How well did your old systems work for you?

Mike stated what I was thinking. I will add that the load calculation can be high or low depending on what numbers he used. If he used 78F for a desired temperature and you like 75f, his numbers will be too small. If you have a lot of shade trees, his numbers may be too big. And so on...

We are within 8 miles of the coast, Charleston is our closest city being only a few miles away.

Sketch is of our house - left is downstairs (AGAR has its own 1.5 ton system), right is upstairs, 20x24 of it though is open to the downstairs and not actual additional rooms.

Not 100% sure on cooling, the room with 20ft ceilings open to the upstairs level is always quite warm and I would say not cooling well. We have only owned house since December though, so we haven't had much weather that warranted cooling and with both the upstairs and downstairs systems completely dead at this point I can't do much with them.

The systems really didn't work that great, very very costly to heat and cool (Even just to heat to 68 degrees) compared to our previous home of similar size, the only difference between this house and previous house was layout...previous house was traditional floor plan, not open concept, current house very open with great room w/ 20ft ceilings open to 1st and 2nd floor.

Did they perform the Manual J load calculations? That is the industries accepted way of sizing equipment properly.

Yes, at least I assume that is what the guy was doing - he measured our entire house, and went around looking at air returns, etc etc...he was there for 3 hours?

But like I said he came up with 3.93 and 2.75 or something like that, and unfortunately the higher SEER systems don't come in half tonnage.

The equipment output BTU must match or slightly higher. It is complicated. I am at HVAC-consult.com

The reason they don't come in half ton sizing is because they are two stage.

With two stage equipment you need two stage blowers and two stage stats. So the indoor equipment should be two stage also.

all good equipment...it is a waste to purchase an outside Infinity condenser without best matching Infinity air handler and the ubiquitous Infinity controller. I like the sizing from the AmStd dealer best. If your load calculations are correct, i don't understand why Carrier dealer is quoting a 3 ton for downstairs when you have 3 1/2 ton existing ( load calculator indicates 3.93 load ). I personally think AmStd HPs hold up better in a coastal environment. And I can say unequivocally Charleston area is tough on HVAC. I suggest the 824 thermostat over the 624. And if you don't already have one, add pleated filter media cabinets for both systems.

IMO

American Standard condensers are all aluminum I doubt that condenser coil lasts much longer than 10-12 years best case scenario. You need to buy a unit that is rated for being installed in a coastal location or you will regret it in short order.

The summer design temperature for Charleston SC is 92 degrees. Your house is effectively 3500 sq feet when you account for the open area going from the first to the second floor. Even at that size I have my doubts about requiring 7 tons of cooling.

Your current systems seemed backwards. The upper floor about the same size as the lower floor yet the 3.5 ton condenser is downstairs and the 2.5 ton condenser is upstairs.

Who did the load calculation? Is the American Standard dealer proposing replacing the 2.5 ton condenser with a 4 ton condenser? Is he going to increase the sizes of the duct work in the attic to accommodate the increase in air flow?

I think the 4 ton unit is supposed to go downstairs because that's our bigger unit currently and has the larger air returns. Though I think they would still have to modify the air returns downstairs to put in a 4 ton because we have a 20x25 and a 14x20 downstairs currently?

I had another guy come this morning and he suggested just replacing just the condensers with the minimum 14 SEER, and not touching the air handlers or coil because they're fine right now. He said obviously they would check the indoor coil, but why replace it if it's not bad. Obviously this would be a cheaper option, but what are the pros and cons of this?

He also confirmed that the guy that came out caused the leak in our upstairs unit (it was fine until he got there), which is what I thought :-(

that 14 x 20 return should be enlarged or perhaps add another return...you want a matched system both condenser and air handler...

IMO

I had another guy come this morning and he suggested just replacing just the condensers with the minimum 14 SEER, and not touching the air handlers or coil because they're fine right now. what are the pros and cons of this?

This option is more or less retrofit. Nothing wrong about it in an of itself, it can work if the work is done by a competent 'skilled' person. Is this other guy doing the work or subbing it out? Will this other guy stand behind it and not blow with the wind?

Even if everything is done right you are putting new equipment with older equipment. So you may be spending more money in short order to repair other parts of your aging equipment.

With that said, you could put in new everything and still have problems due to an assortment of things.

If the right manufacturer is chosen for the condensers your warranty will be no better or worse except it will only cover the condenser that was replaced. This term should be at least 10 year parts.

I have done it successfully and continue to offer it as an option with conditions attached to it (when it's feasible to do so). If the company you are using are using installers or subs to do the work I wouldn't do it. It will (most likely) lead to untold problems and they will most likely blame it on the older equipment.

I would still choose a coastal approved condenser, if I were you though.

Unfortunitly there are a lot of dishonest HVAC contractors running around. Most states do not require testing or a license. Sost of the towns just require a retail license to operate. The majority of inspectors are political jobs and the inspector does not ned to know anything. That is why I started HVAC-consult.com. The new units today require larger indoor coils to operate correctly. There are two type of heat removal. Sensible and Latent. Sensible heat is the dropping of the air temp across the indoor coil. Latent heat removal is the the drop in humidity. If the coil inside is not sized correctly the humidity remains high. Some manufacturers will not warranty performance unless it is a matched system.

If they did load calculations correctly they can tell what the Sensible and latent loads are and what the equipment match will provide. Using old indoor equipment with new condensing units is just guessing because they were not manufactured at the same time and performance can not be tested. I have got to invest in a new keyboard!

If the 7 tons of cooling is too much, then is 6 tons good? I'm not very knowledgeable on how this exactly all works, but I know a 16 SEER system I cannot get in .5 ton increments, so we won't be able to replace our 2.5 ton and 3.5 ton systems with the equivalent, so do we go up on one and down on another (Two 3-Ton systems)? Go down on both (A 2-Ton and a 3-Ton)?

Or is it better to just go with the least costly quote we received of $11k for 14 SEER single stage systems with matching air handlers that are equivalent of what we currently have?

"I think the 4 ton unit is supposed to go downstairs because that's our bigger unit currently and has the larger air returns."

The proposal doesn't state which floor is getting the new equipment? You must have a lot of south facing glass on the first floor in order to warrant using a 4 ton condenser downstairs versus the 3 ton condenser upstairs. Have the contractor explain the load calculation to you and see if it makes sense.

"I had another guy come this morning and he suggested just replacing just the condensers with the minimum 14 SEER, and not touching the air handlers or coil ..."

How old is the current equipment? Does it use R22 refrigerant? I would not be comfortable reusing a coil while changing the refrigerant from R22 to R410. If you plan to be in this house 5-10 years then I suggest you replace everything. When you mismatch new equipment with old you will not achieve 14 SEER.

The equipment is from 2000 based on model number, but it uses Puron which I believe is R22?

We do plan to be here a while, so I want to be happy with whatever we select which is maybe why I am so confused. I got a lot of quotes thinking there'd be a common theme amongst them, but boy was I wrong.

The only contractor that did the load calculation is also the only one talking about taking us down a ton, so he would put a 3 ton downstairs, and a 2 ton upstairs he said (maybe go with a 3 upstairs, but that was a maybe). He said he'd rather be undersized then over. He was offering Bryant equipment though (he also suggested Lennox initially but we found the air handler was too tall to be in the closet), and he was offering single stage condensing units with variable blowers for slightly over $17k which is why I kind of stopped considering him because I feel like that's an awfully high price for that.

Not really sure what I should do at this point. I'm a little perturbed that the guy that came out to do a service call on our one unit essentially made it so we'd have to buy two units. Rethinking about going with them after that (they are the carrier dealer that I talked about above).

7 tons of 2 stage HPs with bottom system having partial 20 ft high ceilings...what is oversized about that?...I want good humidity control and definitely don' want to be undersized in Coastal Carolina.

IMO

Okay, so I just got a text from the other guy, he's stating like $8750 for all new condensing units plus the indoor coils and air handlers. Broan would be the brand. I'm not very familiar with them, but they seem to have similar warranty to the larger name brands.

Obviously they are much cheaper, so now I'm very confused - do we go with bargain basement 14 SEER option which will be single stage, basic Broan systems. Or do we spend almost double at $16k to go with Carrier Infinity + Infinity Systems, or spend $17.9k to go with the American Standard systems.

I guess I'm just not sure what to do, and really everyone keeps telling me this is a fairly harsh environment for HVAC systems, so they only last 10-12 years anyway...so obviously that's why the cheap option looks tempting because $8750 every 10 years is easier to handle than $17k every 10 years. Unless the $17k system would last 15 years then obviously it's not apples to apples.

Sorry for my rambling...Just thinking out loud :)

You are comparing top of the line American Standard and Carrier equipment with some unknown model from Broan. Not exactly a fair price comparison. If you are going to compare equipment by price then compare similar equipment.

Get a written proposal from the Broan dealer and make a determination if he is going to provide a good installation and service. I have no experience with Broan. There is no listed Broan dealer within 100 miles of my zip code in NJ.

Well, I have a quote of the equivalent Carrier system to the Broan, it is $11.5k, so we could go with that. Kind of basic, no bells and whistles option.

I think I'm confused mostly on if the 16 SEER 2 stage, variable speed infinity systems are really worth it, or if they will make our house feel way better or what it gets us? Because it's anywhere from $6-7k more than the 14 SEER options.

Broan is one of about 1/2 dz appliance type names that are licensed to Nortek for HVAC...all I can say is tred very carefully here....you get what you pay for...

IMO

Ugh, the whole get what you pay for thing always gets me...which is where I'm like well I could get an $11k 14 SEER Carrier system, or I could pay barely $1k more and get a 15 SEER, but then for only $4k more I can get more fancy things like 2 stage and variable speed Carrier infinity systems, or I could pay $1k more than that and get the American Standard system...lol

That's where I wonder what gives us the most bang for our buck...I'm reading on the internet that the 2 stage systems are more complicated maintenance-wise, and parts are more costly which potentially leads to more costly repairs down the line?

How near the coast are you? Check your warranty against coil failure due to salt air. The system could fail before you get payback on the higher eff. equipment.

Find an HVAC company that sells York. Usually much better prices.

We are within 8 miles of the coast, the unit is a Coastal unit but I can check to see what that does to the warranty.

Broan and York both use micro channel technology to some extent. It is probably only their lower end product lines if I had to guess. Micro channel is merely a way for the manufacturer to cut costs associated with refrigerant. The systems are critical charged down to the ounce. Means if you lose a mere ounce of refrigerant due to a small leak it won't run right. There are other problems above that.

The Broan unit is salt spray tested at 900 hours but divide that into 24 and you've got a 40 day test. The micro channel coil is all aluminum. 2 speed equipment isn't any harder than single speed if you know what you are doing. That is why you hire a pro. That's your only way forward IMHO.

An all aluminum condenser coil in salt spray environment is a guaranteed leaker in short order. Aluminum doesn't stand up to that kind of abuse.

When you say that is your only way forward, do you mean hiring a professional? So far all of the companies that we have gotten quotes from have been fairly well rated on Angie's list, The brand or product is the only thing that has varied.

Hmmm...I think the Carrier is also Aluminum, I think? :-/

Ok, you have to straighten out a few facts. Aluminum is used by all manufacturer's to one degree or another. You won't find a condenser coil without any aluminum. However, an all aluminum condenser means the refrigerant runs thru aluminum tubing where as a copper & aluminum coil uses copper to run the refrigerant thru.

Almost all manufacturer's use all aluminum evaporator coils today. This coil typically sits indoors in your indoor equipment. It's very easy to get these things mixed up so make sure you are talking about the right piece of equipment.

Finding companies rated on Angie's list is kind of like self promoting for a fee. I think you would be hard pressed to find anyone rated poorly on Angie's list unless they weren't paying $$$ to Angie which is a conflict of interest.

If a company had a bad rating on Angie's list why would they pay Angie money? That is the conflict of interest if you catch my drift. It's not to suggest the positive reviews aren't accurate but one can only wonder what happened to the negative reviews. Who in their right mind is going to pay someone to advertise bad reviews?

Nearly every 3rd party company rater or reviewer is like this and has some conflict of interest in which they charge money to the companies they offer reviews on. Pay some money and get the negative reviews to disappear.

Nothing up my sleeve. PRESTO!

Finally, what did you decide on? Which one you went with? It's been 4 years. Are you happy with your purchase? It would've been nicer if you had updated here. Read all the comments. It was like a movie without a climax. :)