Technical observation for P&V system offers from 2 vendors. 1. General: 1.1. I suggest to ask for two blowers for the P&V system. One working and one standby. This will ensure continuous availability of P&V system. Similar to other equipment, we can operate one for some time, say a couple of days and operate the other one for the next couple of days. 1.2. We have to understand that in case of failure of this blower, the temperature is going to build up fast in the VFD room and it will not be desirable. 1.3. For effective functioning of this system, we have seal the room on all sides. VCL has to take care of this. 1.4. Considering the superior technology (double level of filters, Humidity sensing, water spray system etc.) offered by APC, the price offered seems to be more competitive. 2. Aerovent 2.1. They are quoting 11000 CMH blower. They are considering 30 ACPH (Air Changes Per Hour). It is good. We usually plan for 12 to 15 ACPH in our previous projects. 2.2. The offered system is not sensor based. The P&V system is meant for continuous operation. 2.3. Please ask them to submit a list of items that are likely to be supplied. 2.4. Starter panel is excluded in the offer. Better ask them to include. We can help in cabling, termination and earthing but they have to bring the panel. 2.5. Scaffolding not included. Please review and if required, ask the vendor to include. 2.6. Better ask Aerovent to mention the brand for all major items. 3. Xavient 3.1. The system offered by Xavient seems to be different. It can run both on Dry or Wet mode based on the humidity conditions. 3.2. The system is connected to a humidistat interlinked with water pumps. Xavient has to confirm that the humidistat is included in their supply scope. 3.3. Lodging and boarding is excluded. Better ask for offer including the same. 3.4. Cables, cable trays they are requesting. Please take a decision based on our preference. 3.5. They had mentioned the brands for all major items. Good. 3.6. The blower capacity is only 10000CMH. Maybe we can ask for calculations for the basis of selection. 3.7. Temperature sensors and humidity transmitters are to be included by Xavient in its scope. 3.8. This system is having two stage filtering arrangement. Better.