Originally Posted By DieselEngineer:
I was on Lochinvar’s website last night looking at their Noble line of residential boiler.

Plumber did not provide make and model of replacement boiler. 11k includes 3 new circ pumps to replace the 3 current heating zone circ pump. An indirect heater would be a fourth zone. I’ll take a closer look at the Knight. FW Webb is a big commercial distributor in this area, and they carry Lochinvar. I’ll ask my account rep for work who he’d recommend for an install like this.

Originally Posted By DieselEngineer:
I ran through a few online heat load calculators.  Measured rooms, window sizes, etc. to input the data.

Better Built NW: 35,000 BTU/Hr
Loadcalce: 60,000 BTU/Hr
FW Webb: 55,000 BTU/Hr

I'm ignoring the first result. My current Weil-McClain oil-burner has a net rating of 93,000 BTU/Hr and an EPA rating of 103,000 BTU/Hr.

It looks like I can use a boiler rated around 80,000 BTU/Hr, again, aiming at a high efficiency mod-con.

FW Webb has these options in that size range:
Navien NHB-80H, Propane, 10:1 turndown ratio, $1,800, 5 year parts and 10 year heat exchanger warranty
Lochinvar NKB080L, Propane, 10:1 turndown ratio, $2,200,m 5 year parts and 10 year heat exchanger warranty

My house has three zones (1-Basement, 2-first floor and master bedroom on second floor, 3-rest of second floor)

I will install a low loss header/hydronic separator to maintain a boiler loop and a secondary loop. I'll also add in a zone for an indirect hot water tank. A Lochinvar Squire 40 gallon indirect heater is $1,300.

Does this make sense?
For what its worth, the Navien combi boiler is $2,000 and the Lochinvar combi is $2,500

Originally Posted By laxman09:
Here are my two estimates so far. Neither did the loss/gain survey.

Originally Posted By SWIRE:
Have you played around with Grok or any other AI when it comes to sizing a system or running calculations?  I spent several hours using Grok the other day to troubleshoot a cooling issue I have.  I gave it all the details of the house and it ran the calculations. I don't fully trust it but I at least have more information to go on.  

Basically the company I paid to upgrade everything about 20 years ago did the bare minimum for a standard "old house" and didn't factor in my 10 ft ceilings, R-2 walls (not a typo 2 bricks and 1/2" of plaster), and 72" tall single pane windows of my 120 year old house.  I finally got real answers for why 20 years ago my brand new heat pump was not able to effectively cool my house on hot days.  

Some things that Grok pointed out were the air ducts and flex tubing were too small for my living room where the air stratifies instead of getting enough air to properly circulate it.  My return vents are too small, by about 50%, which also limits the air movement.  The heat pump is also under sized for the application which is why on hot days the living room, on the north side of the house with only 1 exterior wall, would end up 6-8 degrees warmer than what the thermostat was set at.  

Using Grok I would describe as talking to the most patient and knowledgeable expert ever, where I could supply additional random details at any time and get a polite and more informed response.  

Here are some points that Grok pointed out.  Anything sound odd to you or does Grok's reference data seem correct?
Blower: 1,000-1,200 CFM split across 9-12 vents is stretched thin.
Returns: 344 sq in total (6x24 + 2   10x10 with 8-inch ducts) handles 1,200 CFM at 500-700 FPM but limits higher flow for 10 ft ceilings.
 Current blower (1,000-1,200 CFM) and 12x24 return (288 sq in) max out at 1,200-1,440 CFM tight (600-720 FPM). Furnace spec likely supports 1,600 CFM (80% furnaces often do), but confirm.
Ductwork: 2,040 CFM max supports 12 vents (e.g., 2x 10x10, 2x 4x12, 8x smaller) at 135-170 CFM each current 6-inch flex bottleneck (50-67 CFM) fixed with 8-inch (75-100 CFM).

Originally Posted By ZW17:
Who supports parts in your region, the best?

In other words, who’s going to have parts the very next day if your boiler goes down?

Originally Posted By ZW17:


I'm not happy they didn't do the heat loss/gain survey. It's really rare to find anyone who does these days.

I'd go with option #1. I don't like Lennox (proprietary parts can be expensive), but they are adding a 5" filter (awesome) and a 1yr preventative maintenance plan.

I also have a personal vendetta with Carrier (screwed us badly on a large commercial project) so they will never see the inside of my house, but that has nothing to do with their equipment and your install.  

Warranties are equal.

Everything else is pretty simple on a furnace swap out.

Maybe clarify a few things...

1. Is the furnace going to be put on a pad or legs to stay off the ground (rusts the bottom out quickly if they are on the concrete).
2. Where is the condensate being run to? Floor drain? Pump? You don't want furnace juice (condensate) running down an old steel/iron floor drain, it will rot it out very quickly.
3. I am assuming the old PVC piping is being reused and is in good shape? No mention in the quotes.
4. Only mention of a thermostat is in the one quote, and it's to reuse the existing stat. You good with that? Now is the time to upgrade, and I would suggest you do. Stats have a lifespan too, and I wouldn't want a 20yr old stat on a new system.

The "last look" game can play to your advantage, if they want the work, they will give you a better price. I try and do it all the time in my field. Unless there are engineered blueprints, anyone can build that system anyway they want, some will cut corners and use cheap equipment, I want the opportunity to compare apples to apples with the low bidder, educate the owner, and find the right solution to the job.

Originally Posted By laxman09:


Both come with 1 year tune up service/maintenance. I actually requested a smaller filter as I don't mind replacing them often as I have dog/cat/3 women with hair blowing around. I could get a thicker filter on #2 by asking.

1. #1 Said they would raise up the furnace off the ground higher then my current which is on bricks . #2 didn't mention raising it off the ground.

2. Condensate runs to my sump pit 3 feet away.

3. Some of the current PVC pipe will be reused. It's in good shape but both stated they'd run new from the furnace to meet current where it meets the wall.

4. I have an ecobee currently that I like. Both said they would maintain that and it would run the systems fine.

Estimate #3 told me they carry a variety of brands. The first two didn't propose using any others when I asked as they claimed warranties were better long term.

#1 always wants to redo the return vents from the ceiling down for better flow into the blower. The Lennox also has a rebate which is nice.

Originally Posted By ZW17:


Sounds like all things are fairly equal.

Two other things I thought of....
1) Ask about any training certs the company holds for the installers doing the job.
2) Request that their top service tech performs the startup on the new equipment with a full written startup report. You don't want the install monkey's performing a startup and testing and balancing.

Originally Posted By laxman09:
Daikin two stage.  12 year parts/labor warranty. Contractor did a manual J eval at my request, or some virtual eval where he went through the house with his tablet scanning everything.

Will reuse my aprilaire filter box.

https://www.ar15.com/media/mediaFiles/450791/1000003019_png-3525576.JPG

Company has a good reputation and he shared some before/after install pics, the work looks very clean.

@zw17

Originally Posted By ZW17:


I like the 12yr warranty.

I like that they did some kind of survey, although I don’t know of any iPad app that lets you scan things to do such a survey? Did they measure the depth of the attic insulation? How about walls?

I love the idea of the two stage, it’s a big improvement over a single stage furnace and will save a lot on gas.

A little more expensive, but sounds like it may be worth it with a solid reputation.

Originally Posted By ryandushku:
I just got off the phone with my HVAC guy actually. He's going to come over next week with some numbers and check a few things for a new Central air unit. Our 1988 (Yes, 1988) York finally took a dive last fall. He said wants to do it soon before the refrigerant switch

Originally Posted By ZW17:


The refrigerant switch has already taken place.

That boat sailed about 6mo ago.

Originally Posted By ZW17:
That is correct, but without a W2 (2nd stage heat) wire, the furnace will bring on 2nd stage automatically if the call for heat isn’t satisfied within 10min (may vary depending on manufacturer).

If the thermostat controls W2, it’s usually initiated based off of time or temperature. For example, what say you come home from work and the heat is in setback at 65°, you bump it up to 70°, the thermostat automatically knows it needs to have a 5° temp rise so it will bring on W2 almost instantly.

Usually with a thermostat, it’s either temperature initiated with a 2° temp rise or more, or a 10 minute time period where the call for heat has not been satisfied.

Originally Posted By laxman09:


They said it's a 15 min delay for stage two and they never use W2 wire. I'll see how it runs for awhile I guess.

Originally Posted By ZW17:


It’s not terrible. May take a bit longer to warm up but you won’t be using any extra fuel to do it.

Originally Posted By HK-Slap:
I'm in SW Ohio and currently have a 3 ton Lennox heat pump HVAC system (15 yrs old) and I want to replace with a more modern system. What are some recommendations for brands that are reliable and considered top tier? I'm not impressed with Lennox, as the unit has been troublesome over its history.

Originally Posted By CJ7365:
How to HVAC installers feel about just installing, I purchase my HVAC unit, condenser/heat pump, air handler and coil, and have them install it.

I understand about doing the load testing, but if my unit has been cooling and heating just fine, is there really a need to do another load test?

Originally Posted By BeardownAZ:


I've never heard its better to be undersized, we're are you getting your info? If it cant keep up that is not ok, it's too small. Even on extremely hot days.

Originally Posted By 03PSD:
I have a rheem system in a house i just bought that is 2.5 tons. The house is 3 stories including 1/2 finished basement, 3800 sq/ft total.  Not sure how old the system is because the label is completely faded, but at least 10 years. The only thermostat is on the main floor. The basement stays freezing cold when the thermostat is set to 70, the mail floor stays at 70 and the upstairs where the bed rooms are is at least 76 or higher depending on outside temp. House was built in 1951. I'm not going to make it thru the summer sweating my ass off while trying to sleep. A window shaker is not an option. What's the correct way to fix this situation?

Originally Posted By ZW17:


Can you walk into Burger King with a pound of ground beef and request they make you a burger for 75% off the price?

That's how professionals feel when customers buy their own equipment and ask them to install it.

Originally Posted By Piratepast40:
Our AC unit finally went out yesterday.  Called around and finally got a tech out today to troubleshoot.  He says it's only running sporadically on one phase.  Can get it to run for a short period of time but then it quits.  Unit was installed in 1996 so I believe we've gotten out moneys worth out of it.  He says that if we want to use the refrigerant piping that we now have, don't try to run it again because of the risk of the compressor burning up and releasing oil into the refrigerant.  It won't run very long anyway the way it is now. and the compressor shuts off after a few minutes or after about an hour.  

He says the furnace is in surprisingly good shape.  The secondary Hx shows very minor evidence of leakage but not enough to worry about yet.  The main blower motor is leaking oil out of the sealed bearings, but other than that, in good shape.  However, the tech and sales guy say's we're on borrowed time on that furnace and that they would not install a new evaporator under the old furnace.  I agree whole heartedly.  I've done some of minor maintenance on the furnace like replacing the ignitor and fan assembly, so it hasn't gone without any maintenance.

We're in Salem Oregon in the heart of the Willamette Valley.  Temps are generally mild with summers sometime above 100 but not usually. They're predicting 98 in a few days but then going down to low 90's and mid 80's after that. Winters are mild as well with typically a few snow flurries every year but rarely staying below freezing for more than a few days.  

House is a 3 br single story ranch with about 1550 sq ft with crawl space.  The sales guy came out and spent a few hours measuring the rooms, duct diameter, returns and all rooms.  He also measured all the window area in each room.  He inspected the crawl space for duct layout and condition, and attic for insulation.  We had windows replaced about 10 years ago and added attic insulation up to 20" about 12 years ago so we're in pretty good shape in that area.

He says that, based on all factors, including duct and return diameter and area, would be looking at a 1.75 ton unit.  Quoted a Goodman 2 ton, 17 SEER AC unit and 2 stage Goodman furnace up to 40,000 BTU.  Furnace is a high efficiency, two stage, model GC9C960403BN.  AC is a model number GLXT7CA2410.  Installed price is $16,168.  He cautioned about going larger than needed because of short cycling and humidity concerns.  It's been a loooong time since I've been through Navy A/C & R and R-11 schools but I do remember that concept.  

I plan on getting at least one more quote and expect a thorough inspection before the company just throws out a number without measuring the glass area and duct diameters.  

Does the first inspection and estimate seem reasonable?

Originally Posted By ZW17:


Running on a single phase?

Only runs for a while a quits?

None of this is adding up.

Originally Posted By Piratepast40:

I'm probably using the wrong terminology.  He might have said that only one of the windings had a good reading.  In any case, I DO know that sometimes the compressor will kick in and other times it will not.  

I don't want to be second guessing the cause of a dead horse.  It's dead, or in death spasms, and I need a new one.

Are you saying that measuring ducts and glass area doesn't make sense either?  I'm serious when I'm asking because I was under the impression those were part of heat load calculations.