Load calc and suggested Bosch setup, please critique.

[ctdd]

It's been a long journey, but I've finally narrowed it down to a proposal that sounds right for me and wanted some professional opinions please. House is a 3000 sq/ft 4 BR/3.5 bathroom colonial in New England built in mid 80's with no existing ductwork and hydronic baseboard oil heat. This is the proposal:

1) Remove existing boiler, baseboard radiators, and oil tank.
2) Install 2 x BOVA36HDN1M20G Bosch M20 2-3 Ton Inverter Driven Heat pump paired with 2 x BVA36WN1M18 Bosch M18 3 Ton Air Handler. Second floor/attic install consists of one central return, one supply trunk and 8 supply outlets. 1st floor/basement install consists of 7 floor supplies and 7 floor returns, condenser outside on plastic pad.
3) Bosch BCC100 x 2 zones (upstairs/downstairs)

1 for the downstairs, AHU installed in unfinished basement, and 1 for the upstairs, AHU installed in walk up attic that is outside the building envelope.

Now three things that I want to change before it's finalized- 1) I noticed he paired the BOVA/IDS 2.0 outside unit with the BVA/IDS 1.0 inside AHU. I'm going to be asking him for AHRI numbers and will point that out when I do. 2) I'd prefer the Ecobee to the Bosch BCC100 units, unless anyone has had great experiences with the Bosch thermostats. 3) One central return for the 2nd floor seems insufficient.

Attached is the heatload calc. Thanks in advance for any help or criticisms. I went through a lot of HVAC salesmen to get to this point, this guy was the most thorough, I just want to make sure I'm doing the right thing before sinking a fully loaded Honda Accord payment on it because I'll never be able to afford to replace it until my kids are through college.

[Bazooka Joe]

What’s your backup heat source going to be when they are down due to no heat call, or what are you using to help temper the discharge air temperature while in defrost if anything? No mention of KW heaters sizes in the bid..

Make sure they elevate those Bosch OD units off the pad, for better water drainage during defrost. Probably will say the height requirements in the install guide on the OD unit?

Ask them what type of added training/classes they have had on these particular systems, as they look like fairly complicated systems, and not your average Heat Pump install.

[ctdd]

I'm going to have two gas fireplace inserts installed for backup when my tankless water heater is installed, roughly the same time my boiler is removed. I asked about resistance backup and he said it won't be necessary. A no heat call meaning my heat pump is down? Is that different (longer repair?) than when my boiler is down and I have no heat or am I missing something intrinsic to heat pumps? Thanks again.

Edit: To answer your other question, they are certified Bosch installers, but I did not ask specifically for their qualifications and training. I didn't even think to ask about elevating the outside unit, I assume you have to because of snowfall in New England right?

[Bazooka Joe]

I'm going to have two gas fireplace inserts installed for backup when my tankless water heater is installed, roughly the same time my boiler is removed. I asked about resistance backup and he said it won't be necessary. A no heat call meaning my heat pump is down? Is that different (longer repair?) than when my boiler is down and I have no heat or am I missing something intrinsic to heat pumps? Thanks again.

A no heat call meaning my heat pump is down? Yes that is what I meant, but it sounds like you have back up heat with the gas inserts. Are you going to be satisfied with Air Conditioned air temperatures coming out of your supply registers for a few minutes while in defrost? as basically while your in defrost, your in A/C mode?

Not saying it’s a bad thing but those Bosch OD units and I believe the ID Air Handlers are manufactured 100% in China and exported to the USA. Bosch has a partnership with Midea to produce those units. IMO The only thing German is the badge, and the engineering side.

[ctdd]

A no heat call meaning my heat pump is down? Yes that is what I meant. Are you going to be satisfied with Air Conditioned air temperatures coming out of your supply registers for a few minutes while in defrost? as basically while your in defrost, your in A/C mode?

Not saying it’s a bad thing but those Bosch OD units and I believe the ID Air Handlers are manufactured 100% in China and exported to the USA.

I know what you're saying, baseboard heat is far superior to heat pump heat. I know there are several drawbacks to relying on heat pumps as your sole source of heat in New England, but I haven't found a way to solve most of my issues and stay under budget until this setup. I've read good and bad things about Bosch, but the reality is, they fit the budget and the needs and at least on the outside units, the boards and inverter are made by Mitsubishi. I will ask him to include a price for resistance backup heating strips, if it isn't too much I think you're right that it's a good idea.

[Bazooka Joe]

I know what you're saying, baseboard heat is far superior to heat pump heat. I know there are several drawbacks to relying on heat pumps as your sole source of heat in New England, but I haven't found a way to solve most of my issues and stay under budget until this setup. I've read good and bad things about Bosch, but the reality is, they fit the budget and the needs and at least on the outside units, the boards and inverter are made by Mitsubishi. I will ask him to include a price for resistance backup heating strips, if it isn't too much I think you're right that it's a good idea.

Yes Mitsubishi inside, Japanese in name only? Who knows where those parts are actually made. Read a older thread here said they where made in Vietnam. Is that a bad thing? I don’t know is it? It’s a global economy nowadays. Parts come from all over the world nowadays in many applications, not just HVAC.

Hopefully this Contractor is versed in Bosch installs and set up and ductwork correct and commissioning report is all good.

[ctdd]

Yes Mitsubishi inside, Japanese in name only? Who knows where those parts are actually made. Read a older thread here said they where made in Vietnam. Is that a bad thing? I don’t know is it?

I hear you. I'd rather use Trane, my last Trane lasted 16 years until I sold my house and it was still going strong. They just don't make a heat pump that does what I need it to at the price I need it to be. Most of the Trane dealers that came out tried to push me to Mitsubishi so...

Everyone on these boards has said over and over again don't worry about the brand, worry about the installer. I'm doing my best to vet the installer on my end, I just need help to know if his game plan is solid or if I need to come up with a new one. You've given me two new things to ask him re: height of heat pump off ground and cost of resistance heating strips added on.

[Bazooka Joe]

https://www.bosch-climate.us/files/B...03.2018_US.pdf

Section 2.3 discusses height elevation of OD unit above pad.

Chuck full of info for you to read, refrigerant line size selections, field charge set up, the list goes on and on. The more closely they follow the install guide the better the set up, along with proper ductwork. The install guide of the indoor selection has a lot of info also.

https://www.bosch-climate.us/files/B...04.2018_US.pdf

Asking for that AHRI match is a good idea, tell the Contractor they are dealing with a knowledgeable homeowner IMO, not to mention you will need one if your state or local utility company offers rebates. Needs to be a certain minimum SEER and HSPF to qualify.

[ctdd]

The Bosch IDS 1.0 didn't meet the rebate standard because it was 9.5 instead of 10 HSPF, even though it met the SEER. With the Bosch IDS 2.0, they have thankfully raised it to 12.5 so it meets the rebate requirement. AHRI is something I had no idea about until I read this website.