bill]

Start with a home energy audit, it is the first step in making your home more efficient. An audit can help you assess how much energy your home uses and evaluate what measures you can take to improve efficiency. But remember, audits alone don't save energy. You need to implement the recommended improvements. Then find yourself someone to do a Load calculation Manual J and a Manual D on your home, you need both the home energy audit and the load calculations, one without the other is just throwing dollars out the window. Manual J and a Manual D do you no good if air is escaping, or being drawn into your home.

[jakeandoy]

Post you location and there will probably be someone in your area on this sight that can help.

There is a dealer locator but it may still be down.

Load calculations for your home is the only way to get it right

I'm in Douglas County, south of Denver.

Hey guys, i appreciate that you're trying to get me the absolute best estimate of what my house's cooling needs are, but I'm really just looking for an understanding of which of these three approaches seems most reasonable to you. This isn't exactly a shot in the dark considering they've all either said 2.5 or 3 ton units, and while I realize perfection requires measurements and math, I'm only looking for someone to put forth a bit of logic based on general principals -

-Does the 3ton + 2.5ton solution make sense given the upstairs furnace is larger, or should that not factor into the equation? Is that something done often?
-Is an upstairs unit often larger to mitigate heat loss/attic factors? How common is this?

If there is someone in DougCo who would be available to come out today, I'd certainly be willing and appreciative. Unfortunately, if not, I have to go with the information I currently have, so ...

[vstech]

if your house is leaky, a good humidifier is important, as is sealed ductwork that's outside the building envelope.

high temps with low humidity are easier for an air conditioner to deal with. hot air rises, but outside surface area is key to sizing equipment...
windows leak both radiant energy and convection energy... more needs more a/c/heat...

the MOST important factor in an hvac install is the COMPANY THAT DOES THE WORK!
nothing is more important than correct size, and quality installation.

[Mr Bill]

Jake, lets do it this way, this example is so easy to understand, even a cave man can understand it.

If you take your car to a shop and they install a new motor in it, and they implement all of the latest technology available, to make sure your car runs the most efficient possible and gets the very best gas mileage possible, but if your gas tank leaks, have you really made any progress?

Load Calculation= latest technology available, to make sure your car runs the most efficient possible and gets the very best gas mileage possible.

Energy Audit= if your gas tank leaks, have you really made any progress?

[second opinion]

I'm in Douglas County, south of Denver.

Hey guys, i appreciate that you're trying to get me the absolute best estimate of what my house's cooling needs are, but I'm really just looking for an understanding of which of these three approaches seems most reasonable to you. This isn't exactly a shot in the dark considering they've all either said 2.5 or 3 ton units, and while I realize perfection requires measurements and math, I'm only looking for someone to put forth a bit of logic based on general principals -

-Does the 3ton + 2.5ton solution make sense given the upstairs furnace is larger, or should that not factor into the equation? Is that something done often?
-Is an upstairs unit often larger to mitigate heat loss/attic factors? How common is this?

If there is someone in DougCo who would be available to come out today, I'd certainly be willing and appreciative. Unfortunately, if not, I have to go with the information I currently have, so ...

Type in under search for "darctangent" look at his profile and send him an Email he is close and would probably be able to help you

[2old2rock]

Rushing into it is the WORST choice of all.

[ar_hvac_man]

A complete guess but Id say option one sounds more on track. Heat rises and yes, upstairs ac is often bigger than down

[ar_hvac_man]

I AM NOT saying that is what you should do.

[btuhack]

Equivocator:angel:

[darctangent]

I'm not so much asking WHO I should go with as I'm asking which size units make the most sense given my setup/situation. The question "Who seems the most professional and trustworthy to do a quality job?" cannot be answered until I have a better idea of who had the better idea as to what size units I should be buying.

We cannot advise you in the level of detail you are looking for from the vantage point of this forum. At least not in regard to the system you should pick. HVAC is more complicated than you might imagine. The well trained among us look at a structure in ways that the layman (or the unskilled contractor) will always struggle to understand. To put a face on what I'm talking about, consider the following:

1) square footage of the home doesn't matter, but the size and orientation of your windows does.

2) I care very little what brand you buy (they all work pretty well) , but I care a great deal about the design of you ducts, because they often don't work that well.

3) bigger equipment often won't cool any better because distribution often trumps capacity.

4) Everybody looks at the size of the system, few people look to reduce the "heat load" of the home, at Mr. Bill pointed out. Why get a bigger system when you can make the house better instead? When you make the "thermal envelope" of the home smaller,tighter, better, your AC/furnace seems "bigger" even though it's not.


As a layman, being able to interpret what contractors say is not always an easy or cut and dry thing. MOST times I've had to deal with contractors, they'll ALL say/do something that "makes sense" and ALL say/do something I consider unprofessional/potentially skeevy/doesn't sit right with me. So if you're telling me to go with my gut, thanks, but it's apparently not quite enough this time around. So essentially, I don't KNOW who's addressing my needs, because no one has been consistent in telling me what my needs are. If no one agrees with the correct approach, how can I determine who is and is not trustworthy?

You need an education in the way things work, and you can't get that overnight.





Also, this is a time-sensitive issue (as I explained above) and health issues are on the line. In an area with *record* temps right now, most other companies are scheduling estimates 4 and 5 weeks out, so getting another estimate is likely not an option. So if anyone can speak directly to the question above, it would be greatly appreciated.

I suggest you slow down. Get some window units so you can sleep at night and get a better system installed by a good-to-great contractor when they have time to do the job right. Do it right, or do it twice.


I'm in Douglas County, south of Denver.

Hey guys, i appreciate that you're trying to get me the absolute best estimate of what my house's cooling needs are, but I'm really just looking for an understanding of which of these three approaches seems most reasonable to you. This isn't exactly a shot in the dark considering they've all either said 2.5 or 3 ton units, and while I realize perfection requires measurements and math, I'm only looking for someone to put forth a bit of logic based on general principals -

-Does the 3ton + 2.5ton solution make sense given the upstairs furnace is larger, or should that not factor into the equation? Is that something done often?
-Is an upstairs unit often larger to mitigate heat loss/attic factors? How common is this?

If there is someone in DougCo who would be available to come out today, I'd certainly be willing and appreciative. Unfortunately, if not, I have to go with the information I currently have, so ...




Rushing into it is the WORST choice of all.

Agreed.

[jpsmith1cm]

jakeandoy,

I can't help but :hijacked: a little, here.

Would your user name be a reference to The Dark Tower series of novels?

[Six]

He ran off.

Im curious as to what's the average post count added to a thread AFTER the HO has split forever or the tech has figured our the issue on his own.

My guess is 3