For residential new construction, ducted forced air, HVAC, mid-south location with 90 degree medium-humidity summertime highs, 5 degree wintertime lows (occasionally), long temperate springs and falls.
Natural gas furnace inside, outside heat pump, pump provides heat down to maybe 38 degrees of outside temp.
Carrier? York? Other brands? Add-ons for winter humidification and air cleaning? Controls?
Replies
Many folks recommend picking the HVAC person and taking his/her recommendation.
That is based on the view that there isn't a lot of difference between manufacturers (as opposed to differences between models - there are dogs out there, of course)
New construction generally shouldn't need humidification because of reduced air exchanges
The HVAC folks in my area all pretty much recommend the 5/6" media filters
Youth and Enthusiasm Are No Match
For Age and Treachery
Dont let the high-priced guys tell you Goodman HPs are junk, have installed 3 of them myself with great results (all with Copeland Scroll compressor, a must in my book for any HP). Some of the sheet metal work on the air handlers needed stiffeners added, otherwise good units at 3/4 or less the cost of big name brands.
Honeywell vision pro thermostat
When I was doing research on this, there seemed to be a consensous among HVAC engineers that proper size and installation is much more important than brand name. Even names you've never heard before should work just as well as a name brand, and last just as long.
Name brands have prettier brochures though.
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
"..a consensous among HVAC engineers that proper size and installation is much more important than brand name."
And you can include this HVAC Engineer in that consensus. I have evaluated commercial, light commercial and residential product offerings of most of the "major" manufacturers, and many of the "minors" as well, and find them all to be so similiar as to be mostly indistinguishable. In others word, excluding paint and stickers, they're all the same (comparing apples to apples). Proper selection and installation is critical, brand is trivial. In the event service is required, the more common brands will be more easy, in most cases, to find service/parts for, Lennox being the main exception here.
A study/survey of home owners was done recently (I read about this in a trade publication, but forget the reference) as to the name brand of their furnace/ac/heat pump equipment. about 70% said "I don't know", 20% said "Honeywell" (the most prevalent brand of thermostat).
>>20% said "Honeywell""And my furnace is round"I have found that probably 90% of all people don't know which way the air moves through the system (and most filters are installed backwards.)
Youth and Enthusiasm Are No Match
For Age and Treachery
In another forum (Bob Via) I see that many people change out the thermostat for any problem from blown out pilot, to iced up evaporator coils to burned out fan relay.
I design HVAC systems for a living. I have thought a great deal about this over the past decade or so. If I were building a new home for my family I would want the following:
A geoexchange, water-to-water heat pump with the best COP available, variable speed on the air handler; hydronic infloor radiant heat and a small condensing boiler for domestic hot water (via an indirect water heater) and backup/supplemental heat, a Honeywell MERV 13 media air filter, and simple zoning controls for the air and hydronics (upstairs, downstairs, east & west).
Additional features I would want are a sidestream whole house dehumidifier, an electric/steamforced air humidifier, an integrated programmable digital thermostat with outdoor air temperature sensor and humidity controls and filter status, and energy recovery unit serving as my bathroom exhaust fan and fresh air supply.
So you would spring for the expense of all the infloor and underfloor tubing for heat, AND the supply and return air ducts for the geothermal A/C?
We enjoyed a top end installation of open-loop geothermal water-to-water HVAC in a house we built for ourselves in NE Indiana. Super setup, and very efficient.
I'll explain my choices in more detail, as someone has asked me to do so, but in answer to your question - Yes, I would. The reason being is that the infloor radiant heat is the most comfortable means of heating. A good forced air system is very comfortable and energy efficient and serves to utilize the ducts and air mover for both heating and AC. If my budget were limited, I would choose only the forced air system. Depending on the climate, I would design it to be better at whichever I needed the most, heating or cooling. The reason I would chose both system if budget allowed is to get the best of both worlds.
Wow, that was quite a list! Personally I've not heard about at least half the things you mentioned. Could you go through your list, item by item, and detail why you like each technology? I'm big on making my home as comfy as possible.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Certainly,
geoexchange, water-to-water heat pump with the best COP available,
In regions where the winter outside temperatures allow regular use of a heat pump, this is one the most cost effective ways to heat at night. The geoexchange or ground source or geothermal system removes the cold air from the equation in the winter and the hot air from the equation in the summer. Rejecting heat (air conditioning modes) to 95 degree air is a much less efficienct process than rejecting heat to 50 or 60 or 70 degree air or in this case, water. In the heating mode removing heat from 40 degree water is a much more efficient process than 0 degree air. It is a reality of mechanical heat transfer systems that they operate more efficiently at greater temperature differences, all other things being equal. The GSHP maintans the greatest temperature difference at the most conditions. Even in northern IL, most systems are sized to accomodate cooling as that is the dominating load scenario.
hydronic infloor radiant heat As I posted to Gene, I believe this to be the most comfortable and consistent means of comfort heating for many types of spaces, including a residence. The limitation being that you have no means to move, filter, humidify or dehumidify and for all practical purposes no means to cool either, the air in the space. All of which are necessary for good indoor air quality, amongst some addition requirements, addressd by other equipment listed below. The GHP can provide hot water for hydronic heating, but is limited in the temperature it can supply and this has to be accounted for in the design of the "envelope" and the delivery system.
variable speed on the air handler With either a gas/oil fire forced air furnace/AC or a hydro/DX air handler, these are ideal. The variable speed (as opposed to the very common multi-speed) fan has the ability to run at a very low speed for air turnover/ventilation which is vitually silent and unnoticeable in terms of "draft", ramp up to an addition 3 or four speeds for low heat, high heat , low cool and high cool. I like to circulate a small amount of air 24/7. With a multi-speed air handler, when the fan is ON is runs at either the med/low speed of heating or high to med/high speed for cooling. Too much for simple air turnover in either case. Regardless of the heating or cooling system, maintaining a low level constant air turnover also helps to even out the deadbands present in all thermostats.
a small condensing boiler for domestic hot water (via an indirect water heater(IWH)) and backup/supplemental heat, This is a a means to have a great deal of hot water in a small package (a properly sized 40 gal IWH will produce as much hot water at 100 degF riase as most commercial 100 gal "standard tank" units). Additionally, all but the very best commercial water heaters operate at combustion efficiencies in the 65% to 75% range, where a mod/con boiler, even operating at the high temps required for DHW production is in the high 80's. IF there where an area that needed more heat than the 120 deg HWS the GHP w/w could provide, you have an easy to use source of hot water to supplement, and can use it to temper outside/fresh air for make up to kitchen exhaust and general ventilation.
Honeywell MERV 13 media air filter This, in my opinion, is the best, readily available packaged filter system you can buy for a small application, I would add the differential pressure or Air Watch feature, which coordinates with Honeywell's high end thermostats to monitor the filter life.
simple zoning controls for the air and hydronics Zoning a forced air system correctly is expensive and complicated, too much so for a house. The only real and truly effective means of zoning air systems are commercial grade VAV type of systems. Simple controls, like a Honeywell EnviraZone or TotalZone type of system, add the ability to sense and respond to varying temperature in different parts of the house without the complexity and expense of modulating dampers and variable frequency drives. A well done FA system with good design for the proper ductwork, can mostly alleviate the common problem of upstairs/downstaits conflict, but separate systems are better and more cost effective. Every room does not need to be on a zone. With hydronics, micro-zoning like that is possible and easy to design, install and control to what ever level you deem necessary. I like to zone based on two criteria: occupancy and exposure. The second floor has different exposure than the first. The east from the west. The bedrooms have different occupany than the great room or the kitchen. With some forethought by the architect, some of the zoning can made more simple.
sidestream whole house dehumidifier This feature is more necessary in some climates than others, but it is a very common problem in the "shoulder seasons" and from time to time in the middle of summer, such that the heat gain of the house is simply not great enough to require the AC to run enough to remove moisture from the air. A "side stream" DH unit takes a volume of the return air, dehumidifies it and returns it to the system. It runs based on input from a (de) humidistat and will operate when the AC is on or not.
an electric/steamforced air humidifier This is a tossup between this type and the standard "powered" type. I don't like bypass humidifiers. Powered humidifers work well but can be noisey, electric-steam humidifiers are expensive, not common in residential applications, though AprilAire recently introduced a res. version, and requires a hefty electric power supply and some cast iron drain portions. But they are exrtremely effective, unnoticebly quite and offer far better control than any of the "dripping water" types.
integrated programmable digital thermostat with outdoor air temperature sensor and humidity controls and filter status This is basically a control panel for the HVAC system. IF the entire collection of equipment, controls and components are designed and treated as a comprehensive system, it will, or at least can, function as an integrated system. Maybe some of the Home Automation systems out there would be good/better to integrate all aspects of energy and environment. I have done a lot on the design of my own system, based on a PLC, though not complete at this time.
energy recovery unit serving as my bathroom exhaust fan and fresh air supply This is a means to positively control pressure (with the correct control elements), provide the exhaust which is required and provide the fresh air which is highly recommended. IF you draw a space into a negative pressure, which will occur with exhaust and combustion air use being present without adequate makeup air (I prefer sealed combustion where possible to reduce this effect, but dryers, ovens and stoves are not commonly available that way), you will create uncontrolled inleakage. The environment and lifestyle of the owner plays into this considerably. Almost every humidity and/or mold problem that have investigated over the years was directly attributable, wholly or partially, to negative pressure situations and the subsequent, uncontrolled inleakage. Packaged units with fans and controls to accomodate the ventilation and non-kitchen exhaust needs of a space are readily available and effective. These units do so while retaining a resonable amount of the energy you have spent to condition the air you are now going to dispose of (i.e. exhaust). These can be set up to run on a timer, occupancy sensors or continuosly.
Edited 10/11/2006 2:17 pm by Tim
Thanks! I really appreciate the time and effort you put into explaining all that for me. Really, thank you.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
If you like consumer reports (I do) they have done user surveys about 10 years ago and also about 2 years ago on central HVAC units. results were about the same
winners were Amer std/trane, rheem ruud
carrier in the middle
york, goodman on bottom (worst) - most repairs.
These results are from the owners- not the reviewers- they ask them, did it break in the last 4 years, and do you have a warranty? and then they compile the results. go to a library to get back issues.
never seen any other comparison- the indusrty wants to base your purcahse on advertising, not facts
Edited 10/10/2006 9:15 pm ET by edwardh1
I can vouch for York being on the bottom. I had a York Diamond 80 furnace at the last house. It was very noisy and the igniter had to be replaced 3 times over 9 years. The access panels tabs were difficult to turn and broke.
In my current house, I have American Standard A/C. I'm happy that it's variable speed and very quiet. The condensor is also quiet. When I was going through the A/C selection process earlier this year, I was struck by how many contractors in my area used American Standard. It seems that 60% of them supplied American Standard. The rest were spread across the other brands.
I agree that you're paying for their advertising with some of the larger companies but it seems that you also have to spend some extra money to get better quality.
I too have had very good luck with goodman... i had one bad board that the factory guy trouble shooted for me on the phone.. and had one waiting for me at the supply house when i got there... it was a new install... only other thing i ever replaced was a magnetic contactor $12...
i think somewhere i have every brand made and for the most part all are trouble free... I've never used heat pumps before but i have them for my loft project... with electric strip heat back-up... so we'll see...
for my lofts i went with bryant / coleman they had what i needed in the sizes i needed and gave me a package deal i couldn't refuse... just have to see how they work out... they are good looking units... if that counts for anything
now... i have had some high end commerical units... york i think.. you can tell when you work on em... everything in em is the same size (wrench/socket) the lube points, the adjustment points... all very well made easy to get to... and very high quality....
Like others i think the install is critical... air like water doesn't like sharp turns, the little time it takes to seal every joint with real duct seal material is time & $ well spent just attention to some details will be better than 90% of what usually happens...
p
"Brand" is marketing. Someone is paying for all that advertising.
Installation is far more important than the name on the cabinet.
Energy is not getting cheaper.
Design your home to be the most efficient that you can afford (like 2 x 6 exterior walls and blown in cellulose).
Choose the most efficient HVAC equipment that you can afford- then install it properly.
Granite and stainless steel can always be added later.
Ground source HVAC is very efficient, but it is quite an expensive band aid on a fundamentally inefficient home design.
Hi Gene,
In my area, which sounds similar to your area. "Mid South", my electric provider, CEMC, has a program that they recommend units. I am not at that stage yet. But I am gonna hear'em out. But My understanding is that it is not so much a name as it is an installation.
KD