Client Has Issue With Remote Hook Up

[123pugsy]

Hi Guys.

We manufacture stainless restaurant equipment.
We built in 2 ice cream wells into a remote buffet table.
These wells are 50" x 11" x 15" deep with 3/8" copper tubes wrapped around and spot welded tightly to them several times around to approximately 90' worth on each.
The walk in cooler guys took the contract to hook them up. Complaint is that they won't come down to temp. They are using 448a gas. 2 HP compressor seems more than adequate.
They tried in parallel and then went to series hook up and same issue.

We have made these identical wells for approx 22 other locations over the last 25 years, where they probably used 404a.

Is the new gas just not good enough? Do we need to use 1/2" tubes around the wells? More length, but same size tubes?

Any ideas appreciated.

[seanf]

Are the design calculations saying it should work?
When in parrallel, did each coil have its own metering device?
What running pressures and temperatures did they get?
Did it have a clear liquid line sight glass?

[pugsy123]

I'm not the service tech. I have reached out to him for answers.

For the first question, the only engineering is that these all worked fine using a different gas.
It seems now with the newer gas, the problem is here. No design changes in 25 years.

[pugsy123]

Sorry, my 123pugsy account has been frozen since I tried to update my email.

[seanf]

If you google "r404a to r448a retrofit" theres a number of articals and industry guides for making the change.

[hotifeh742]

It sounds like you're facing a challenge with your ice cream wells not reaching the desired temperature despite using a 2 HP compressor and 448a gas. Here are a few potential factors and solutions to consider:

Gas Compatibility: 448a (Solstice N40) is a refrigerant blend designed to be a drop-in replacement for R-404A and R-22 in refrigeration applications. However, its performance characteristics may differ slightly from 404a. It's worth checking the specific properties of 448a to ensure it meets the requirements for your system.

System Design: While the compressor size seems adequate, the design of the system, including the length and diameter of the copper tubing, can affect cooling efficiency. Using 3/8" copper tubing is common, but increasing the length of the tubing or using larger diameter tubing like 1/2" could improve heat transfer and cooling capacity.

Installation and System Integrity: Check for any leaks or improper connections in the refrigerant lines, as even small leaks can significantly impact system performance. Ensure that the system is properly charged with refrigerant according to manufacturer specifications.

Environmental Factors: Consider environmental conditions such as ambient temperature and humidity, which can affect the cooling capacity of the system. Make sure the system is installed and operated in a suitable environment.

Insulation: Ensure that the wells are properly insulated to minimize heat transfer from the surrounding environment. Inadequate insulation can lead to decreased efficiency and longer cooling times.

Thermal Load: Evaluate the thermal load placed on the system, including the amount and temperature of the product being placed in the wells. High thermal loads can strain the system and affect its ability to reach and maintain the desired temperature.

Consultation with Refrigeration Experts: Consider consulting with engineers who can conduct a thorough evaluation of your system and offer tailored recommendations based on your specific requirements and constraints.

[GaborArern]

Many thanks to all for the suggestions youve made. You get more sense here in a day than Ive had in months of pleading with the GP or NHS Community Dementia Service.