Plenty of new units available with R410a, if you are worried about R22 phase out.
Anyone have links or article references for some good analysis of R22 replacements? I would like to be able to spec out a new system that won't have its refrigerant phased out.
I have a copy of an older ASHRAE review of possible replacements. That info however, is rather dated.
thanks in advance...
Plenty of new units available with R410a, if you are worried about R22 phase out.
The only publicly available information on options to replace R-22 will be prior to the individual companies deciding on their long term strategy (pre 1995). At that point, new information becomes a potential competitive advantage and will never be published. All you will see from that point onwards is the marketing messages designed to promote their choice and gain competitive advantage.Originally posted by theslumlord
Anyone have links or article references for some good analysis of R22 replacements? I would like to be able to spec out a new system that won't have its refrigerant phased out.
I have a copy of an older ASHRAE review of possible replacements. That info however, is rather dated.
thanks in advance...
If you want a good picture of what the R-22 replacements will be, look at Europe today. R-22 can't be sold in new equipment, so the R-22 replacements are a reality for them now. All the major US based companies are doing business in Europe providing systems without R-22. I doubt you will find an unbiased review comparing all the different manufacturers R-22 replacement offerings - it looks like you will have to do the work yourself. The links above have inherent biases built into them because they have a dog in the fight.
Don't expect to get something like you requested for free ....
Remember, the price of replacing A/C units will dramatically rise next year as you will be stuck with 13 SEER. Many areas of the country cannot justify high SEER units economically and you slumlords don't usually use high buck units in rentals you don't pay the bills in. Going with a 10 SEER system this year might be your best bet. There are dropin 22 gases out there (www.icorinternational.com) that can be used later if R22 gets pricey. I was in Icor's facility last summer on the hottest day we had. Their older units all had NU22 in them. Very comfy!
Landlords also tend to not want to change indoor coils. Next year with 13 SEER outdoor units we could get to the point where you won't be able to get them to work properly on a low SEER evap.
12 SEER is almost standard in Florida due to the energy code.When that happened,12SEER pricing dropped ,a lot.
We expect the same will happen when the National minimum is 13SEER.Yes it will cost more then 10SEER today,but less than 13SEER today.
I put a 10 SEER in my unit. SEER is a terrible method to calculate A/C efficiency. ASHRAE did a good test study (published July 2002) comparing 18 SEER units with a 10 SEER. Results:Originally posted by BaldLoonie
Remember, the price of replacing A/C units will dramatically rise next year as you will be stuck with 13 SEER. Many areas of the country cannot justify high SEER units economically and you slumlords don't usually use high buck units in rentals you don't pay the bills in.
High SEER units removed 25%+ less moisture (by mass).
When the temp difference increased (very hot days outside) the high SEER units performance degraded at a faster rate than the 10 SEER units.
Energy savings were minor and thats without considering the effect of higher indoor humidity (you have to set the thermostat lower to feel comfortable).
ASHRAE pushed for a better standard to determine efficiency. The Feds so far have refused.
Thats because efficiency and comfort are not one in the same. ARI is the industry's efficiency rating department and will not allow units to be marketed with EER, or HSPF or any other means of efficiency primarily. (Residential).
Look at all the variables when selecting equipment. SEER, EER, HSPF (heat pumps). Sensible Ratios on higher efficiency equipment is not worse except in the price fighter units where an oversized coil achieved the SEER at the cost of the comfort and overall system efficiency.
Those units will continue to sell to unsuspecting or price driven consumers (such as landlords) and sold by those who choose to play in that market or who cannot sell comfort but are also hung on price. ASHRAE's article was geared toward the loopholes in the current SEER rating. Some mfg's are also concered about overall comfort and performance.
As an example of my point and to disprove some of the garbage you might have heard...
10 SEER, R-22, 3 ton ac system on builder grade gas furnace (Brand unnamed).
SEER 10
EER 9.5
Total Capacity 35,400
Sensible Capacity 25,200
Ratio 0.712
Sound 78dB
16 SEER, R410A, 3 ton ac system on VS high efficiency gas furnace (Same Brand)
SEER 16.75
EER 13.08
Total Capacity 37,400
Sensible Capacity 28,000
Ratio 0.748
Sound 72dB
2 stage with additional Dehumidify mode avaialable.
The second unit far out performs the first unit in all catagories including latent capacity which shoots your myth apart.
[Edited by docholiday on 04-07-2005 at 03:17 PM]
You mentioned 18 SEER. so I'll add that... Same Setup.
R410A refrigerant also.
SEER 17.45
EER 13.06
Total Capacity 37,400
Sensible Capacity 27,600
Ratio .738
Sound 72dB
2 Stage also with dehumidify modes avaialable.
..I grant you that looking at other performance factors than SEER is better way to do it.Originally posted by docholiday
T
The second unit far out performs the first unit in all catagories
[Edited by docholiday on 04-07-2005 at 03:17 PM]
Question though in regards to those performance ratings.. What about other points outside the range of the ARI Dry / Wet bulb temperature test points?
I wish the govt. would require a performance range be taken, to give a designer a better idea how the unit will perform in a particular situation.
I did about five years of work auditing commerical chillers (for a utility, part of an energy savings program). It was amazing how far off some of these systems were from their 'design performance' when actually installed in the real world.
Your right there is no lower level standard, However design conditions must be achieved. 2 Stage units and units with dehumidify capabilites overcome many of those objections.
If you are talking 70 degree room temperatures, you need to understand that AC systems were never intended to use this as a standard. Thats not air conditioning, nor is it comfortable IMHO, especially if the humidity is in check. Yeah I know, "Thats where I want it" well... too freakin bad. Its on the boarder of being enough load to keep the unit from failing and freezing while maintining some ability to control the latent load of the hottest days. No MFG is going to rate their equipment this way.
70 degrees at 50% relative humidity is a miserable 57 degrees wet bulb. 76 degrees at 45% is around 62.
ASHRAE even does most of its figuring for thier arguments on a 78db 40% return air temperature (room conditions). which also is about 62 wet bulb. ARI uses 78/67 which is intended to be used as a fair NATIONAL condition. Many of the arguments are based on "Where I live". SEER should be modified as expectations of AC has changed. What to? I dont know, but I would say 88 ambient and 75DB/62WB would be a fair comprimise as long as EER is also published.
btw, a designer should be looking at both SEER and EER along with Sensible ratios so he can make a wise decision and develop some sort of curve for his region.
70 isn't a good indoor temp, too warm for me I set the King at 68 in the summer
ARI indoor conditions are 80 db and 67 wb, not a condition many people would enjoy either.
Also, indoor airflow plays a huge factor in latent capacity. Very rare for us to find a system with the cooling speed something besides high even though a good many units have excess blower capacity based on the A/C size.
Doc, what was skinny on 3 ton 10 SEER units about 10 years ago? The AKA36 was rated at 33,000 total, the 37 was 35,000 total, the increase was all latent. Only diff was which model scroll was installed?
[Edited by BaldLoonie on 04-07-2005 at 04:46 PM]
10 years ago? I dunno.
I guess the real problem with rating them at lower numbers like you suggested is when you get much below 80/67 you tend to cycle the unit more and there are too many variables to that since a the differences of equipment sensible outputs vary. Even at 80/67 your going to cycle.
Not to point fingers but at least one mfg requires a field installed time delay to achieve their SEER rating... Somehow this is accepted as a legitimate means.
Really though, if you feel the need to cool to 70 degrees, you will and should expect pay alot more to cool your home. Remember the relative humidity at 70 is higher than it is at 76 when grains of moisture are considered.
I used to work on temperature and humidity controlled boxes. One of them went from 100*C (212F) to -50*c (-58*F) in just over 2 hours. The Box was 20'x20'x10'(yes those are feet). The room was steel and it housed car bodies and other massive metal things. Imagine the HP to accomplish this. Anyway, the problem was passing through the sensible temperature that fast and dealing with the moisture. (It was humidity controlled at 40*C/70%rh (104*F/70%rh) before climbing to 100*c.)) The amount of latent work required was incredible and a real issue once you passed through the 5*C mark. It would just about rain, then snow in the room and the sensible change in temperature was difficult once the coil iced. at 40*C75RH, you are talking 252 grains of moisture per pound. At that same grains we simple changed the senible up to 100C and that made for a relative humidity of only around 5%. At 0*C and 100% humidity you only have 26.51 grains. Now take the volume of space and figure out how much water came rolling out of that system in the time period coming down from 100-0*c.