Any interest in indoor air quality? How many occupants and how air tight is the construction? Regards TB
I am not in the HVAC industry, but I like to learn a bit about all my major purchases etc.. The more I start to read about this the more intrigued I become, but also realize how much there is to know.
I am about to build a new home in the New Orleans (Kenner) area. It will be 3,000 sqft living, 2 story with an unfinished 3rd floor, and a very large attached 2 car garage. The house is French Provencial (a big square), not spread out with wings and hallways etc. if that has any relevance.
By default, my builder is including 6 Tons (2 units), 13 Seer, Goodman R410A. I have no obligation to stay with that configuration. I completely trust my builder with many aspects of the construction, but I know he is not a HVAC expert. Based on my reading, a few key points stand out to me that I would like to explore...
1) People here overwhelmingly agree that most failures are due to poor installs rather than faulty equipment....I previously had no idea there was so much behind an install. Would someone please elaborate?
2) Some reading implies that mosts units are really not that much different (as far as reliability and quality go) because the "guts" of the different brand units are often the same. So a less expensive unit like Goodman may not really be an inferior product. I am really struggling with the whole "Goodman" thing. I really don't like to settle for an inferior product, however some suggest the bashing is actually for reasons other than quality.
3) I could really use some basic recommendations for my home.
thanks
Last edited by BayChamp; 10-13-2008 at 02:39 PM. Reason: changed one word
Any interest in indoor air quality? How many occupants and how air tight is the construction? Regards TB
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"
How did they arrive at sizing? Even for hot NO, 6 tons for 3000 sq ft new construction is a flag for me. Bigger isn't better, bigger means humidity issues.
Goodman is basic equipment, like the builder lines from all the manufacturers. Put in right, it would be fine. Want better stuff, more features, quieter for example, Goodman's Amana line is top notch stuff and can compete with much of the industry's top goodies. Your choice!
If you stay with Goodman, I would step up from the builders grade 13 SEER to at least the 14 SEER. This will provide lower operating costs due to higher EER (Energy Efficiency Ratio).
www.GoodmanMFG.com
Are you using heat pumps for heat?
Was a Manual J heat gain/loss calc done on the home?
Good luck.
Ok, I'm really confused now...I thought there was "Amana" and "Goodman Amana", which I thought may also be labeled as "Distinctions".
Is there in fact "Goodman", "Goodman Amana", "Amana Distinctions", and "Amana"? I don't think I have that right.
I believe my builder did call it "Goodman Amana" though.
"Goodman is basic equipment, like the builder lines from all the manufacturers. Put in right, it would be fine. Want better stuff, more features, quieter for example, Goodman's Amana line is top notch stuff and can compete with much of the industry's top goodies. Your choice!"
Goodman (basic)
Amana (premium)
Amana Distinctions (basic, relabeled Goodman)
Did you interview with the heating contractor and ask there ideas on what is availiable? This would give you the chance to meet them and get firsthand knowledgeas to what they are trying to do for you and the new house. There are many options that need to be explored and this is a good starting place.
As said above 6 tons seems alot but I don't live there and maybe your house has alot of windows. Ask if a manual J load calculation was done on the house and what the results are. If they are just guessing on size then what else may they guess on during construction? Duct sizing is also very critical and should be well thought out.
These are the type of things that I would worry about more than what brand is being installed. After you find a company that will help you with these then you should talk brand of equipment and what will fill your needs from the calculations done.
Enjoy the building process. I personaly think it is alot of fun although a little stressfull.
Its a good Life!
Ok,
So there are really just two. Since my builder called it "Goodman Amana" he is likely referring to "Distinctions" or just "Goodman" which is one in the same.
So 6 tons sounds like too much? What is your best guess then? A manual J was not done on my home as it has not been built yet, however we are using plans from existing homes (which we altered somewhat) so I don't know if it was done there.
So far I was only quoted for standard fiberglass or cellulose insulation. I haven't investigated the spray on yet. I would love some input on that but if this is an inappropriate place for it, I understand.
A manual J should be done off the final set of blueprints. We do them all the time for the houses we do. The house does not need to be built yet but the windows, insulation etc.. need to be picked out so an accurate calculation can be done.
Its a good Life!
In my honest opinion, some of the best money you can spend on the house will be spray foam insulation. Do the whole house, walls, attic, everything.
R-value is increased, but what really improves performance is infiltration rates are reduced significantly beyond what cellulose or fiberglass can provide.
The money spent will come back to you in spades through the years.
If you go spray foam (do it), the heating and cooling loads required change significantly, it's important to know what path you are taking on this for your conversations with contractors...
OK - there is a catch. With such tight construction, you will need to provide mechanically supplied fresh air, a whole other topic.
I strongly suggest you talk directly with an HVAC subcontractor / contractor. Like you said yourself, your trusted builder is not an HVAC expert. There is alot to learn, as you've come to know. Research in here with the SEARCH button, and talk with a few contractors directly.
The original post said two 3 ton units. How are these set up? Do they alternate back and forth most of the time? That's how the bank of AC units here at work operate only working together at full capacity during extreme hot weather but I don't know if that's standard procedure with residential. It wasn't explicitly stated but I guess another option with two units would be zoning. I'm guessing the upstairs gets a lot hotter than downstairs; especially if it's a slab foundation.
Decide on your insulation first.
The better you insulate now, the lower your HVAC operating cost will be.
At 6 tons, they just used a rule of thumb. And its a bad rule.
The load calc can be done from the prints. Thats how you do them for new construction.
1) The best equipment can sure be screwed up with a poor install. The "install" starts with the system design. If the units are the wrong size you're half way out of the boat to begin with. Especially with a dual heat pump zoning system I'd want to find an expert you feel you can trust to review it.
2) I guess that's endlessly debatable but... Are the 3 ton units a scroll or reciprocating compressor? Do they include a hard start capacitor, an on demand defrost cycle, Thermostatic Expansion Valve, etc.? What are the noise specs? Make sure you're comparing apples to apples when you look at bottom line price.
The SEER numbers are an important guideline but if you read the fine print they all say something like "as high as" or "in certain applications". Look at the coil and air handler combination that's being spec'd and see how it really stacks up with respect to the ARI numbers.
I'm not an expert, just someone that's recently gone through the process and found out how important it is to educate yourself so you can parse what the "experts" are telling you. The local "experts" recommended everything from 3-5 tons for my 2800 sqft house in Seattle. In Seattle we're driven more by the heating side of the equation than the cooling. I don't know about the Big Easy but if heating demands are negligible you my find it more cost effective to do something like a dedicated 18 SEER air conditioning system and fall back on strip heaters for heat.
One thing to consider when choosing is what rebates and tax incentives are available in your area. Typically the incentives go up with the efficiency of the units. Sometimes manufacturers rebates, power company rebates and tax incentives can make top of the line equipment virtually the same cost as the lower SEER units.
One thing that may effect you is two units most likely will only qualify for one rebate. If that's based on calendar year installing a single HP now and a second prior to next summer could mean a big savings. Of course there would be some additional cost but might not be to extreme if the staging was planned. Building in a control system that allows the two units to share the load would overcome some of the concerns about the units being over sized for typical conditions. It would also give you a whole house backup should one of the units require service.
Thanks for the responses. My builder now knows that I am doing my homework.
I think I need to decide for certain on the insulation type before I try to make any more AC decisions.
I did talk to a friend of mine in the industry who is passionate about it. He told me that he often DOES oversize but has the units set up so that only one is being utilized until the other is really required. I believe this may have been mentioned in an earlier response but in different words.
I will be getting a heat load test done. I didn't realize that was calculated from the plans.
thanks
They'd have to be twinned to work as well as he's leading you to believe.
Put the best insulation in your home that you can afford thur out the home, and put good windows in the home too along with the insulation will save you some money on the HVAC side of things when all is considered. and if you don't do anything for indoor air quaility before you move in you may want to atleast have the duct work installed so all you have to do is have a ERV installed when you have funds for it should that be the case will again save you moeny in the scheme of things. When going over your contract with whom ever is doing the work be sure duct sealing and duct insulation is included in the price, and if at all possible stay away from flex duct work if you can, and go with hard duct or it's equivolent.
I've been researching my insulation choices (fiberglass, cellulose, open and closed foam) online...however I find that the vast majority of information out there is from vendors websites. Therefore they are very partial to their own product. If I were to combine different types to save money and still get significant benefit, how would you do it? For example, Closed Cell foam in attic and cellulose in the walls? Are maybe Closed foam in the south and west walls (someone mentioned that to me). Would something like this be a reasonable plan???