Most important install items to look for?

[jimpy]

OK:

I have been reading for several months, learning a lot from the professionals on this board. Everyone agrees that most problems come from poor installation. I am going to install a dual fuel system with 13-14 SEER HP with probably 90%+ gas (2-stage, VS) furnace back up.

So, my question is this: What are the key considerations an informed homeowner should pay attention to when the installation is underway? Should I insist on all metal pipes, or is some flex OK? Is mastic tape OK or should I insist on something else? What about the connections at the unit? If any of you guys would like to give me your top five or top ten things you see done WRONG, then I'll know what to watch for during install. I've remodeled houses for 15 years and had several heating systems installed over this time. I worked for an HVAC company in college, but just for one summer. I'm by no means an expert, but know more than the typical homeowner. Again, thanks for all the great information and responses to previous posts. One other question: In a relatively mild winter area like East Tennessee, would I be better off putting more money in a higher SEER HP (say 15,16 or so rather than 13,14)and saving a little money by going to an 80% two-stage VS gas furnace rather than spending more money on a 90+ gas furnace and lower SEER HP?

Responses would be greatly appreciated.

Jim Pryor

[Steve Wiggins]

Is this application an attic mount or where condensate drain leakage can cause damage? If so I have another whole list of gotcha stuff....

Forget about stressing on SEER & HSPF rating..it means virtually nothing, just a sales gimmick. If you want efficiency 1)tighten up house (usually ceiling penetrations) and 2) keep equipment clean thru proper air filtering.

I am big on service access. Can the dang thing be worked on when the installers are long gone? Is it easy access to the air filter and is the filter a common size so the HO can maintain it without a major pain?

I am also big in SEALING all cracks, ducts, joints, door panels...etc. What good is a nice air filter if the dirt just bypasses it? Foil tape & mastic are ok on the ducts but clear silicone applied to joints in equipment/plenums makes a cleaner looking job.

Are you getting a refrigerant control that modulates with the heat load of the house or one of those cheap fixed orfice thingys? If you are getting the luxury of a TXV are you getting one on the outdoor unit as well?

How about a start kit? Every compressor needs one to take the stress off the run winding during start up.

A resistance heater on the outdoor compressor is VERY important, esp. in Tennessee....brrrr. Manufs leave this off and don't tell the HO because it REDUCES COST and INCREASES EFFICIENCY RATING. What they don't tell you is it also reduces equipment life....bummer. See how the SEER is deceptive?

You will have a big and small refrigerant line. Since this is a heat pump shouldn't BOTH lines be insulated? Yeah I think so.

I hope the eve of your roof doesn't drip water on the outdoor unit What if the temp is just right for the attic heat to melt ice/snow and dribble water on the outdoor unit where it freezes (out of reach of defrost) and locks up the fan blade? Dad gum bad fan motor every summer and can't figure out why...hmmm.

Any labor warranty? Or just parts warranty?

[Edited by Steve Wiggins on 10-21-2005 at 11:56 AM]

[jimpy]

Thanks Steve:

You've spurred a few more questions.
What's a start kit?
Does a TXV normally come on the inside unit but not the outside unit and if not, why not, and how much should I expect to have another installed? What does it do for me?

What is the resistance heater on the outside unit for?

What is the purpose of the refrigerant control that modulates with the heat load? What makes it better than the other thingy?

Nice idea about the ice/snow on roof, but not much worry about that here since we rarely get much snow these days. Global warming and all. Also, I'm glad this unit is in the basement not the attic.

Thanks again.

[Steve Wiggins]

The TXV refrigerant control keeps an even temp inside the refrigerant line to help keep the compressor cool. It also lets the coil hit dew point sooner for better humidity control.

A start kit is an extra starting boost for your compressor to extend its life.

Heater on compressor is to keep liquid refrigerant out of the refrigerant oil. Diluted oil reduces lubrication and causes premature compressor failure.

I think there is a magnifying glass on things like duct mastic when there should be closer attention to "design detail". Step back and look at the big picture instead of focusing on every little small detail is my philosophy.

Link to duct sealing article in ACHRNews magazine: http://www.achrnews.com/CDA/ArticleI...nalNews_Item/1,6084,128736-South,00.html

[Edited by Steve Wiggins on 10-21-2005 at 05:09 PM]

[dash]

First things like SEEr do count alot,now it's true if it's not designed ,installed and serviced properly,you won't get the SEER or the savings in operating costs.

You want a Manual J,S,and D from ACCA,to size the equip. ,select it,and design the duct system.Then you it installed properly.

No leaky ducts or refrigeration lines,etc.,etc.

We see more the are not sized properly ,than por duct or leaks.

A TXV,variable speed indoor fan and a great control system,will provide more indoor comfort,take a lok at better than standard filters as well.

[souper phly]

Originally posted by Steve Wiggins
You will have a big and small refrigerant line. Since this is a heat pump shouldn't BOTH lines be insulated? Yeah I think so.

I've heard that several times but why would you need to insulate the liquid line? Even in heat mode it's still the liquid line.

[Steve Wiggins]

Insulate it to prevent energy escape and because it really doesn't add a great deal of cost to the job. Besides you can make it a selling point of you something you do extra that your competition doesn't.

[souper phly]

Ahh heat loss, I was thinking condensation.

[bigtime]

Originally posted by Steve Wiggins
Insulate it to prevent energy escape and because it really doesn't add a great deal of cost to the job. Besides you can make it a selling point of you something you do extra that your competition doesn't.

Since it doesnt cost much its good to insulate the thermostat wire also. (heat pump only)

[amickracing]

Ok, I'm confused.. insulate the wires?

[wayner211]

I would say he's being a wise guy

[Steve Wiggins]

I don't know where you are buying your wire but mine comes already insulated. It is a great selling point to spec the stat wire ran inside conduit esp. @ the outdoor unit.