HVAC central air in particular

[washman]

I think we're all pretty much up to snuff on what laundry appliances we all own, but what about HVAC?

For those of you how have central air, what brand?

Are you happy with it?

Repairs?

Does it carry the freight on hot humid days?

Hi Frig!

 

[gusherb]

Two Trane units.

Yes.

None.

They will hold 72 up to about 100 degrees outside, and keep the RH in the 40s even with the outdoor dew point into the 80s.

 

[ilovewindex]

Does a Mini Split Count?

Daikin

2.5 ton, 1 head unit

No repairs

It keeps the open plan part of the house comfie during ac time, and heats the whole house fine.. Need a second head unit to do the upstairs rooms

 

[whirlcool]

American Standard 3 ton single unit. Installed in 2011. It'll freeze you our even on a 100F day. We keep it at 76F, which is cold enough for us.

The biggest advantage to this unit was how it reduced our electric bill. With our older (1994) Trane XL unit we were averaging about $180-$200 per month during the heat of the summer and the Trane was in constant run mode during the heat of the day. Now with the American Standard we never have a mode that's constant run, it cycles off and on during the day and our electric bills are now $85-$115. during the the hottest months of the year. So the unit is actually paying for itself.

No problems with it so far. The company that installed it keeps calling us to come out and perform "maintenance" on the unit. I know how these a/c guys operate. I do my own coil cleaning and filter changing. I don't have a need for useless "upcharges".

 

[askolover]

Goodman built Amana gas package unit installed in 2000...no repairs.  I clean the coils every year.  Does an ok job but I think they should have upsized it a little more for the age of the house, but that will probably correct itself when the new windows and siding are installed next year along with more insulation in the attic.  Mortgage pay-off end of this year YAAAAAY! 

 

[appnut]

Trane XL18 installed last October. 

It's new

Yes, my old one was an XL18 also.  this one has a new T-stat that monitors Rh.  Right now I have it a 40%.  Keeps the house very pleasant. 

 

[polkanut]

1994 Lennox single scroll compressor unit here.  Just perfect for our 1100 sq. ft. home.  It has performed flawlessly for us since 1998 when we purchased our home. 

 

[washman]

cant recall if I added pic and vid

here it is in operation.

http://https//www.youtube.com/watch?v=DtmZMBIToJA

 

[washer111]

Does Evaporative Count?

Being in Perth, its much less "nuclear" in Summer than up north. Up there, summer days north of 104ºF (thats 40ºC) were commonplace.
The central air, dating to 1984 and rated to about 5 tons, carried the freight ALL DAY, even cycling. Although you'd expect that with a setpoint of about 80ºF (27ºC).

That system had a couple of minor repairs. Before we moved in, TX valve was shot on one side of the heat pump.
Then 1 of the original GE fan motors (Trane unit) packed up, then its companion. Had a small gas leak on the charging value, undoubtedly from the techs servicing the TX valve prior.

In humid weather, it also carried the freight. Despite the shortish cycling (fixed with 3M Filtrete filters... LOL), my indoor thermometer reported a humidity of about 35-40% when outdoors it was 60-85% with temperatures in the mid-80s.

Now, onto here in Perth:
Early 1980's "Bonaire" evaporative cooler system. Works pretty well. Needed a new water pump at the end of summer, as the old one (probably not original, by the looks) packed in. Surprisingly, it seems as though the water pump also controls the mains water inlet, in addition to pumping water onto the filter pads - so no water at all reached the unit when the pump died.

Does it Carry the Freight on "Hot, Humid Days?"
Well, think about it. Evaporative cooling + humidity = BLUEGH. Usually it'll get about 1-2ºC cooler than ambient, and about 20% more humidity, based on my indoor thermometer.
But on a hot, dry day, it works great. I understand many units are very conservative with water, some people have added additional pumps to wet the filter pads even better, and noted the units perform exceptionally well. Even in less than ideal conditions.

 

[sambootoo]

Mine is a 1977 Sears unit made by Heil. Amazingly old but still cranking out the cold. It's a bit undersized for the house and struggles on the hottest days but still going faithfully. Compressor went out in 1986, found a guy that was retiring and had left over parts, replaced that for $300.00. Have replaced the condenser fan motor twice, several capacitors over the last few years and replaced the contactor about 10 years ago (was told that fire ants caused that to fail?.) I know a newer unit would cost less to run but it's hard for me to justify replacing something that's working. I know it's running on borrowed time anyway.

 

[Marky_Mark]

I have Daikin central A/C in my apartment.  It also heats (in reverse/heat pump).  It works really well for both cooling and heating, but the guest bedroom doesn't receive as much airflow as everywhere else and I'm not sure what can be done about that.

 

I have discovered that it seems to consume around 50 W of electricity on standby.  I measured it by looking at the electricity meter with all other circuit breakers off.  Having looked online, this could be due to a crankcase heater to stop oil migration in the compressor.  Has anyone heard of this?  Does your system consume a lot of power on standby?  During the months when no heating/cooling is needed, I'll start turning off the breaker.  But it should apparently be turned back on several hours before use to avoid damage.

[this post was last edited: 6/1/2016-10:51]

 

[vacerator]

1990's Bryant

2.5 or 3 ton R22 charged variable speed fan. Either Copeland or York high efficiency for then, axial piston compressor.
Still runs quiet. Cycles on/off about every seven minutes at 85 degrees f. with my thermostat set on 76 f. When it's above 85 outside, I bump it up to 77. Keeps 1500 sq. ft. comfortable. I have no door to my basement. Cold air drops, so I can't complain at all.
When it's very hot or humid, the variable speed furnace blower fan runs at a moderate speed when extended cooling times are needed. When house temp reaches thermostat setting, the blower ramps up on high just before the outside unit turns off.
I've thought about getting a "nest" thermostat, but my son in law told me if we don't change the temp often, it's probably not worth the $250 investment.
We don't spend that much for cooling in almost two seasons, and my highest winter heating gas bill last year was about $140. So the electronic Honeywell t-stat remains. I don't program it, I always set in on hold temp. Work from home.

 

[cfz2882]

crankcase heater

My Mitsubishi "MrSlim" 12,000 BTU minisplit pulls ~135w standby in cold weather because of the crankcase heater-not sure how cold temps have to be for the heater to come on,but when I am not using the system in winter I turn the breaker off.BTW unit is quite effective for heating in heat pump mode-defrosts of the outdoor unit are kinda fun to watch:when defrost completed,puffs a big cloud of steam when fan restarts

 

[washer111]

@marky_mark

The unit on our old house from 1984 had one of them, given that it is a heat pump, although you'd be mad to use the heat in that part of Australia!

When the unit was serviced, it showed signs of having gone "pop" at some point, and was disconnected. With summer temperatures the way there were, I doubt it was necessary. A crankcase heater is only necessary in sub-10ºC (50ºF) temperatures, and I think it stops refrigerant condensing where it shouldn't be, if my HVAC knowledge serves me correct...

So yes, probably necessary if you need to use the heat, but otherwise, leave the system switched off if you find it using too much power. Its ridiculous to think modern systems aren't using compressor blankets or other means of "pre-heating," rather than leaving electric elements running 24/7 in the current "energy crisis."

 

[DADoES]

 
12 years old, 5 ton, single speed, 12 SEER Carrier heat pump.

Carries the load very well for both cooling and heating.

Repairs:
blower circuit board
capacitor for condensor fan and/or compressor (outrageous $300)
blower motor (outrageous $600)

The compressor is noisy as hell, been so for years.  I think a support spring broke inside the can.

 

[Marky_Mark]

@washer111

 

Thank you for that.  I have edited my post to say that it uses about 50 W in standby rather than 200 W.  I was incorrect.  My meter gives 4000 flashes per kWh.  So you can see the mistake.  I've just played about with the meter's other info that it can display.  But still, yes, it's using something when on standby.  Interestingly, all the other info I've found online relating to this seem to come from Australia.  And it's interesting that you as an Australian have responded to my post.

 

Also, when you say "given that it is a heat pump" do you mean that a system that can only cool wouldn't do this?  But systems that can function both ways (or only heat) do have this heater?

 

[washabear]

I had a 10 SEER Ruud unit, which was in the house when I bought it (now 16 years old). It was OK but had some leaking issues over the past few years. I just replaced it with a 14 SEER Rheem unit. Too early to tell how it will hold up or whether I will even be in this house to find out. Triple-digit days predicted for this summer, so we will see how it performs.

 

[washer111]

@marky_mark

Its rather amusing all the information you've found thus far is from Australian sources. I'd have thought it would be focused on the USA where heat pumps are probably more common.

As simple "straight-cool" air-conditioners are not expected to be used at temperatures 10ºC or cooler, they should not have the heater. Maybe a compressor blanket, but certainly not a heater as-standard.
For special applications, like shops where A/C is required, crank-case heaters are an "optional-extra," or, it was for the dinosaur that cooled our house.

So to directly answer your question: No, I would not expect a cooling-only system to use a heater. The operating environment would not be conducive to the kind of issues it's usually installed to prevent.

 

[intuitive]

Heat pump.. Panasonis splits

We are sitting here with 2x Panasonic inverter split systems running on heat at 21c our place is warm ... not stuffy ... its about 11c outside
1hp in bedroom and 2.5hp in living room. We use a lot and dont notice much change in power bill. We sit at $350/ 3 months power. Gas hot water and cooktop, electric oven.

http://https//youtu.be/A5A1XLgeTSA

 

[cornutt]

We built our house 12 years ago and specified three heat pump units, with strip heat secondary (no gas service in our neighborhood) for three zones. The builder put in Frigidaire units, two 2.5 ton and one 3.5 ton. The larger unit was problematic from the start; the installer didn't get the line pumped down properly, and I had to call a veteran HVAC guy that I knew to evac and recharge it. It has also needed a defrost board and coil temp sensor, and I had to replace the outdoor fan motor and run capacitor on all three units. Three years ago the larger unit started leaking and the indoor coil was too corroded to be repaired, so the entire thing got replaced with a two-speed Carrier Infinity system. So far that system has been perfect, and we have seen a bit of improvement in our utility bills.

Cooling is no problem since the units, being heat pumps, are oversized for cooling. The house has an HAI/Leviton home automation system, so that controls all three units.

 

[artcurus]

about 2007 Carrier with Puron.
Lately it's been running really humid inside the house, but I replaced the filter and it seems to be doing better. I do need to clean the evap coil. It will cool the house down and works well during hot, humid days. The eco friendly refrigerant doesn't have the same air feel at all as my bedroom 2003 Friedrich room a/c with R22. I love that Friedrich.

 

[gusherb]

It seems there is a stigma associated with R410A vs R22 and R410 not running as cold as R22 or performing as well overall. The real difference is actually the design of the system and not the refrigerant. Higher SEER systems rely more on larger coils for their capacity and efficiency and operate on smaller compressors. What this means with larger coils is a much lower delta T (warmer indoor coil and cooler outdoor coil) which effects the latent capacity of the system therefore resulting in less dehumidification than before. With the higher efficiency systems this also means that they need to be kept clean and made sure they're getting proper airflow more so than old systems because capacity will drop off faster due to the use of smaller compressors. Older systems had a higher tolerance for this because the compressor was much larger.

In real world use a 13 or 14 SEER system will perform about the same as a 10 SEER system In terms of latent cooling. It's when you get above 15 SEER that what I explained starts coming into the equation. We have two 13 SEER R410A systems at home that replaced two 1990 model R22 9 SEER systems, in real world use the new systems function exactly the same as the old ones but much cheaper to run. I still get about 52 degree air out of the vents which is a 20 degree delta T, just like the old systems. The evaporators are matched exactly to the condensing units (keep an eye on that, some system configurations require oversized evaporators to meet efficiency requirements to get utility rebates). An An oversized evaporator will result in reduced latent cooling.

As for window units, I've yet to see any R410 model that doesn't perform the same or better then it's R22 counterpart. I had a 12,000 BTU R410 GE (rebadged Electrolux) that blew 29 degree air, or a few different LG's that blew in the lower 40s. I don't think you can get much colder than that without a freeze up.

I noticed something new at the Homo Depot the other day speaking of window units, the LG they were selling said it had R32 refrigerant in it...

 

[gusherb]

[No message]

 

[washman]

I follow ya GusHerb

to a point. Including my digs with a matched Goodman furnace, air handler, coil, and outdoor unit along with 2 co-workers who also have 410a systems, I can say for sure the 25 year old Heil unit at the condo cooled much quicker than the 410 units.

Having said that, it is hard to go totally apples to apples, because my ductwork in my new digs is entirely in the attic. And it sho gets hot up there. In the condo, the ductwork was in the floor as are 2 co-workers digs.

Once the Goodman has run for a few, the air is indeed nice and cold and I don't see excessive cycle on times to bring down the temp from say 79 to 76 (when I get home) or to maintain a constant 76.

One year and 16 mortgage payments in, I am satisfied with the Goodman setup. Let me get back to you in 5,10,15 years with a more accurate assessment of the reliability of the thing. Recall that in the 15 years I lived at the condo, neither the furnace nor the AC needed any kind of repair. And yes, I used them both to whatever extent was necessary to stay comfortable.

 

[gusherb]

You see, the refrigerant has no effect on how quickly the system cools, starts to cool, etc. it's all in the design of the system, whether it has a piston or TXV etc etc.
Both our systems have TXV's, the attic system pretty much within 10 seconds of it starting from hot you can feel the outlet air cooling down, it starts to cool quite quickly. The downstairs system takes longer to start blowing cold, despite being a TXV system as well, could be because that condenser has a Climatuff scroll compressor in it while the upstairs unit has a rebadged Copeland scroll, could be the way the TXV functions. I'm not sure exactly.

The 25 year old Heil probably was oversized and of course ductwork in conditioned space makes a pretty significant difference in efficiency.

I think I forgot to mention, the system at work has a 13 year old 3 ton 10 SEER Heil with a matched 3 ton Heil coil on a piston. I don't notice any real difference in performance from it to the 13 SEER systems at home. One characteristic of a fixed metering system is that they cool better the hotter it gets/higher the head pressure gets, that is the only difference I notice between that system and the ones at home is that it tends to blow colder when it's real hot out.

 

[washman]

Piston on mine

not sure if the condo was TXV or nor. Being that it was rental, I would go with piston.

I did verify mine is right sized for the evap coil and condenser. Once it gets percolating, it puts out cool enough air. Like I said, it does not run excessively long or frequently to keep 76 on an 85 degree day or above.

 

[gusherb]

That might be why yours takes longer to start cooling, since with a piston the high side has to build pressure before it starts to cool. I think most TXV's hold the high side pressure when it's off so as soon as it kicks on it just starts cooling.

 

[circlew]

Gibson

I was surprised to see this brand on a central air unit that was recently installed at a home a few blocks from me.

I looked it up, and found it is a Nortek brand. They license the Electrolux owned brands, which also include Frigidaire, Kelvinator, Tappan, Philco & Westinghouse.

They also have the rights to the Maytag name for HVAC.

Nortek is the parent company of Broan-NuTone, in addition to several other brands.

 

[washman]

Nortek used to be Nordyne

a major supplier of HVAC to the mobile home industry. Miller and Intertherm are two known brands.

Nortek is fond of microchannel "technology" (read: cheap) and has 2 facilities in Mexico in addition to a non union facility in Dyersburg, TN.

FWIW after going back almost 40 years of headaches with the Intertherm furnace in our 1974 mobile home, plus what I have read on so-called microchannel "technology" I would not purchase any of these units. Add to that an increasing number of units are coming out of Mexico pretty much seals the deal for me should I need to replace the non-union Goodman outdoor unit.

(pretty asinine how they are slapping the word "technology" on a condenser design that has its roots in the 1970's on automobiles)

 

[gusherb]

I think Nordyne is pretty universally hated in the HVAC industry. Apparently their support is horrible.