Hi All, New home, with the 'guts' built by a (rather poor) contractor. Walls are 6-8" foxblock ICF with energy sticks. Attic insulation is R50. So should be very tight. Single stage gas furnace. Installed by amateurs who insist they are a professional HVAC company. Builder refuses to acknowledge problem and his trades' incompetence. Not having a lot of luck bringing them back, and we are speaking through lawyers at this point...let's just say that during the walkthrough we discovered the HRV inlet/outlet lines were reversed, so little/no fresh air was being drawn into the house. Anyways, we got the HRV lines swapped, but now its 74F on the main floor, and only 64F on the 2nd floor. Supposedly they balanced the system (but I wouldn't count on it). The home has cold air returns in all rooms. At floor level in bedrooms, but near the ceiling in bathrooms (where they connect to the HRV). When the heat ducting leaves the furnace, it splits into 3 - basement, 2nd floor, 3rd floor. The furnace is in the basement. The HVAC trade put dampers on the 2 round ducts that head upstairs, but nothing on the basement duct. Hubby has been adjusting the two heat duct dampers to the upstairs, and closing the heat registers on the main floor, but its only increased the temperature by <2degrees. It's awful. We wanted the 2nd floor to be warmer since we are always cold when we sleep. Suggestions for improvement? We are contemplating adding a damper to the square duct, since that's the shortest run and closest to the basement. I'll add that this house doesn't have a huge amount of windows (all triple pane argon filled, and is designed old school 'closed concept'. So I'm surprised by the cold temps.

1: Do leak testing around the upstairs simply to establish that the cold ISN'T from poor window install (fitment).

2: Sight unseen, I'd say get a decent HVAC contractor out to inspect the install. Even if it's on your dime, as it's something you can hand off to your lawyer.

3: Beyond that, putting a damper on the first-floor run might help. It really depends on exactly what these yahoos did to realize the second floor run. If it's running through any attic/service area above the second floor ceiling, get up there and look. Even if it's in conditioned space, make sure those runs are insulated.

We were onsite during and/or immediately after the hvac install. Nothing penetrates into the attic.
We had sound issues earlier due to gaps around windows, and confirmed for ourselves that they are now tight. (We even foamed a few ourselves to make sure they were tight).
The 2nd floor ducts run in a opening in the main floor open-web-truss joists, then go up through the main floor walls and into the 2nd floor open-web-truss joists. We did gripe at the contractor to reseal a few of the ducts where the tape wasn't stuck properly (or the paint-sealer cracked), and even redid most of it the night before the drywallers came...

Sounds like a poor HVAC installation and perhaps even a poor HVAC design. This could simply be the case that there is insufficient heat gain being applied to the upstairs rooms (i.e., the upstairs heat loss is greater than the heat gain that can be provided). Was a proper room-by-room heat loss analysis done for this building (e.g., ACCA Manual J8 or equivalent) so the heat source and duct work could be properly designed and sized? Was the HVAC contractor licensed or is a HVAC license not even required at your location?

Contractor claims (on a piece of unsigned, undated, photocopied piece of paper from their distributor, not their own company) that they used ASHRAE. (We are in Canada, so they said that's why they didn't use Manual J or such).
The HVAC trade hired at least 3 different subtrades for the build, so it's been a gong show. Builder won't hold them responsible for anything, claiming 'it was all done by the book' so it's been very frustrating.

Did they zone your system for future controls? If it splits into 3 like you say install the 2nd floor tstat and zoning controls. That would compensate for the real problem.

Also, In a tight open concept this isnt uncommon as the heat from bodies, cooking, plasma screen, lights, laundry keep your furnace from kicking on and as a result your unoccupied 2nd floor isnt getting any heat as your house coasts off this supplemental heat.

Or, Oversized single stage can short cycle so you dont get enough runtime to heat the 2nd floor.

Or, sum tin wong with your duct design; flow issue. Can measure flow at each register.

I wouldnt assume any house was tight until its tested.

Unless your house is massive, a single stage furnace is builder basic, like $7-8k with AC here. HRV wont count in court unless theres something really screwed up. Most contracts dont allow for homeowners to get attorneys fees, and actually demand arbitration first. What Im saying is, in the states youd spend at least $6k to sue so often for something like this its not really a winning proposition unfortunately. Canada may be more fair.

Greentree - yes, it is built for possible future zoning. They wanted extra $$ for that despite we had a requirement for multi-thermostat control in our original plans. So we may get stuck upgrading anyways (but at least with hopefully a better HVAC company!)
The challenge is we have a 1-year warranty period and can't make any changes to the house until it's over. But its hovering around 32F outside right now, so I don't want to see how bad the temp difference will be at -30F (we live in the cold north...)
We were wondering if two NEST thermostats might allow for better heating, as then it would call for heat depending on which rooms were occupied.



Our house is 1325 sq feet per floor, so 3975 total? Basement and main floor are 9', second floor is 8' ceilings. Our total cost of HVAC for the house was ~25k.

All three floors are ICF, only the rafters are wood. We were onsite during majority of the build (3+ days a week, and weekends) so we caught a lot of things as they went wrong, and did our best to get fixed what we could. Unfortunately, the HVAC is one thing where the builder wouldn't budge. (Hell, we only got the heat turned on back in March because *I* had to figure out what was holding up the turn-on-the-gas permit...and we only figured out why a call for heat turned on the AIR CONDITIONING in JUNE, and why the air conditioning was making a terrible buzzing noise (stalling) - because they programmed the thermostat wrong, and I had to call in a 3rd party company to fix it! At least I got a formal written 'suggestion' that the builder hire pros to program thermostats )

Unfortunately, we have to go through the warranty to get anything fixed, for the duration of the first year. Which requires the builder to admit things are broken (which so far means irrefutable proof) before he'll even consider fixing them. :\

So if you have to wait a year what are you asking? Buy one of those oil filled radiator heaters, they work good.

Regular digital tstat can be wired in parallel upstairs but will obviously overheat downstairs when you have it calling for heat, would also heat up your gas bill this winter.

What size is the furnace? Maybe leave all doors open for a day to help see if it is a supply/return problem.

greentree - In theory I have to wait a year...but in reality the warranty company may have found a loophole and may effectively cancel my first year of warranty. I also need options to try and get my builder to fix it, or to fix it myself, and say fuckit to the warranty. The reality is that the warranty has little value when no txt, phone call, or lawyer-drafted formal notice results in any action on his part. :\

The furnace is an 80,000 BTU/hr furnace. It was oversized based on an energy study I had a 3rd party company do, but they said they needed to oversize it in order to get sufficient airflow through the house.

All the interior doors of the house have been left open 100% of the time. It's just me and my husband in the house, so we see no need to close the doors.

There is nothing wrong with an ASHRAE heat loss analysis. It is actually a better and more accurate method than ACCA Manual J8. ASHRAE should be accomplished by an engineer as it is not simplified like ACCA for HVAC technician use. Both must be be properly done in any event. Hopefully, it was done properly and your furnace was sized accordingly. I suspect you will have to get a competent HVAC contractor onsite to sort out your issues. In the meantime, perhaps get some temporary options in place to make your home more comfortable until your issues are properly addressed. Unfortunately, HVAC contractors are often hit or miss and your story isn’t all that uncommon. Sorry about your frustrations.

Posted By Geergirl on 30 Nov 2017 04:02 AM
But its hovering around 32F outside right now, so I don't want to see how bad the temp difference will be at -30F (we live in the cold north...)

My house in much more temperate maryland has great imbalance issues in shoulder seasons. I find that the colder it gets and more constant demand on the heat pump, temperatures level out much better.

Can you control the fan speed with your therm? Maybe run the fan on low 24/7.

Is the HRV ducted with the furnace duct work or independently? If you turn off the HRV for a day or two does the heat get better? Just a thought- if you have three separate heat runs from the furnace you could make the 1st and second floor independent buy adding a 2nd system and dedicate one to the 2nd floor. One furnace for a whole house vs 2 smaller (or more) units - sure higher cost for additional units but not a lot but vastly improved comfort.

For a quick and cheap test, I would add a damper to the basement duct run. Close it or throttle back to force more air in to the upper floor ducts and maybe you will notice a difference. Can't imagine why they would add dampers to two runs, but not the 3rd.

Posted By 3cityblue on 26 Dec 2017 03:09 PM
For a quick and cheap test, I would add a damper to the basement duct run. Close it or throttle back to force more air in to the upper floor ducts and maybe you will notice a difference. Can't imagine why they would add dampers to two runs, but not the 3rd.

If all runs are dampered it's possible to restrict flow through the heat exchangers to the point that the equipment is damaged.

OK. So assuming the basement is not used as primary living quarters, why would you not damper that and leave one of the other living quarters runs un-dampered (presumably to the 2nd floor which seems to be having the most problems.)? The whole system sounds wonky but some easy and cheap modifications might solve or at least help track down where the problem(s) might be.