Help, quoting for a Hotel?

[expat]

I've been asked to quote for air conditioning in a 19 bedroom hotel. It's a two star with rooms of approx 12m² to 15m². 1st floor 9 rooms 2nd floor 10 rooms.

The manager of a Mitsubishi outlet visited the site with me and put a quote together:

1st floor
aMXZ-8A140VA (14kw) for 7 rooms.
bMXZ-2A40VA (4kw) for 2 rooms

2nd floor
cMXZ-5A100VA (10kw) for 5 rooms
dMXZ-5A100VA (10kw) for 5 rooms
All of the above serving 19 SEZ-KC25VA ductables.

My first gripe here is that while the MXZ-8A140VA has one HP and one LP going to the first floor ceiling area and then being split up by Mitsubishi's distribution boxes to the various ductables. The other three are traditional multisplits. This means unit: ahas 2 pipes, units: b,c,d have a total of 24 pipes.
So 26 pipes coming down from the roof. I was hoping for something a little simpler.

Secondly does anyone else think that 38kw is overkill for 19 rooms * 15m² = 285m² in a hotel which is primarily going to be occupied at night.

I have more to discuss on this but any feed back at this point would be appreciated. Of special interest would be how others would attack this project.

[superswill]

In all our hotels we do its always a VFV heat recovery system (Toshiba or Samsung) mounting the BC boxes/MCU’s/flow selectors (name depending on manufacturer) in the loft or ceiling voids, as most manufacturers are going or gone modular with there condensers getting the right capacity should not be a issue once the indoors have been sized correctly, most decent air con distributors will size and design a equipment schedule if you provide the room sizes, or using the various ac sizing programs out there (ac calc ect ect) with a manufactures VFV design program most available free via download or distributors this can be done by yourself with very little pain


Hope helps

[Jay1553]

38kw sounds about right for 19 rooms at a guess I would use a 2.2kw slim duct which is the smallest capacity of most VRF equipment.

[expat]

Thanks for both the replies. I would like to add that another distributor provided a solution for this project.

A single Daikin 28kw unit on the roof splitting off with reefnets to four ductable units (two on each floor) which then by the aid of air handlers distributed the cooling to each individual room.

Each evap/air handler would have it's own on/off and temp control and each room would have it's own thermostat to demand cooling/heating or not.

A bit more complex for the end user but a bit cheaper (although perhaps under powered) and a lot easier on install, especially as far as condensats are concerned.

Would you guys like to comment on this solution ie, difficulties in regulation, space needed for evap/air handlers. Any thoughts welcome.
Thanks again

[The Viking]

So you are talking about a hotel with different guests in each room....
The nice Mr Ahmed from the middle east who can't sleep if it's colder than 28 degrees in one room, in the next room Miss Ecstasy that cant relax if it's any warmer than 20 Degrees...

Hmm, how would your proposed system cope with that situation?

[frank]

Thanks for both the replies. I would like to add that another distributor provided a solution for this project.

A single Daikin 28kw unit on the roof splitting off with reefnets to four ductable units (two on each floor) which then by the aid of air handlers distributed the cooling to each individual room.

Each evap/air handler would have it's own on/off and temp control and each room would have it's own thermostat to demand cooling/heating or not.

A bit more complex for the end user but a bit cheaper (although perhaps under powered) and a lot easier on install, especially as far as condensats are concerned.

Would you guys like to comment on this solution ie, difficulties in regulation, space needed for evap/air handlers. Any thoughts welcome.
Thanks again
Individual room control for this system would be a NO NO and I wouldn't even consider it. You would just be buying problems further down the line.
VRV/VRF (same thing) is best suited to Hotel installations, especially heat recovery. With a Centralised Controller the hotel receptionist can switch each room off when it's not occupied and on when a guest checks in.
But if it's just a cheap budget then go for individual splits - Fujitsu etc.

[expat]

Thanks for the replies.

Viking, the system proposed had little motors that would shut off ducts to rooms where the desired cooling or heating was met but I do admit I had thought of the problem in between seasons where one room might want warming while another cooling.

Frank, I take it you are talking about a VRV/VRF system that could permit simultaneous heating and cooling to allow for the above. I understand this to be quite a bit more expensive than all hot or all cold.

As for budget, well I'm not sure yet but the customer wants to get rid of the consoles on the walls and the condensing units off the balconies.

[The Viking]

Expat,

We just finished an hotel installation.
After experiencing what their guests expects, I would say that in hotels, your only options is either heat recovery (simultaneous heat/cool) or independent units. Unless there are other forms of heating (radiators) in which case go for cooling only units.

(The example in my previous post is from real life, even if the names has been altered to protect people's privacy)

[sreek]

hey expat
we have done lot of hotels .vrf is best suited for guest rooms whether you chose mitsubishi or daikin.you will save almost 40% in terms of electricl energy.

Go for individual indoor units for rooms and ducted ones in common area.A single treatedfresh air supply for all rooms with each room having approx 30-40cfm.A exhaust system extracting 40-50cfm from the toilets ie:at slight negative pressure with respect to room.

I am a mitsubishi guy.you can have a diversity of .7
ie:if your total indoor unit capacty adds up to 130TR outdoor(condenser)capacity can be 100TR

and go for corded or concealed remote bcos guests can misplace cordless ones

you can also go for card access control systems if budget permits and heat recovery unit instead of seperate exhaust and fresh air supply fans