Heat and Cool simultanously - efficiency

[grumit]

Hi,

I'm having an HVAC system designed for a commercial building. We have a meeting room, offices and front lobby. The mechanical engineer told me that we cannot use one unit for all areas and zone it since the meeting room can get hot when many people are in, while the lobby can get cold. So a single unit cannot serve both zones. This makes sense, but under this scenario we are going to have cooling on one room and heating on the next room. It sounds terribly inefficient.

Does anyone has a suggestion for a more efficient method?

Thanks,

Grumit

[Coolmaniac]

Hold the meetings in the lobby? Tough to say without a lot more info, listen to the engineer.

[flange]

Not sure of your configuration, but there are at least two systems available that can offer you individual room control, and simultaneous heating/cooling. Daikin is one and Mitsubishi City Multi is the other. Each is a good system, with many features and energy recovery to allow simultaneous heating/cooling. They are extremeyl quiet, and very energy efficient, although for some contractors and engineers, they just don't get it. We have installed a bunch and they work great. There are others here who have had similiar results.

[grumit]

Thank you flange, I'll suggest these options.

[rotaryfrk]

It's not uncommon to run Cooling and Heating systems simultaneously. I have a building cooled by a chiller using vavs with reheats in them. While the chiller is running the boilers run pretty much most of the day to warm up cool spots and also help dehumidify. Many large and small buildings operate this way.

[local 832s]

Its absolutly possible. VAVS with reheats is all you need. As said before, it will reheat the air dehumidy and it goes along its merry way. This is common practice in well designed office buildings. I would look for a new Engineer if this is all he/she has.

[grumit]

> Hold the meetings in the lobby?
Can't do that!-)

I've listened to the engineer. I understand this is the straightforward and conventional way, but I'm not happy since it's not efficient.

Meeting room is about 400 SF. Lobby and office area is about 2000 SF. Stand alone building.