How to know which HVAC guy is right

[RandellP]

Hi all, and thanks in advance for any insight you offer.

I live in portland, Oregon. The house is currently 2550 sq feet. Has one unit to do the whole house.
Trouble is, the upstairs is always significantly hotter than the downstairs.
We will call this problem 1.
Problem 2 is that I would like to do an addition of about 500 sq ffet, mainly upstairs. But at the end of the house furthest from the unit, and I would like it heated and cooled.

I have talked to at least three hvac guys (each from a different contractor bidding the job). And they don't know what each other has suggested.

current setup... only one return, in the stairwell that goes upstairs at about the floor level for upstairs. Only one down stairs room is vaulted, and that vault doesn't open to the upstairs (there is actually a wall with windows from an upstairs room looking into the vaulted downstairs room) Temperature differential from the thermostat (downstairs) and the master bed room upstairs in the summer is about 5 degrees.

Guy 1 says he can just add vents to the existing system for the new rooms, and make the system a two zone system if I want to make it so they balance better.

Guy 2 says he can do the same as guy 1, but we need to add a return upstairs to get the balance we are looking for with the 2 zone system.

Guy 3 says he would have to add a unit in the attic to handle the addition, and unless we want to mess with the existing upstairs rooms so that the attic unit can manage them as well, we will need to add a return for the existing system upstairs and two zone that existing system.

needless to say it gets more expensive from guy 1 to guy 3.
But the apparent experience level of the guy increases as you go from 1 to 3.
And the amount of time they actually looked at what was there increased from guy 1 to 3. As well as time spent brainstorming about a solution.

So normally I would think guy 3 was trying to sell me more than I need. But the time and experience factors seem to imply that the other guys were just trying to get their contractor the job, and might not be concerned about the end product.

Any tips on how I can figure out what is really needed here?

Thanks...

Randell

[beenthere]

I'd say guy 3 addressed your existing structures issues and your addition the best.

[ADillon]

Air conditioning is just that air...conditioning. You must return air to the unit, condition it, and return it to the space. Pumping cold air into a space will not cool or dehumidify it. A the very least, it sounds like a return needs to be added upstairs with any additional run that might go in. With out more load calc data the rest is hard to say. But the second unit upstairs for the addition and to supplement the second floor would deff get you want you want which is comfortable upstairs. It may leave the downstairs unit oversized which could give you issues. zoning might be the way to go. A different way might be to do a mini split (ductless unit) for the addition. just some thoughts much more info is needed...

[RandellP]

Well I don't think I really expect a direct answer. I am hoping for ideas on how to figure out the answer...

I am confident the 3rd guys solution would do the job, but the cost of it is at least $ more than the other solutions. And probably more like $ really. Which is like 150% more or so. This makes me think there should be some middle ground. And he seems dead set on the second unit. Hasn't even proposed a way to use the single unit even though he admits it has the capacity.
Also he seems hung up on what I think are simple things. Like the current supply for upstairs runs on the East side of the house, and sends ducts with the joists to the west side. The upper floor hangs out over the front port on the East side, and the supply is run above the porch. When talking about increasing the size of that supply, I suggested taking the ceiling of the porch down to access it. He said that wouldn't work, that we would have to open the walls from the inside of the house into that same space. But I can't see how that would be any different...
He also seemed to think that vents on the west side can't be moved one or two joists over... I think he means, can't be done without heading off a joist or two. But he doesn't say it that way. So it is hard to tell when he means "can't" versus he doesn't know if it can be, or he doesn't want to...

Randell

[beenthere]

Ask each guy why the other guys ideas/way isn't better. They saw your house, not us.

Thats gonna be your best way to figure it out.

[RandellP]

Ask each guy why the other guys ideas/way isn't better. They saw your house, not us.

Thats gonna be your best way to figure it out.

Tried that... I got the "I don't know what ... was thinking but what I am saying is this". Which really is the smart answer, you ain't lieing when you say you don't know what someone else was thinking...

Randell

[beenthere]

Then get some more estimates. And see if any choose the same route as the first 3.

[BaldLoonie]

Look for H-T member SkyHeating. He's a Portlander or whatever you guys call yourselves Have him out and see what he thinks, from reading his posts on here, sounds like a sharp guy.

[RandellP]

Then get some more estimates. And see if any choose the same route as the first 3.

Well, if I call an HVAC guy he will realize that the contractor will use his own guy no matter what this guys says. So he has no reason to even come out.
Can I pay a guy for advice even if there is no job for him? And if so, what is a good amount to pay for advice?

Randell

[beenthere]

We don't talk prices here. A designer would come out. but he won't be cheap.

[RandellP]

We don't talk prices here. A designer would come out. but he won't be cheap.

I have a design for the addition... it's just a question of how to manage the hvac. So far the HVAC guys are free estimates since they are working for the contractor... I bet most HVAC guys don't even have many calls like this. So whoever I call isn't going to have a number either... what should I offer to start the ball moving?

Randell

[beenthere]

By designer, I meant an HVAC designer.

Pricing questions are not allowed.

[RandellP]

By designer, I meant an HVAC designer.

Pricing questions are not allowed.

Is a designer different then the guy who implements the design? Like an architect vs a framer?

[beenthere]

Yes, designers generally don't install.

[AtticAce]

In this present hvac environment it is best to put a little extra money into the building budget to cover the hvac engineering, part of the design would include a write up some specifications that all contractors must use in their install quote. This is rarely how it works in real life and why most homeowners are dissatisfied with their hvac systems.

I would add installing a separate zone would definitely take care of the addition if it gets designed installed correctly and that is a toss up most times.

Option two would be to attach all three proposals to a spinning wheel and throw a dart.

[btuhack]

Randell, Guy 3 has the most complete solution, but you contradict it by stating that his number is 150% of the solutions that don't solve the problem.

Huh? Let's say I find a great deal on 65 octane gas, who cares it won't get me down the road.

I liked how he avoided an overly optimistic position on the concealed conditions of the framing. It could go either way. Your house, your problem, your signature on the change order sir.

Retrofitting zoning on an existing system? Expensive and complicated to do correctly if the opportunity is even feasible. Do it wrong and you will regret it.

[dan sw fl]

Look for H-T member SkyHeating. He's a Portlander or whatever you guys call yourselves Have him out and see what he thinks, from reading his posts on here, sounds like a sharp guy.

Definitely call SkyHeating ... I believe he knows HOW TO LISTEN. Therefore, he will address YOUR Needs in a manner compatible with Science AND Your Budget.

[RandellP]

Definitely call SkyHeating ... I believe he knows HOW TO LISTEN. Therefore, he will address YOUR Needs in a manner compatible with Science AND Your Budget.

So is he a designer? or an installer?

Randell

[tedkidd]

I live in portland, Oregon. The house is currently 2550 sq feet. Has one unit to do the whole house.
Trouble is, the upstairs is always significantly hotter than the downstairs.
We will call this problem 1.
Problem 2 is that I would like to do an addition of about 500 sq ffet, mainly upstairs. But at the end of the house furthest from the unit, and I would like it heated and cooled.

current setup... only one return, in the stairwell that goes upstairs at about the floor level for upstairs.

Temperature differential from the thermostat (downstairs) and the master bed room upstairs in the summer is about 5 degrees.

Randell

Hi Randell.

First, sounds like all three guys are taking wild guesses. Throwing convincing ideas together trying to get compensated for the time they spent at your kitchen table. Is this unethical? I don't think so.

QUESTION: With no guarantee of compensation, and less than 33% chance of a sale, how much time can be expected to put into a complicated design?

ANSWER: As little as it takes to sell the job.

Free advice is worth what you pay for it. (Seems you get it, I'm hammering the point for other homeowners reading this.)

Typical causes of temperature imbalance you complain of are:

1. Oversized equipment
2. Attic leakage
3. Insufficient attic insulation
4. Duct leakage
5. Poor return
6. Undersized supply

Two pieces of equipment is brute force, usually unnecessary, short and long term costly, and IMO inelegant approach to curing problems that are better addressed by fixing the house. 2 pieces of equipment to service and replace, who benefits from that?

So your current house is broken, and you want to add to it. You want to understand what is currently broken and what would fix it so that can be incorporated into the work rather than just picking the option that "sounds" best and living with the ensuing disappointment.

QUESTION: if you call an insulation salesperson about comfort issues, what solution do you expect will be recommended?

QUESTION: if you call an hvac salesperson about comfort issues, what solution do you expect will be recommended?

Are the answers redundant?

Might want to start with an energy audit. Really learn whats going on with your home, from a more comprehensive perspective. Consider this, is the bedroom uncomfortable because it doesnt get enough cooling, or because the cooling is lost too quickly? If improvement to building enclosure can fix or reduce comfort problems the audit should uncover that.

Fix the house first, then design the hvac for the fixed house. Designing hvac for a broken house results in frustrating comfort problems and high energy costs in perpetuity. Fix the house later and you may find yourself with mismatched hvac.

See if they will include duct leakage and score (tells airflow and btu delivery at each register) and room by room load calculation (so you can understand the current shortfall in delivery). Next get calculation of load for new rooms. Then get duct design that will supply the whole thing. Your basement ductwork may need modifying, an opportunity if you'd like equipment relocated.

By paying for this you create accountability for quality design and ultimately a better result. Look for BPI or RESNET certified and accredited firms.

If you want a customer testimonial about these issues contact user "Shortcircuit" in MD. I helped him navigate a major retrofit and he can explain these issues in depth.


Or put a mini split heat pump upstairs and leave the doors open. ;-)

[RandellP]

Definitely call SkyHeating ... I believe he knows HOW TO LISTEN. Therefore, he will address YOUR Needs in a manner compatible with Science AND Your Budget.

I gave him a call, but he only does designs if he can do the install. And contractors like to use their own hvac guys... So I guess I can't use him. Any ideas on how I find someone who can do the design even if they aren't the one doing the install?

Randell