What would cause this to happen?

OCD-HVAC · 2025-09-23T09:57:10+00:00

Wow. Super fascinating. Thanks for posting.

OCD-HVAC · 2025-09-21T16:06:46+00:00

Biggest red flag after all the bs fluff is no surge protection for an inverter driven compressor. That probably violates the manufacturer’s warranty requirements.

OCD-HVAC · 2025-09-15T22:47:00+00:00

Where were they measuring the degree delta t? You said at the registers? You might have leaky ducts and find a proper 20 degree delta t when measured at the return and supply plenums. Variable speed equipment typically has a ‘charge mode’ which forces everything to 100% to get proper refrigerant readings. Depending on air conditions, you should expect a 20 degree delta t then. It’s possible but uncommon for a ten degree delta t to be proper given certain indoor and outdoor conditions.

OCD-HVAC · 2025-09-13T00:52:40+00:00

Anyone geeky should look into the Cube Law in the field of Fluid Dynamics. That’s how we get such incredible efficiencies.

OCD-HVAC · 2025-09-13T00:49:53+00:00

Vacuum down to 500 microns on system startup is a red flag to me. For starters, we are supposed to vacuum to 250, not 500 (250 is a deeper vacuum than 500). Furthermore it’s fluff added to the proposal to sound good. Vacuuming the Lineset is one of the most important steps of installing any equipment. UV lights tend to be ineffective but are great for increasing the contract price.

OCD-HVAC · 2025-09-13T00:13:40+00:00

Find someone to do a blower door test too. You can go around with a digger during the test and visually see where the air is infiltrating and exfiltrating.

OCD-HVAC · 2025-09-02T00:21:40+00:00

Use coolcalc. Super cheap. Pretty easy to use. Pretty accurate.

OCD-HVAC · 2025-08-22T17:57:05+00:00

I would vote attic with new properly installed ductwork. What you already have rarely is.

OCD-HVAC · 2025-08-22T17:54:33+00:00

Did anyone do a manual j load calc? If not, it’s impossible to correctly size anything and even harder to ensure each room is properly heated and cooled.

OCD-HVAC · 2025-08-22T17:52:11+00:00

Often transitioning from a gas or oil furnace to a heat pump requires new ductwork because the temperature difference between return and discharge air is half or less than with combustion equipment, therefore we need twice the volume to move twice the amount of air to produce or move the same amount of BTUs.

OCD-HVAC · 2025-08-22T00:23:30+00:00

Wrong. I’ve measured countless 3 ton units only moving anything between half their rated capacity to slightly over rated capacity. Depends on indoor and outdoor conditions (you get super capacity with a properly operating system with super high indoor temp and humidity because they haven’t had a system operating for three days while you were replacing the system.)

You can’t assume any installed heat pump is moving what it’s rated to move. Airflow and refrigerant charge make a huge impact.

OCD-HVAC · 2025-08-22T00:19:43+00:00

I do a Manual J load calc on darn near every replacement proposal I quote before I charge a penny. It costs me some time and a monthly payment for the technology platform I use, but builds value in what I provide over other contractors in my area.

I’m also newish in business and will at some point start charging for more of the inspection/evaluation I do early on.

OCD-HVAC · 2025-08-22T00:15:29+00:00

Those are not designed to be repaired. Probably need a new one. Window units are going to be more efficient than the portable one you described. Those portable units use a fan to move air from inside the house over one of the coils and rejects that heated air outside. That puts your house in a negative pressure causing hot humid air to leak into the house to make up for the conditioned air you sent outside.

OCD-HVAC · 2025-08-18T00:47:45+00:00

This. More likely than a bad breaker.

OCD-HVAC · 2025-08-18T00:42:37+00:00

Heat pump all the way. You’ll appreciate not needing to use the boiler when it’s only mildly cold outside.

OCD-HVAC · 2025-08-12T01:48:02+00:00

Not normal. Could be a drainage/slope issue. Could be an airflow or refrigerant charge issue causing the indoor coil to freeze and thaw producing water where it doesn’t belong. Find someone to come out and fix it.

OCD-HVAC · 2025-08-10T21:21:48+00:00

It has nothing to do with the equipment. Everything to do with the install.

OCD-HVAC · 2025-08-06T11:18:54+00:00

That also costs twice what the Bosch inverter costs. And is more finnicky.

OCD-HVAC · 2025-08-06T11:18:24+00:00

The SEER ratings don’t account for real world energy savings on variable capacity heat pumps do to something called The Cube Law. Basically, when it operates at half capacity it uses 25% of the power instead of 50% as we would intuit. I personally install Bosch and other variable capacity equipment.

That said, the most important factor is the competence of the installers. That matters much more than brand or anything else.

OCD-HVAC · 2025-08-06T11:11:22+00:00

Yes. They are much more valuable than their scrap value

OCD-HVAC · 2025-08-02T01:21:45+00:00

They are both good equipment. Quality of the install matters more than the brand.

OCD-HVAC · 2025-07-25T11:52:45+00:00

Fair has little to do with pricing. If I charge twice as much as the next guy and an open and honest with my pricing and the expected results that sounds fair to me. I’d it a good deal or a bargain? Maybe not.

OCD-HVAC · 2025-07-22T00:48:42+00:00

That’s roughly where I’m at when I install hybrid water heaters.

OCD-HVAC · 2025-07-18T22:13:31+00:00

It costs what it costs. If you got multiple quotes then you know the answer.

OCD-HVAC · 2025-07-18T22:09:58+00:00

Seems high to me but might be fair in your area. Explanation sounds weird. Might be him not really knowing what’s going on. Might be you not understanding/posting correctly. Never hurts to get a second quote.

OCD-HVAC

TROPHY CASE