Plz Help Insulation questions

Re: Plz Help Insulation questions

techntrek wrote: »

26 SEER:

http://catalog.mitsubishipro.com/item/mr-slim-m-series-heat-pumps/msz-wall-mounted-inverter-heat-pumps/item-1386?

http://www.e-comfortusa.com/products/9rls-halcyon-wall-mounted-mini-split-single-zone-heat-pump-26-seer--9000btu/1345

One is Mitsubishi, one is Fujitsu.

The quote which you used when you first said 26 SEER was 'Coot talking about Sanyo. You did not specify that you were talking about some other unit. Your post made it sound like the *Sanyo* has a 26 SEER rating.

Which they certainly do not.


*I* mentioned Fujitsu because they DO have ratings that high - unlike the Sanyos which were under discussion at the time. So yes, there are mini-split systems that can be had with such ratings - but NOT the Sanyo.

Re: Plz Help Insulation questions

Nomore wrote: »

I keep my thermostat at 77 at night and 78 day, it does run all day I talked to a friend that works for an AC company and he told me to put in a 5 ton. I had a couple companies recommend same. I think I am going to have to do that As I mentioned on the initial post, we did a reverse pressure test "I think that is what is called" and there are no leaks on my duct..com/[/url] But have not monitored in a while, maybe I need to double check things.

A/C companies want to sell you a more expense system.

Sorry but 5 ton for 2000 sq ft is way overkill. My target run time is maximum 50% duty cycle. Too small a unit and it runs all the time without enough cooling. Too large, it runs too short and you do build up humidity level between runs. You also want to have some reserve capacity for large gathering holiday dinners and such. It is good to have a ceiling fan slowly circulating air in the room where thermostat is located.

Your A/C electric bill is way out of line for 2000 sq ft and 78 temp setting. (unless you are keeping your windows open).

If your thermostat does not keep track of run time get one that does.

When I was a younger I worked for a TV repair shop that also had A/C repair shop next door. One of the guys bragged that he could overcharge the Freon level in a central A/C so the compressor would fail in about 14-15 months, just outside the warranty period.

One time when I came home from school to my parents house I noticed that when the A/C came on there was a louder then I previously remembered startup buzz in the breaker box just outside my bedroom. The wires seemed to be jumping in the conduit. When I asked my father about it he said that two week prior he had a preventative maintanance service call on the unit and the guy added some Freon (which he charged an additional $100 for). I told him to call another outfit to check it out. It was overcharged with freon.

Overcharging refridgerant will cause the compressor to consume more power, overstress the compressor, and reduce efficiency. One way to detect it is checking peak startup current but you have to know what is normal for that model unit. Setting correct refrigerant level is a complex process if it not done based on volume for line runs at installation time. You cannot tell just by putting pressure gauges on outside unit lines. Many new installs come with precharged compressors. Installer just adds a small additional amount of refrigerant based on copper line run diameter and length from compressor based on tables supplied by manufacturer. After install it requires measurement of air temp through outside condenser, air temp in and out of evaporator as well as input side air humidity. Higher outside temp will drive up high side pressure. High humidity on input air to evaporator will drive up low side pressure since it requires much more heat energy to be exchanged to convert water vapor to water. Too much lubricant oil in the system also reduces efficiency. Not properly evacuating system before releasing precharged refrigerant also screws efficiency.

Another common practice by installer companies is to mix outside unit tonage rating with different air handler tonage rating. Besides effecting efficiency you can also throw out the factory supplied refrigerant charge tables making it more likely to get an improper refrigerent charge level.

Common failure mode on central A/C's is dust clogging evaporator coil. It is like not defrosting a refrigerator. Evenually the evaporator coil may freeze up with ice due to lack of air circulation which causes even less air circulation. I clean out my evaporator with evaporator cleaner and spray water through evaporator, collecting it on other side with wet/dry vac. I do this every two years. When I had my air conditioner replaced I had the guy add about 3' more line with a loop so I can slide out the evaporator from air handler to make it easy to clean.

I am not saying any of this is your problem but your A/C power consumption is out of line with what you are saying about your house.

Re: Plz Help Insulation questions

In Florida its cheaper and better to have a contractor do the blown in Fiber Glass. It actually costs less than the DIY Home Depot which only offers cellulose for the blown in

Save yourself time, money and call your local contractors for a quote. Remeber , R40 minimum!! that's 14", and its worth the $$$ to do extra and bury the duct work.

On my home it was ~200 more to bury everything

Re: Plz Help Insulation questions

Consider Radiant Barrier, it helped my home in Lake Worth.

Re: Plz Help Insulation questions

Nomore wrote: »

Wao, you guys are awesome, I took your advice and called some contractors and my first quote came in at 2200 to Blow R-38 @ 16” of Formaldehyde-Free white Blow Johns Manville insulation to ac attic spaces only.

I did not find reviews online on the company, but they sounded ok over the phone. Is that type of insulation fine?

That's not bad, not great price and yes you want the white fiberglass ... I had R40, which was a top off of what was about R20 already installed plus a 2 car garage which had no insulation on it for 900 two years ago

Figure your double that. Its a negotiation process, get at least two other quotes, you want R40 and the ducts buried, HD price is a ripoff

Re: Plz Help Insulation questions

Watch out for those Low-E double & triple-pane windows. If they begin to distort in the center, the sun's energy(low in the sky) can be reflected and magnified onto nearby structures at very hot temperatures. I've seen one TV newscast that showed incredible warpage to a neighbor's vinyl siding. That neighbor was next door to a home with deformed low-e windows.

Re: Plz Help Insulation questions

Nomore wrote: »

Yikes, I hope it does not happen to me, I have one of those cheaply made but expensive plastic fences.

The sad part is, that the industry already knows about the potential harm that may come from distorted low-e windows . Most companies that sell them include either a disclaimer against responsibility to nearby structures, or ensure the warranty expires before the windows distort. Either way, might want to check the fine print of your product warranty.

I am trying to find the newscast where they showed the damage, it was on youtube, but at this moment I'm unable to locate it. A small percentage of low-e windows develop a center distortion, creating a magnifying glass for low-angled sun. It put incredible heat on the house next door.

Here is a link to a PDF from vinylsiding.org that describes the condition in detail.

http://www.vinylsiding.org/aboutsiding/cleanmain/solarandheat/NAHB_Reflected_Sunlight_from_Low-e_argon_clarified_doc.pdf