Heat Pump system for 2100SF Manufactured Home

[icthrooyou]

Hello,

It's been a long time since I last posted here. I've had some difficult health issues, but clawing my way back.

We are purchasing a property which we think may be in need of a new system. We want to do this right and as I understand, there are specific calculations for heat loss and other characteristics of the structure that come into play in choosing the right size unit for your home.

The house is a 2128SF and I've posted a pic of the floor plan below. It is located in the upstate/central SC area and I've heard that heat pumps are favored in this part of the country. The existing AC unit outside has been vandalized with the copper and electric lines cut. We will be having a professional HVAC inspection done tomorrow with an estimate for repair or replacement done by a local company. However, we really need to keep our rehab expenses LOW as possible because we have a large family and several other items on our list that must be completed before we can occupy. So we have been looking for used or discounted equipment as an option.

As it turns out, we just located a new Haier Heat Pump system (HR42A1VAR outside unit with HB4200VA1M25 inside unit) for sale offered at a cost of $1800. This unit is still new in the box and includes the outside unit, inside unit air handler with "A" coil, and heat strip.

My concerns are as follows:
First off, I'm a little confused that the Haier website lists the outside unit as an "air conditioner", but it is advertised as a heat pump.

Next question, is this system sufficient (or potentially so) for a 2100SF home in SC? Here are the specs from their website:

Cooling capacity (BTU/h):42,000
Cooling capacity (Ton):3.5
Heating capacity (BTU/h):41,000
SEER:10
Power supply (Ph,V,Hz):1,208~230,60
Appearance color: white
Net/Packaging dimension of outdoor unit (L*W*H):30 1/4*30 1/4*31 1/2 /32 3/4*32 3/4 *36
Net/Gross weight of outdoor unit (Lbs.):215/238
Compressor type:H20J403ABCA BRISTOL
Air-flow (CFM):2700
Refrigerant type:R22 137.8 OZ.
Piping dimension of gas pipe(mm): 22.22(7/8")
Piping dimension of liquid pipe(mm): 9.52 (3/8")
Connecting method: Sweat

Last question...is this a decent quality system and is it serviceable at reasonable costs compared to other units. I see this system is made in the People's Republic of China, which doesn't thrill me off the bat.

Please point me in the right direction here, thanks!

Paul

[EDJ13]

I don't see an amp draw listed for the unit. You might have to upgrade all the wiring to run this thing.

I think it's a little large for what you want but I'm by no means a A/C person. Check with your contractor.

I'd get in touch with the utility company(s) that will be supplying your gas/electric and work with them. Around here there's a big push for people to upgrade with many rebates available.

[icthrooyou]

Hey, thanks so much for the reply. I've done some additional research and have since received an estimate for a complete system installation from a reputable local contractor. The local salesman says that I need a 5 ton unit due to the heat loss/gain factors involved with the mobile home...crappy windows, 1 skylight, the local climate in SC, vaulted ceiling with modest insulation throughout. I know mobile homes aren't the most energy efficient structures, but a 5 TON UNIT? I know of other folks who have much older mobile homes the same size that are using 3.5 ton units in this area and they are working just fine. Perhaps I'll get another estimate from a competitor.

It really concerns me that you consider a 3.5 ton unit too large and yet the salesman was calculating for a 5 ton unit. I wonder if anyone else can comment on this?

As far as the wiring, the home is a 1997 Fleetwood/Clayton and has a 200 amp service panel, but we'll be sure to check the wiring for proper type and sizing before installing.

I am completely unable to afford any of the three different five-figure installation options quoted by the local contractor, so I've decided to purchase the equipment myself (Goodman 5-ton 15 SEER variable speed system - Outdoor: SSZ140601A, Air handler: MBVC2000, Evap Coil: CAPF4961D6) and hire a qualified installer to hook up and test the system. We have not begun the work yet, but on initial conversations with the installer, he mentioned that we may need to replace the mobile home's standard duct-work, citing that standard mh duct-work is designed for a high-static air handler. Does this sound like an accurate assessment? We'll replace the ducts if necessary to do it right, but the original firm made no mention of needing to replace duct-work in their itemized quote.

Thanks again for the info!

[icthrooyou]

I don't see an amp draw listed for the unit. You might have to upgrade all the wiring to run this thing.

I've totally dumped the Haier option and I'm tentatively going with the Goodman system I mentioned above. I checked the specs and for the 5 ton outside unit, a 60 AMP HACR breaker is required and min ampacity is 34.6. The air handler is rated 5.8 min ampacity with at least a 15 AMP breaker, but it may be more with a heat strip add-on. Either way, we'll be absolutely certain to check the wire runs for proper sizing and type. Thanks!

[icthrooyou]

Here is a drawing of the layout I forgot on the original post. My current concerns are proper sizing of the unit for the heat load on the house. I want to be sure the sales person correctly calculated the requirements before I invest money in a system that isn't right for my home. If I don't need a 5-ton unit, then I can afford a more efficient smaller 3.5 or 4 ton unit. I'm looking at the software demo for HVAC-Calc. Does anyone use this software? Or is there a more reliable way to determine what I need?

[southernbuilder]

I have the same size Fleetwood home I bought new. I ordered it with overhead duct work. The AC unit was a 5 ton Coleman with a heat pump. This was a package unit (one piece outside, not split inside/outside). I believe my breaker size was determined by the Heat Strip KW's and is 80 amp. Is the system in your home currently a "split" unit? Or is it a package unit. My original unit blew a compressor and I decided to replace it. I ended up buying a unit directly from a company i found on the internet. Cost was around $3k with the heat strips and shipping for my Rheem 5-ton Package unit w/ heat pump. I could have saved $1000 by purchasing a Goodman.

[icthrooyou]

Yeah, the equipment we're replacing was a split system with air handler/evap coil inside and outside heat pump unit. I'm also getting my equipment from an internet company that offers free shipping liftgate service to my door. They have some Rheem units that aren't too much more money than the Goodman's, depending on what you want. The prices are low for both brands.

I think you're right about the heat strip determining breaker size. I looked at some of the Goodman spec sheets and they listed breaker sizes on the air handler specs, but it said if a heat strip was added to the system you had to refer to the tag stamped directly on the unit itself to get the right over-current protection.

I've decided to do my own heat load calculation on the house using the HVAC-Calc software. I think it's worth the $49 to know I have the right size unit for my particular situation. I just didn't get the impression the sales person who gave me the quotes before did anything more than a quick "rule of thumb" assessment. If I were a HVAC contractor, I would probably have some type of software or at least a spreadsheet that cold produce a professional and accurate heat load assessment that I could print-out for my clients on the spot. Rule of thumb just doesn't cut it where this stuff is concerned...too many situation-specific variables.

[icthrooyou]

I have the same size Fleetwood home I bought new. I ordered it with overhead duct work. The AC unit was a 5 ton Coleman with a heat pump. This was a package unit (one piece outside, not split inside/outside). I believe my breaker size was determined by the Heat Strip KW's and is 80 amp. Is the system in your home currently a "split" unit? Or is it a package unit. My original unit blew a compressor and I decided to replace it. I ended up buying a unit directly from a company i found on the internet. Cost was around $3k with the heat strips and shipping for my Rheem 5-ton Package unit w/ heat pump. I could have saved $1000 by purchasing a Goodman.

Have you noticed any trouble keeping the humidity in check with that 5-ton unit? I'm just wondering about short-cycling if I have too much cooling output?

I mentioned this above, but no one has commented on it yet. One of the guys giving me installation estimates has mentioned that I need to replace the standard mobile home duct work due to an originally installed "high static air handler". I want to understand what this guy is talking about and whether this is correct or if he's talkin' baloney to increase his installation charges.

Don't know if this has any bearing on the "high static" situation mentioned above, but the unit I've tentatively decided on has a variable speed air handler rated from 0.14" WC wet/0.128" WC dry @ 1000 SCFM up to 0.487" WC wet/0.419 WC dry @ 2200 SCFM. That is for a 5-ton Goodman CAPF4961D6. I'm hoping we don't have to switch out the ducts, but will if necessary.

[icthrooyou]

I've purchased the homeowner version of HVAC-Calc software and find it very easy to use. However, even with the mobile home options selected and with using the worst possible insulation options I can choose (short of NONE), the biggest tonnage rating I can come up with is a borderline 4-ton cooling requirement at 47,391 BTUH heat gain and 79,880 BTUH heat loss. That's with using the "Poor (old homes/farm houses)" construction tightness setting. If I select "Average (normal construction, poor vapor barrier)" tightness, it drops back to a 3.5 ton cooling requirement for 44,922 BTUH gain and 74,730 BTUH loss.

The problem I have is in trusting my own amateur calculations against a supposedly experienced HVAC professional who came to the home and gave me a quote for a 5 ton unit. On top of that issue, I am also getting somewhat conflicting information regarding the need to use specialized mobile home rated equipment due to the supposedly smaller duct work and related high static pressures.

Add to those problems yet another potential conflict with my homeowner insurance company if I choose to go with a system (standard Goodman equipment) that isn't specifically rated for use in "mobile or manufactured housing". The more I research this, the more conflicting info I find...

What I would LIKE to do is to go with a Goodmam system which I can get for a very competitive price shipped right to my door and hire a local HVAC person to install it for me. But I may have to rework the ducts and I have no clue how much that might cost for my situation. I want to stay under $4k for installing this system if at all possible.

[southernbuilder]

@ icthrooyou - I have not had any problems with humidity. I remember when I was researching buying a new unit I visited several HVAC forums for information. I am always skeptical of what a salesman tells me i "need" so i feel your pain. I would think if the ducts were sized properly for the first unit they should be right for your next unit. Thats just my opinion and I am far from an expert in this field. I would look over the HVAC forums and find ones where the "professional" HVAC people give good advice then ask your questions. Good luck!