What is size of upstairs zone and size of main floor zone?

What size is furnace for upstairs?

Heating fuel is nat gas?

And to be clear, basement is unfinished and has no ductwork for conditioned air?

Size and number of returns for main floor and upstairs zones?

Other than age, what if any were the problems of these old systems?

What exactly are you looking for in comfort and efficiency from new systems?

Post back

IMO

Thanks very much for your reply.

The upstairs is 1100 sq ft. The main level is the same, as is the basement.

The upstairs furnace is 50 BTU.

The heating is natural gas.

There is ductwork in the basement that supplies the main floor. The basement is unfinished currently. That may change.

There are six vents upstairs with one return in the hall area. The return is 12x24.

There are eight vents downstairs with one return in the hall area. The return is 12x24.

I was told that the unit upstairs had a leak/crack in the compressor that could possibly leak carbon monoxide. There are marks on the outside of the unit that looks like burn marks. The heating unit performed fine the last time we used it before we found out about the burn marks. It is about 25 years old and about 8 SEER. The cooling unit seems to run almost all of the time in the summer.

The downstairs unit also performs ok but needs a serious duct cleaning due to water from a pipe bursting in the kitchen getting into some of the ducts. We haven't used it in quite a while.

The house has humidity problems sometimes (window condensation and my indoor hygrometer can get near 80% in the summer but is around 50% in the winter) and we would like a system that can take care of that and be more efficient. The upstairs unit seems to run all of the time in the summer. The stat is usually set around 75. I was told that 16 SEER two-stage would fit the bill. Other ac companies told me I needed nothing more than the typical 13 SEER. Some family members have asthma and I also want something that will help with that.

How can I tell if my ductwork really needs to be enlarged?

Thanks much for your input

You have to tackle this air infiltration humidity problem. I assume source is basement. What do quoting dealers suggest? There is always a whole house dehumidifier but that does nothing except remove humidity not the source of the humidity.

I like AmStd HVAC but do not like the equipment dealer has selected or the size of the furnaces.

I would say your returns are undersized. My suggestion is to add another return to each floor.

Your terminology about cracked compressor is confusing. You mean furnace heat exchanger?

IMO

Thanks so much for your input.

The quoting dealers suggest a more efficient AC than my current 8 SEER will solve the humidity problem, and that a 16 SEER 2-stage would handle that the best (one dealer suggested that 13 SEER was sufficient). They said that a dehumidifier is built into these newer units.

There is currently a standalone dehumidifier that runs continuously in the basement.

Can you suggest the AmStd equipment that could possibly solve my problems and the appropriate furnance size?

I did mean cracked heat exchanger. Sorry about that.

The last dealer wanted to include a 10 year labor warranty on the AC in case the undersized returns damaged the compressor instead of upsizing the returns. Compressor would then be replaced and installed at no charge. Good or bad idea?

Thanks again.

"The quoting dealers suggest a more efficient AC than my current 8 SEER will solve the humidity problem". Huh?

"They said that a dehumidifier is built into these newer units." It is?

Unless you misunderstood what these dealers said, I'd keep looking.

Like above post from skin, lots of nonsense coming from these dealers about your humidity issue and features of new HVAC to address this.

Before condemning these dealers for misinformation, you need to go back and ask for clarification.

Still say the source of the humidity has to be addressed. The idea that dehumidifier runs non stop says a great deal. What is setting?

It is true that two stage condensers will help on dehumidification. I would want this type system for main floor level with dehumidify on demand set up.

But the suggestion that your new systems will cure your humidity problem is not correct.

IMO

This post was edited by tigerdunes on Mon, Dec 1, 14 at 7:47