What do I need to know about heat pumps?

[Roly]

Location would be helpful , almost mandatory.  How about adding to your profile ?


What might be best in the N. Montana won’t be great in So. Florida.

The min. SEER is the sweet spot.

The improvements over the years all get incorp. into the base products. Moving up the food chain really only get you features you may or may not want.

See what rebates are available, and how much they are.    Most rebates have a minimum seer requirement.   As Blackhat go for the installer first then the brand.    Most of them feature a brand and will stock a lot of parts for that brand.   Roly

[overland]

See what rebates are available, and how much they are.    Most rebates have a minimum seer requirement.   As Blackhat go for the installer first then the brand.    Most of them feature a brand and will stock a lot of parts for that brand.   Roly

It's possible to do it yourself. I installed a MrCool system at my parents' place in Florida a month ago. It has an outdoor compressor and four indoor "mini-splits." The do it yourself packages come with pre-loaded refrigeration lines that connect the indoor and outdoor units. It was pretty simple, though a little tricky to lay out all out.

[Cabinet Monkey]

It's possible to do it yourself. I installed a MrCool system at my parents' place in Florida a month ago. It has an outdoor compressor and four indoor "mini-splits." The do it yourself packages come with pre-loaded refrigeration lines that connect the indoor and outdoor units. It was pretty simple, though a little tricky to lay out all out.

"Splits" might be great for a room or two but they aren't suitable for a whole house.

Additionally, while they may be a simple DIY project - installing a traditional whole house unit like the o.p. is talking about isn't quite so simple. First off - the lines don;t come precharged like a split.  Which means you'll need a gauge set, a scale and the ability to use them.  And you'll need to go buy the refrigerant and it'll usually be more than you need.   Then there's the increased size and weight of the units which require a helper.  You'll almost certainly require some sheet metal work to mate the new system to your existing duct work/plenum - more tools and skill.  You'll also have to braze the lines - which is still more tools and skill.

None of those are beyond most talented and motivated individuals, but it's far from easy and simple.  Might save you money (might not) but it won't save you time.

[Terry W]

Location would be helpful , almost mandatory. 
The min. SEER is the sweet spot.

I'm in the upstate of South Carolina, near Clemson / Greenville.  The heat pump will service a fully finished 1600 Sq/Ft walk out basement with 10 ft ceilings. 65% is below grade. Two double sliders and 5 standard double pane windows. Exterior is hardie plank over 2x6 with R19 fiberglass insulation. Interior walls are 2x4 with fiberglass inset from poured concrete walls.

[BaileyNo5]

It's possible to do it yourself. I installed a MrCool system at my parents' place in Florida a month ago. It has an outdoor compressor and four indoor "mini-splits." The do it yourself packages come with pre-loaded refrigeration lines that connect the indoor and outdoor units. It was pretty simple, though a little tricky to lay out all out.

I have a Mitsubishi mini-split system and a natural gas stove in a small 2 bedroom house (the BRs and bath also have small electric heaters). It works great for cooling the entire house in the summer. The inside unit is mounted high on the wall of a room with a vaulted ceiling, which I think impacts it's ability to maintain a warm temp down near the floor in the winter. Glad we have the gas stove to provide some heat.

Depending on the size of the house and the layout, you can get pretty good coverage with the compressor/mini-split units.

[Terry W]

Well it happened. It developed a leak and lost it's magic juice. HVAC tech said the replacement cost for R22 (or comparable) is running $125 per pound. On a 17 year old unit, that's not worth it.  I'm waiting to get the prices on a couple of quotes. One of the reps walks around, eyeballs the area and says I need a 2.5 ton for the basement because of the square footage. I told him that would be WAY oversized. I did an online manual J and it comes in around 1.2 tons. The existing unit was a 2 ton and it loafed along even during the heat of the summer.

[Cabinet Monkey]

DO NOT engage anyone who does not do a manual J calc.   EVER

[Snipe Hunter]

DO NOT engage anyone who does not do a manual J calc.   EVER

I have to agree. No calculations, no sale.

[meackerman]

installer....
  yeah it only took the company that installed my HVAC system 8 return visits to get it working right....and then 4 years later they found another thing the original installers did wrong, which they fixed under warranty.


I should have known when I asked the installer guy how much gas pressure the heater needed and he replied about about 11.  11 what?  11 <shrug>.  no units, no clue.

15 PSI that the gas pipe has is way different than ~11 WC that the heater needs.

they blew out two gas valves before they figured out they hooked into the propane line in the wrong place.  then I had my propane guy come in and replace all their crappy gas line work.  That was only 2 or 3 of the 8 return trips it took them.


So yeah find a good installer, spend a bit more for them if you have to.

[Terry W]

I thought I should do a quick follow up on my post.

So I had three different companies come out to give me a quote. Even though 70% of my ground floor is underground (walk out basement), every one of the job estimators just want to know the square footage and number of registers in the rooms. NONE of them would do a manual J.  I got the impression that none of them even knew how. They all wanted to quote me an exact replacement for the failed unit I have, even though I told them that, from living with it for 16 years, it was way oversized.

I eventually went online and found two websites that I could do my own manual J’s. I did both and they matched. (well, close enough) When the fourth HVAC company showed up, I sat down with the guy, gave him the manual J and TOLD him what size I wanted installed.  He had never seen anyone do their own calculations before. 

They gave me a fair price and I signed them up. The install was quick, clean and professional.  Thanks for all the advice. I’m happy I took the time to get the right size installed by the right company.