Any HVAC guys out there?

[Fire-medic]

In doing plans reviews and inspections, I worked daily along the other disciplines, it was a great education. I am sure the other parts of the country have stringent codes, but in FL you cannot install a SEER of 13 now in a new install.

My son just bought a used home of 2300 sq ft & the prior owner (B of A foreclosure) let it go downhill, including infrequent filter changes. The ducts were filthy, and the service co. who did it got all kinds of accumulation out of them.

I have been present for many 'test & balance' inspections with the mechanical inspectors. In commercial renovations, they don't get to plan approval w/o being "on the $" in the system design. I have had differences of opinion with many owners & contractors along the way, and it always comes down to "comply with code." I always liked being present for the smoke evacuation simulations when we light the smoke squibs and watch to see the smoke dampers actuate, the smoke doors close, the fans come on, and the system functions as it was designed to.

If a contractor wants to argue the point of my rejection, I ask him to provide me w/the code section which allows what he proposed in his design, & when I rejected it, I cite the code section on-which I base my rejection. It's all online now, so they can get their comments easily w/o having to be present.

 

[Rusty McNeil]

I run a Ruud system which I installed myself. Been up and running for 9 years now with no problems......cut my bill by a third when iIinstalled it...It's a 134a system, and I keep a full jug of the stuff just in case but knock on wood have never needed it yet.....I'd stay away from units that have any electronic controls in the evaporator or condensor, these things aren't that compicated and there's no need to make them that way, it's just an added point of failure..save the elctronics for the thermostat...

I blew in about ten jillion pounds of cellulose insulation right after too, and added some vents on the exterior attic walls and went with ridge vents after the last hurricane ruined my roof. After all that my monthly kw/hr is about half of what it was when I moved in to the house.

A good system properly installed and with good ductwork should achieve about a 17-21 degree temp drop from the intake to the nearest outlet....21 is ideal but pretty hard to achieve unless your ductwork is VERY tip top.....

+1 on the humidy and oversizing comments, in this area 1 ton per 500 sq. Ft is about right as a rule of thumb, but there is more science to it than that....

The low speed fan for Humidity removal is an ecellent idea. I don't have the two speed thermostat thingie, but simply connected the blower motor for low speed operation and works Ok. I may have to re-visit that after hearing about the thermostat idea.

Condensor and grass clippings = bad

I just flip the breaker off on mine before mowing/trimming around it to avoid this.

Opening up the condensor and hosing out the coils from the inside once a year gets done regardless......

Filter change is a big deal, filthy evaporator is the result of poor filtration, crappy cooling is the result of clogged filter. Both can jack with the system pressures and shorten the life of the unit.......

It is extremely difficult to ever get an evaporator clean once it get's all shitty and gummy with caked on dirt....

Don't forget to make sure it gets a level switch in the secondary drip pan to shut down the unit if the primary drip pan drain clogs up.......

 

[Lew L]

I'm not truly an HVAC guy but as a metal shop teacher in Nevada, I have to teach sheet metal and duct fab. Thusly---- Make sure the ducts and plenums are well sealed. Why loose 10 to 15% of your heated or cooled air to leaks. Seen some pretty poor duct work done by "reputable" companys.
Lew

 

[rebar]

I'm not truly an HVAC guy but as a metal shop teacher in Nevada, I have to teach sheet metal and duct fab. Thusly---- Make sure the ducts and plenums are well sealed. Why loose 10 to 15% of your heated or cooled air to leaks. Seen some pretty poor duct work done by "reputable" companys.
Lew

Depends where you lose it. Conditioned or unconditioned space.

I cant count the times Iv done a change out and found a blanket of dust and crap on the bottom of the A coil and a over charged system. People hot and call for service.. Service guy simply pumps in more refrigerant and ignores the underlying problem.. Then they buy a new system.

I installed a glass window in my plenum after raising my coil so I can see dust or a condensate problem. And a few leaks in my conditioned space dont bother me.

 

[sdt354]

Depends where you lose it. Conditioned or unconditioned space.

I cant count the times Iv done a change out and found a blanket of dust and crap on the bottom of the A coil and a over charged system. People hot and call for service.. Service guy simply pumps in more refrigerant and ignores the underlying problem.. Then they buy a new system.

I installed a glass window in my plenum after raising my coil so I can see dust or a condensate problem. And a few leaks in my conditioned space dont bother me.

Ain't it the truth. Low pressure? Let me put more freon in and get the hell out of here. Oh shit, the low pressure was caused by dirty filters,and evaporator now? Obstruction is the leading cause of low pressure. The compressor rolled a 7? Let me refer you to sales. Service companies need to be watched and questioned by the homeowner.They hate comming to service my system. You can't roll the dice and hope they did a good job.
Steve-o