r/askHVAC

Sorry in advance for the long post…

We are in the final days of a year-long full gut renovation, which included all new mechanicals and HVAC. Our home is a 1960 expanded cape (the expansion was done 15 years prior to us owning the home) and has one large primary bedroom upstairs with a bathroom and walk-in closets and nine foot ceilings. This week has had temperatures of 90+ and when turning on the AC for the first time since the system was completed about a month ago, we noticed that the upstairs is getting barely a trickle of cold air out of the four vents (two in the bedroom and then one each in the bathroom and closet). It was unbearably hot up there but the first floor and basement were comfortable. The basement was actually freezing.

Our GC initially said that closing the vents in the basement would allow the cold air to be directed to the upstairs bedroom but it’s still barely a trickle. Then he said it might possibly be that the ducts are the incorrect sizing because they did not redo the system for the second floor and will have his HVAC guy out to check what is going on. The solution might be opening a wall and redoing it. However, our contract states the following for HVAC:

Remove existing furnace and AC unit. Remove existing duct work, vents and
registers.
• Contractor will provide and install two zone central air heating and cooling unit.
Provide one new condenser on a new pad.
• Provide and install all required sheet metal ductwork, supply and return air to
and from new air handler.
• All new duct and flu work for entire house. Supply and install needed diffusers.
Vent out laundry, hood, and exhaust fans for bathrooms.
• Install new wall/ceiling registers and return air grills.
• New forced air HVAC system. The condensing unit to be installed on the rear yard.
• Install Rheem 4.5 Ton 85k BTU 14 SEER; 92% efficiency with coordinating Air
Handler Units. (Contractor will perform appropriate sizing calculations for all
mechanical units)
• Grilles assume (2) units per room.
• All bath, laundry, hood and dryer venting.

The all new duct and flu work for the entire house and contractor will perform appropriate sizing calculations should mean this is on them, correct? I do not want to have to pay extra for this. Am I reading the contract scope for work correctly that the upstairs was supposed to be included?

Had a mildew smell from HVAC for 2+months. The odor is in the returns and drifts into the house. Worse in evening/overnight. Sometimes its a sour smell as well. Last night was the worst. Both returns smelled mildewy sour and even a sour smell behind the fridge, in the cabinets next to fridge, and along the floor. Could be a different source but it's the same smell that's in the returns. Did all the HVAC checking and cleaning, even have a new furnace and AC but that made the odor stronger. Dozen professionals can not find the cause or source. Plumbers seem to not know much. No one wants to do a smoke test. Any suggestions??

We just move and our garage was converted to a bonus room by the previous owner - just tiled floors and painted drywall. Plan on turning it into a man cave and wanted to add a mini split system to provide heating and cooling. I found some quality and reliable units for around $800-$1000 and curious what would the average cost be to have it installed.

I’ve been in the automotive industry for 6 years and am tired of it, ready to leave working on cars as a hobby and find another trade to pay the bills. Starting at an HVAC company on the 1st and just wondering what tools you guys can’t live without, nice to haves, wish you’d gotten sooner, bonus points if it’s something that I can grab out of my automotive toolbox. Boss said we mainly do residential calls, a small amount of commercial, and we also install water heaters. Boss said only thing I need day one is a razor knife and a headlamp and they’ll give me a tool list, just wondering about things that may be helpful and not on the tool list without going crazy dropping money on tools out the gate. Also he said to bring a hammer drill and an impact drill but googling the tools it looks like a hammer drill is just a regular drill which I already have, and an impact drill is an impact driver which I also already have? Or am I wrong and it’s terminology I don’t understand?

2700 sq ft. 4 level home, half is split level and half is basement with a main level. I am looking at replacing furnace (> 30 yr old Lennox Pulse Furnace, still works but efficiency has gone down) and AC (> 20 yr old, quit working), and received 2 quotes. To give you an idea of my weather, see the screenshots below, avergae daily air temp is below ~35 F from December - May with Jan - Mar is sub zero monthly temps.

Option 1) Trane 80K BTU 2-stage 96% FUE Gas Furnace + Trane 2.5 Ton 13.4 Seer 2 central air conditioner for $12,132.00 (amount after deducting all possible rebates and discounts)

Option 2) Bryant 60K BTU Preferred 2-stage 97% FUE Furnace + Bryant 37MUHAQ24AA3 (2 Ton Crossover Heat Pump) + Bryant  CAAMP2517AMA Coil + Honeywell  YTHX9421R5127WW thermostat for $11,200.00 (after deducting all possible rebates and discounts)

Looking for some insights from the group. My biggest concern is choosing a crossover heat pump over the traditional het pump or regular A/C. Thank you so much!

https://preview.redd.it/9t0wqnyq3c2h1.jpg?width=910&format=pjpg&auto=webp&s=f9d09cd42f7dd02f2d49cdab968838b1baceec1e

https://preview.redd.it/p6xnpmyq3c2h1.jpg?width=900&format=pjpg&auto=webp&s=067ce4488ed8d9237ef4dae28274b5b8a728cb33

Can anyone tell me if this is a reasonable price for the service?

My external AC unit is empty. It's happened before, so I need to fix it. I got the following estimate on a unit that is less than 30 days from being out of warranty. I do know that the coild can be replaced. But, I have to get someone reliable to do it.

"No refrigerant in the system but can’t confirm because the service caps are glued. Service ports need to be replaced and also the refrigerant line set needs to be replaced. Once the line and service ports are replaced we will pressure test the unit with nitrogen to make sure the indoor coil and outdoor coils are ok. If there coils are leaking then we will provide additional estimate for repairs or replacement of parts.

Also the disconnect box outside needs to be replaced. They bypassed the disconnect box and it is not safe. Box needs to be replaced as well.'

Price for repairs is $2,450.00 for the listed items/repairs.

My HVAC system recently stopped working, and a technician came out and told me that both the indoor and outdoor compressors are bad, so he recommends replacing the entire system instead of repairing it. I’m located in Philadelphia, and my current setup is a 100,000 BTU 90% heater/furnace with a 4-ton AC system. He quoted me around $11,000 for a full replacement with a new Goodman system (inside and outside units).

I also had another HVAC company come out, and they told me they only install Carrier systems. I’m currently waiting on their quote to compare pricing.

This was originally my first home, but now I rent it out to tenants, so I’m trying to balance reliability and cost. Does $11k sound like a fair price for a full Goodman replacement in the Philadelphia area? Also, for a rental property, would you choose Goodman or Carrier?

Yesterday was ridiculously hot and humid. I turned on my central air conditioner and found it to be slow to cool and ineffective.

I let it run anyway. This morning I found it frozen all the way out to the condenser. I turned it off and thawed it out today.

I restarted the unit a couple hours ago and it has cooled the house down somewhat but it’s less impressive than previous performance.

The lines outside the house - one warm one cool- are not super cold - but were frozen from overnight.

There is good airflow from the vents and I can see through the filter.

1. Did freezing up for a prolonged period screw up the system?

2 what are causes for freezing up beyond poor air flow?

3 what questions didn’t I ask that a should have?

My husband and I just had a new AC system installed where there wasn't one before. We used the ducting from our forced air heating system. It's finally gotten warm enough for me to run the AC and this is probably the third or fourth day I've used the new AC. Yesterday, I started noticing that the entire house suddenly reeks of cat urine. We do have three cats and our litterboxes used to be right next to the HVAC/furnace unit. That corner of the basement collects a lot of moisture and I noticed that it was starting to amplify the cat smell, so I eventually moved the litterboxes to a much dryer area of the basement. Even so, now when it's rainy, the smell sometimes pops back up, but it's never overpowering or through the whole house. This new smell with the AC is. So I'm assuming that the smell has to do with that corner of the basement having historically had a problem with moisture and cat urine smell. I've done some research and read that although that spot historically has a problem, a new, properly-installed AC shouldn't amplify it like this. Is this true? If so, what could be wrong? And what can I look for or do to try to make things a bit better before calling someone out? We had a really bad experience with our HVAC contractor so I wouldn't put it past them to overlook something or do something wrong. I did check the filters - they are new and facing the right way. Is the slot that they go into supposed to be sealed up as much as possible? There's also a piece of PVC pipe sticking straight up, blowing air into the basement as well as a random piece of round ductwork blowing cool air into the basement as well. The air coming out of them is cool but doesn't smell. Could these still have something to do with it?

Please help - I'm due with our first baby in 3 weeks and the idea of bringing our baby home into a house that reeks of urine is causing me a lot of anxiety.

It's around 85 to 90° today, and about 60% humidity outside.

When I ran the central air the indoor temperature was around 78°, it's been about 3 hours and now it's about 72 to 73° in the entire house.

The humidity in the house when I started was around 58% and it's either stayed the same in some rooms or dropped only about 2 to 3%.

This is a 2600 ft² colonial home and have a 3 ton unit, the air handler is in the attic. The attic right now is about 120°.

All windows are completely shut. I'm not sure if this is normal, I'm a new homeowner and I didn't run the air conditioner last year.

During the warm months, what mini split settings are you using? For context I have three mini splits in my house. One in my bedroom, one in my toddler’s bedroom, and one downstairs.

The mini split in my toddler’s room makes the room extremely humid on the cool setting. When it is on the dry mode, it makes the room very cold. Ideally I would like to be able to shut her door so she can sleep easier however that worsens these problems.

Both of the other two machines have issues, but don’t impact the air quality as much as my toddler’s.

We also have issues in the winter time when we want to use the heat mode. Excessive heat is pushed out of my toddlers mini split, causing her room to get extremely hot, especially if her door is closed.

For the amount of money that we spent on these, I am so upset with the way they work. I feel like I have tried every combination of settings without any luck.